Metric Prefixes for your projects

Metric prefixes are pretty easy to understand and very handy for metric conversions. You don't have to know the nature of a unit to convert, for example, from kilo-unit to mega-unit. All metric prefixes are powers of 10. The most commonly used prefixes are highlighted in the table.

Prefix	Symbol	Power	Factor
yotta	Y	10²⁴	1,000,000,000,000,000,000,000,000
zetta	Z	10²¹	1,000,000,000,000,000,000,000
exa	E	10¹⁸	1,000,000,000,000,000,000
peta	P	10¹⁵	1,000,000,000,000,000
tera	T	10¹²	1,000,000,000,000
giga	G	10⁹	1,000,000,000
mega	M	10⁶	1,000,000
kilo	k	10³	1,000
hecto	h	10²	100
deka	da	10¹	10
deci	d	10^-1	0.1
centi	c	10^-2	0.01
milli	m	10^-3	0.001
micro	µ	10^-6	0.000,001
nano	n	10^-9	0.000,000,001
pico	p	10^-12	0,000,000,000,001
femto	f	10^-15	0.000,000,000,000,001
atto	a	10^-18	0.000,000,000,000,000,001
zepto	z	10^-21	0.000,000,000,000,000,000,001
yocto	y	10^-24	0.000,000,000,000,000,000,000,001

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Construction Procedure of Surface Road Side Drainage-PART 1 (with picture)

Surface water ( i.e., rain water) that falls on the ground surface such as; open field, paved areas or road surface, roof tops etc are channeled to a main drain naturally or through a constructed channel which is referred to as drainage. Procedure for construction of a common drainage (trench) (1m x 1m U drainage) (reinforced). includes; I. Marking Of Alignment: The surveyor marked out the alignment for the trench to be dug. II. Digging/Excavation: The surveyor marked out the dept of the trench to be excavated with a mechanical excavating machine. For a 1m x 1m drainage, the mathematical process of obtaining the required dept is to sum together the dept of the required drain + base + blinding. For dept: A drain of dept1000 mm, base of 150 mm and blinding of 50 mm. Hence 1000mm + 150mm + 50mm = 1200mm (1.2 m) So an excavation of 1200mm (1.2m) is required from the to level of the road surface. For width:

Construction Procedure of Surface Road Side Drainage-PART 2 (with picture)

V. Next step is laying of concrete base on the blinded surface and the positioned reinforcement. A concrete base of 150 mm is to be laid or cast on the blinded floor, concrete grade C20 of ratio 1:2:4 is allowed (See concrete grading and mix ratio). A guiding panel is placed into position to guild in the laying of the concrete base in order to achieve a uniformly alignment base edge, thickness and width, also to manage concrete material while pouring. The base is cast with the U shape reinforcement bottom in between the concrete base achieving concrete cover below and above. VI. After setting and drying of the concrete base, next is to position the side wall panel form work. The floor base is marked to give the required one meter (1000 mm) internal width where the panel will be positioned. The panel wall spacing is 100mm, and wall height of 1000mm (1 meter), the panel is lubricated, clipped and prepared to accept the Concrete.

Ring / Pipe Culverts Construction procedure

Culvert is an open/close drain structure that allows water to flow below a road. It’s like a tunnel carrying a stream of water flow. A Ring/Pipe Culvert Procedure for construction of a common Ring/Pipe Culvert (road junction culvert) includes; I. Marking Of Alignment: - The surveyor marked out the alignment for the trench to be dug. II. Digging/Excavation: The surveyor marked out the dept of the culvert to be excavated with an excavating machine. For a 1m pipe culvert, the mathematical process of obtaining the required dept is to sum together the total width of the pipe + base + blinding. For dept: A pipe of width 1000 mm, base of 150 mm and blinding of 50 mm (though optional). . Hence 1000mm + 150mm + 50mm = 1200mm (1.2 m) So an excavation of 1200mm (1.2m) is required from the to level of the natural ground (sub grade level) surface. For width: A minimum of (2.5 x width) m is advisable.

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