Point carrom

A variant often popular with children or an odd number of players. Play is as above accepted that all players try to sink all carrom men, regardless of color. The nine carrom men of one color are worth one point each and the nine carrom men of the other color are worth two points each. The red queen is worth five points and may only be captured by pocketing another carrom man on the same or subseqent strike. A player reaching 17 or more points is the winner; otherwise the winner is the player with the most points after all carrom men have been pocketed.

A trackball is a pointing device consisting of a ball housed in a socket containing sensors to identify the rotation of the ball about two axes—like an upside-down mouse with an exposed protruding ball. The user rolls the ball with the thumb, fingers, or the palm of the hand to move a cursor. Large follower balls are common on CAD workstations for easy precision. Before the advent of the touchpad, small trackballs were common on portable computers, where there may be no desk space on which to run a mouse. Some small thumb balls clip onto the side of the keyboard and have integral buttons with the same function as mouse buttons.
When mice and trackballs still had chopper wheels, trackballs had the advantage of being in contact with the user's hand, which is generally cleaner than the desk or mouse pad and doesn't drag lint into the chopper wheels. The late 1990s advent of scroll wheels, and the replacement of mouse balls by direct optical tracking, put trackballs at a disadvantage and forced them to retreat into niches where their distinctive merits remained important. Most trackballs now have direct optical tracking which follows dots on the ball. Some mice, in place of a scroll wheel, acquired a small trackball between the ears, useful in maps, and other circumstances calling for scrolling in two dimensions.
Cache Memory

A CPU cache is a cache used by the central processing unit of a computer to decrease the average time to access memory. The cache is a smaller, faster memory which stores copies of the data from the most often used main memory locations. As long as most memory accesses are to cached memory locations, the average latency of memory accesses will be closer to the cache latency than to the latency of main memory.

When the processor needs to read or write a location in main memory, it first checks whether that memory location is in the cache. This is accomplished by comparing the address of the memory location to all tags in the cache that may contain that address. If the processor finds that the memory location is in the cache, we say that a cache hit has occurred; otherwise we talk of a cache miss. In the case of a cache hit, the processor immediately reads or writes the information in the cache line. The proportion of accesses that result in a cache hit is known as the hit rate, and is a measure of the effectiveness of the cache.

In the case of a cache miss, most caches assign a new entry, which comprises the tag just missed and a copy of the data from memory. The reference can then be applied to the new entry just as in the case of a hit. Misses are relatively slow because they require the data to be transferred from main memory. This transfer incurs a delay since main memory is much slower than cache memory, and also incurs the overhead for recording the new data in the cache before it is delivered to the processor.
Water pollution

Water pollution is a large set of unfavorable belongings upon water bodies such as lakes, rivers, oceans, and groundwater caused by human activities. Although natural phenomena such as volcanoes, algae blooms, storms, and earthquakes also cause main changes in water quality and the environmental status of water, these are not deemed to be pollution. Water pollution has many causes and characteristics. Increases in nutrient loading may lead to eutrophication. Organic wastes such as sewage inflict high oxygen demands on the getting water leading to oxygen depletion with potentially severe impacts on the whole eco-system. Industries discharge a variety of pollutants in their wastewater including grave metals, organic toxins, oils, nutrients, and solids. Discharges can also have thermal effects, especially those from power stations, and these too reduce the available oxygen. Silt-bearing runoff from many activities together with construction sites, deforestation and agriculture can reduce the penetration of sunlight through the water column, restricting photosynthesis and causing blanketing of the lake or river bed, in turn damaging ecological systems.

Pollutants in water consist of a wide spectrum of chemicals, pathogens, and physical chemistry or sensory changes. A lot of the chemical substances are toxic. Pathogens can apparently produce waterborne diseases in either human or animal hosts. Alteration of water’s physical chemistry includes acidity, conductivity, temperature, and eutrophication. Eutrophication is the fertilization of surface water by nutrients that were previously scarce. Even many of the municipal water supplies in developed countries can present health risks.
Education System

Schooling occurs when group or a society or an individual sets up a curriculum to educate people, usually the young. Schooling can become systematic. Sometimes education systems can be used to promote doctrine or ethics as well as knowledge, and this can lead to abuse of the system.

Life-long or adult education have become extensive in many countries. However, education is still seen by many as something aimed at children, and adult education is often branded as adult learning or ultimate learning.

Adult education takes on several forms, from formal class-based learning to self-directed learning. Lending libraries provide cheap informal access to books and other self-instructional materials. Many adults have also taken advantage of the rise in computer ownership and internet access to further their casual education.