Fundemintals of Material ScienceDescrição completa
piramids science
Research on the science of Arabic lettersFull description
Improvisation of Science Apparatus Why improvise ? •
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well-designed simple or improvised apparatus of good quality will help the pupils to understand the idea behind the experiment more easily overcome the problem of lack of apparatus save money by using local materials : often help pupils develop positive attitudes towards science 3 benefits if pupils construct apparatus ; acquire manual skill learn to apply principles of science supply school laboratory with equipment • • •
Use of Simple Apparatus •
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no fear of breaking or damaging as with expensive apparatus may lose accuracy in quantity measurements measurements : training pupils to make estimation of the
degree of accuracy is more sensible than trying to get the “right” textbook answer Is it worthwhile improvising ? •
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The idea of improvisation is to make only what is worthwhile and to buy what cannot be improvised satisfactorily limited funds can be stretched : more equipments can be made available to more students by producing locally-made equipment, repair & maintenance would be easier time factor : locally-made equipment can be acquired faster
Categories of Science Equipment 1. Apparatus •
piece of equipment or a set of pieces which when used, can establish the validity of a sc. concept directly
2. Model •
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an equipment, usually in one piece which when properly used, can facilitate an understanding of a sc concept or a group of related sc concepts through indirect illustration it cannot validate concepts used by teacher when direct observation through the senses is inconvenient, difficult or impossible eg. Eye Model = to illustrate the inner structure of the eye
3. Support Item •
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a piece of equipment which by itself cannot illustrate or establish validity or concept, but it is useful only in providing support for sc experiments eg. Distilled Water Dispenser; Overflow Can
Considerations for Improvisation •
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should not be carried out in a haphazard manner but only after careful study and analysis starts with an idea / purpose : the need to save money to produce a device that can facilitate the teaching of a difficult concept cost-benefit analysis : commercial costs & benefits improvisation costs & benefits cost of improvisation may be > commercial cost, but improvised tool > superior in use
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necessary tools
necessary tools to be used in constructing the improvised equipment
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necessary skills
basic skills (carpentry) : woodwork, metalwork construction materials
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cost of materials should be kept to the minimum use discarded materials / recycled materials : from pupils process of construction
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aim should be for functionality refinements can be made testing of final product
Equipment Evaluation can be carried out : during workshop and field testing to detect defects and to find ways of improving it before making a commercial purchase of an equipment to determine its performance benefits and to compare its benefits with other commercial ones 9 point considerations : •
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functionality : must perform the role assigned to it internal visibility : internal parts necessary for concept formation must be clearly seen reliability : should be able to function at all times durability : should be able to withstand wear & tear, and also resist deterioration with time (depends on materials used) appropriate size : should be easily seen & manipulated by pupils 2 ways of using apparatus / model : o class demonstration : large enough for all to see o individual or group work : need not be so large but must be durable finishing : finished product must be neat & attractive pleasant to the eyes
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ease of maintenance :minimum need for maintenance portability and storage : should be easily carried and use up a minimum amount of space when stored safety : should be safe to use , no untoward accidents may happen
Selected Items for Improvisation •
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Physics : The Ripple Tank Production of parallel light rays Rear Mirror Projector Improvisation of a Dark Room The Electricity Pegboard Some weather instruments : rain gauge 1 : bottle, funnel, cylinder rain gauge 2 : large tin, cylinder, funnel making a Hair Hygrometer Chemistry : Laboratory Glassware from Bottles Wet Paper Cooling for Cutting Glass
Light Bulb Glassware Watch Glass from Light Bulb Petri Dishes Simple Alcohol burner Holders, Supports & Stands Wooden Screw Clamp Tripod Rack for Light-Bulb Glassware Test Tube from Egg Container Plastic Materials Plastic Wash Bottle Aspirator Apparatus to Determine Volume of a Solid Daniell’s Cell Safety Screen Flap Type Combination Glass and Plastic Materials: A simple distilling apparatus Styrofoam cutting for Maths & Sc Teaching : Use of soldering copper
Use of kitchen knife Use of tin can Use of glass tubing Use of cork borer Use of band-saw Use of hotwire cutter Micro-chemistry and substitutions
