Hot and Cold Water Systems in Buildings: Key Concepts
What Determines Water Hammer?
- The cutting time of the liquid mass flow of water. The parameters that determine water hammer are:
- Kinetic energy = ½ * m * v2. A higher speed results in more kinetic energy surge.
- Water velocity
- Pipe length
- Time of valve closure
- Stopping of lift pumps
Measures for Pipes Through Walls and Floors
Always place a pass-through and fill the slack space with a soft and waterproof material.
Maximum Speed in the Network
To avoid noise or vibration, the maximum speed is set to 2 m/s.
Read MoreEngine Cooling Systems: Components and Functions
Cooling Water
Cooling water: For a few holes made in the engine block around the cylinder, the cylinder head to the explosion chamber, and the exhaust valves, a current of water [is used]. Water is responsible for absorbing heat. This is called a water chamber or water jacket. The water enters the engine through the bottom of the cylinder block and out the highest, in order to avoid the formation of pockets of steam.
Forced Circulation
Forced circulation: The circulation of fluid to transfer heat from
Read MoreBoiler Systems and HVAC: Operation and Efficiency
Boilers
A boiler is an enclosed vessel that provides a means for combustion heat to be transferred into water until it becomes heated water or steam. The hot water or steam under pressure is then usable for transferring the heat to a process. Water is a useful and cheap medium for transferring heat to a process.
When water is boiled into steam, its volume increases about 1,600 times, producing a force that is almost as explosive as gunpowder. This causes the boiler to be extremely dangerous equipment
Read MoreBoost Web App Speed: Client & Server Performance Tips
Web Application Performance
Performance Issues
- Client-side
- Server-side
Client-Side Performance
- Minimize HTTP Requests
- Fewer requests per page rendering mean faster time.
- Combine files such as scripts, images, etc.
- CSS Sprites, Image maps, etc. for images.
- Combine multiple JS files, manually or using a tool like YUI compressor.
- Remove duplicate scripts.
- Reduce Content Size
- Reduce transfer time.
- Remove unnecessary tags.
- Compress files (Browser supported: Gzip).
- Minification of Javascript and CSS:
- YUI Compressor,
Liquid Crystal Display Properties and Technology
Director (Vector Director)
The direction of orientation present in a liquid crystal, up or down to the bottom of the page, can be represented by a vertical arrow. There are always two possible choices to aim toward the principal. The two directions are equivalent in the liquid crystal, so any choice is good. The molecular direction of preferred orientation in liquid crystal mesophases.
Electric Field Influence
In general, liquid crystal molecules have permanent or induced electric dipoles, both along
Read MorePlastic Properties, Types, and Manufacturing
Properties of Plastics
Lightweight
This provides comfort when loading and transporting objects or plastic containers.
Impermeable
We can produce fabrics that protect us from the rain, or pipes that carry water or gas.
Photodegradable
Continued exposure to sunlight degrades them and makes them more brittle over time.
Electrical Insulator
We can protect ourselves from electrical accidents if we isolate steel cables with plastic.
Tough (Not So Fragile)
We can manufacture windows, bottles, or lenses for impact-