Kamis, 26 September 2019

TECHNOLOGY EXPO


Date         : July 15-18 2019
Time        : 11 am - 3 pm
Location  : SMAN 3 Bandung

Eligibility : Open to all student in Bandung - please bring your student card for verification. If you isn't a student you can join this event by pay for an entrance ticket just for Rp50.000.


Technology expo is an event that aims to introduce new technological discoveries that will be useful in the future. Therefore, in this event there will be a lot of advanced technology from the nation's children that will be displayed.

There will be a seminar from people who are experts in the field of technology on Tuesday, 16 September 2019.



Lion

Hasil gambar untuk lion
Lion is a species in the family Felidae. It's a muscular,deep-chested cat with a short, rounded head, a reduced neck and round ears, and a hairy tuft at the end of its tail. It is sexually dimorphic. The lion is an apex and keystone predator, athough some lions scavenge when opportunities occur, and have been known to hunt humans, although the species typically does not.

Scientific classification
Physical Description
Lions have strong, compact bodies and powerful forelegs, teeth and jaws for pulling down and killing prey. Their coats are yellow-gold, and adult males have shaggy manes that range in color from blond to reddish-brown to black. The length and color of a lion's mane is likely determined by age, genetics and hormones. Young lions have light spotting on their coats that disappears as they grow.
Without their coats, lion and tiger bodies are so similar that only experts can tell them apart.
Size
Lions stand between 3.5 and 4 feet (1 and 1.2 meters) tall at the shoulder. Males grow to lengths of 10 feet (3 meters) and have a 2 to 3 foot (60 to 91 centimeter) tail. They weigh from 330 to 550 pounds (150 to 250 kilograms). Slightly smaller, females grow to lengths of 9 feet (2.7 meters) and weigh between 265 and 395 pounds.
Native Habitat
Lions inhabit a wide range of habitats, from open plains to thick brush and dry thorn forest. Except for a small population of the Indian lion subspecies that remains in the Gir Forest of northwest India, lions now live only in Africa, from the Sahara's southern fringe to northern South Africa.  They are absent from equatorial areas dominated by moist tropical forest.
Food/Eating Habits
Lions primarily eat large animals that weigh from 100 to 1,000 pounds (45 to 453 kilograms), such as zebra and wildebeest. In times of shortage, they also catch and eat a variety of smaller animals, from rodents to reptiles. Lions also steal kills from hyenas, leopards and other predators. At times, they may lose their own catches to hyena groups. Lions may also feed on domestic livestock, especially in areas near villages.
The Smithsonian's National Zoo's lions eat ground beef, which is commercially produced to meet the nutritional needs of carnivores. Twice a week, they receive knucklebones or beef femurs, and once a week they receive rabbits, which exercise the cats' teeth and jaws.
Social Structure
Lions are the world's most social felines. They live in groups of related females, called prides, which may comprise several to as many as 40 individuals, including adults, sub-adults (between the ages of 2 and 4) and cubs, plus one or more resident males. Abundance of prey availability plays a significant role in the size of a lion pride. Pride mates associate in sub-groups within the pride.
Females usually stay in their mothers' prides for life, unless food scarcity forces them out. Young males are driven from their prides when they grow large enough to compete with the dominant males (usually between the ages of 2 and 4). They create coalitions, usually with brothers and cousins, and search for a pride to take over. Males entering a new pride will kill all cubs that cannot run from them. Adult males that are fortunate enough to achieve residency within a pride hold tenure for an average of two years, often leaving due to eviction by another coalition of males. In India, female and male lions live apart, joining only to mate.
Males take on most of the defensive duties. However, both males and females mark their territories by roaring — which can be heard up to five miles away — and scent marking with urine. Females raise the cubs and are the primary hunters, although males will sometimes join females during a hunt. Depending on the prey item, several lions may stalk prey from different angles to within 100 feet (30 meters) before attacking the targeted animal. Nomadic males must hunt alone or scavenge from other animals.
Reproduction and Development
Females are receptive to mates for a few days several times a year, unless they are pregnant or nursing, and mating spurs ovulation. They typically give birth to a litter every two years.
Females usually give birth to one to four cubs after a gestation of about 3 1/2 months. Cubs typically nurse for six months but start eating meat at three months. Due to dangers, including starvation during times of food shortage and attacks by male lions taking over prides, up to 80 percent of lion cubs die within their first 2 years of life.
Lifespan
Lions in zoos may live into their late teens or early 20s. In the wild, a lioness may live up to 16 years, but males rarely live past the age of 12.

Sabtu, 14 September 2019

Nikola Tesla

Nikola Tesla





Who Was Nikola Tesla?

Nikola Tesla was an engineer and scientist known for designing the alternating-current (AC) electric system, which is the predominant electrical system used across the world today. He also created the "Tesla coil," which is still used in radio technology. 
Born in modern-day Croatia, Tesla came to the United States in 1884 and briefly worked with Thomas Edison before the two parted ways. He sold several patent rights, including those to his AC machinery, to George Westinghouse.

Early Life

Tesla was born in Smiljan, Croatia, on July 10, 1856.
Tesla was one of five children, including siblings Dane, Angelina, Milka and Marica. Tesla's interest in electrical invention was spurred by his mother, Djuka Mandic, who invented small household appliances in her spare time while her son was growing up.
Tesla's father, Milutin Tesla, was a Serbian orthodox priest and a writer, and he pushed for his son to join the priesthood. But Nikola's interests lay squarely in the sciences.

Education

After studying at the Realschule, Karlstadt (later renamed the Johann-Rudolph-Glauber Realschule Karlstadt) in Germany; the Polytechnic Institute in Graz, Austria; and the University of Prague during the 1870s, Tesla moved to Budapest, where for a time he worked at the Central Telephone Exchange.
It was while in Budapest that the idea for the induction motor first came to Tesla, but after several years of trying to gain interest in his invention, at age 28 Tesla decided to leave Europe for America.

Nikola Tesla vs. Thomas Edison

In 1884 Tesla arrived in the United States with little more than the clothes on his back and a letter of introduction to famed inventor and business mogul Thomas Edison, whose DC-based electrical works were fast becoming the standard in the country.
Edison hired Tesla, and the two men were soon working tirelessly alongside each other, making improvements to Edison's inventions.
Several months later, the two parted ways due to a conflicting business-scientific relationship, attributed by historians to their incredibly different personalities: While Edison was a power figure who focused on marketing and financial success, Tesla was commercially out-of-touch and somewhat vulnerable.

First Solo Venture

In 1885, Tesla received funding for the Tesla Electric Light Company and was tasked by his investors to develop improved arc lighting. After successfully doing so, however, Tesla was forced out of the venture and for a time had to work as a manual laborer in order to survive.
His luck would change two years later when he received funding for his new Tesla Electric Company.

Inventions

Throughout his career, Tesla discovered, designed and developed ideas for a number of important inventions — most of which were officially patented by other inventors — including dynamos (electrical generators similar to batteries) and the induction motor. 
He was also a pioneer in the discovery of radar technology, X-ray technology, remote control and the rotating magnetic field — the basis of most AC machinery. Tesla is most well-known for his contributions in AC electricity and for the Tesla coil.

AC Electrical System

Tesla designed the alternating-current (AC) electrical system, which would quickly become the preeminent power system of the 20th century and has remained the worldwide standard ever since. In 1887, Tesla found funding for his new Tesla Electric Company, and by the end of the year, he had successfully filed several patents for AC-based inventions.
Tesla's AC system soon caught the attention of American engineer and businessman George Westinghouse, who was seeking a solution to supplying the nation with long-distance power. Convinced that Tesla's inventions would help him achieve this, in 1888 he purchased his patents for $60,000 in cash and stock in the Westinghouse Corporation.
As interest in an AC system grew, Tesla and Westinghouse were put in direct competition with Thomas Edison, who was intent on selling his direct-current (DC) system to the nation. A negative press campaign was soon waged by Edison, in an attempt to undermine interest in AC power. 
Unfortunately for Edison, the Westinghouse Corporation was chosen to supply the lighting at the 1893 World's Columbian Exposition in Chicago, and Tesla conducted demonstrations of his AC system there.

Hydroelectric Power Plant

In 1895, Tesla designed what was among the first AC hydroelectric power plants in the United States, at Niagara Falls. 
The following year, it was used to power the city of Buffalo, New York — a feat that was highly publicized throughout the world and helped further AC electricity’s path to becoming the world’s power system.

Tesla Coil

In the late 19th century, Tesla patented the Tesla coil, which laid the foundation for wireless technologies and is still used in radio technology today. The heart of an electrical circuit, the Tesla coil is an inductor used in many early radio transmission antennas. 
The coil works with a capacitor to resonate current and voltage from a power source across the circuit. Tesla himself used his coil to study fluorescence, x-rays, radio, wireless power and electromagnetism in the earth and its atmosphere. 

Free Energy

Having become obsessed with the wireless transmission of energy, around 1900 Tesla set to work on his boldest project yet: to build a global, wireless communication system — to be transmitted through a large electrical tower — for sharing information and providing free energy throughout the world. 
With funding from a group of investors that included financial giant J. P. Morgan, in 1901 Tesla began work on the free energy project in earnest, designing and building a lab with a power plant and a massive transmission tower on a site on Long Island, New York, that became known as Wardenclyffe.
However, doubts arose among his investors about the plausibility of Tesla's system. As his rival, Guglielmo Marconi — with the financial support of Andrew Carnegie and Thomas Edison — continued to make great advances with his own radio technologies, Tesla had no choice but to abandon the project. 
The Wardenclyffe staff was laid off in 1906, and by 1915 the site had fallen into foreclosure. Two years later Tesla declared bankruptcy and the tower was dismantled and sold for scrap to help pay the debts he had accrued.

Death Ray

After suffering a nervous breakdown following the closure of his free energy project, Tesla eventually returned to work, primarily as a consultant. 
But as time went on, his ideas became progressively more outlandish and impractical. He grew increasingly eccentric, devoting much of his time to the care of wild pigeons in the parks of New York City
Tesla even drew the attention of the FBI with his talk of building a powerful "death ray," which had received some interest from the Soviet Union during World War II.

How Did Nikola Tesla Die?

Poor and reclusive, Tesla died of coronary thrombosis on January 7, 1943, at the age of 86 in New York City, where he had lived for nearly 60 years. 
However, the legacy of the work Tesla left behind him lives on to this day. In 1994, a street sign identifying "Nikola Tesla Corner" was installed near the site of his former New York City laboratory, at the intersection of 40th Street and 6th Avenue.

Movies on Tesla

Several movies have highlighted Tesla's life and famous works, most notably:
  • The Secret of Nikola Tesla, a 1980 biographical film starring Orson Welles as J. P. Morgan.
  • Nikola Tesla, The Genius Who Lit the World, a 1994 documentary produced by the Tesla Memorial Society and the Nikola Tesla Museum in Belgrade, Serbia.
  • The Prestige, a 2006 fictional film about two magicians directed by Christopher Nolan, with rock star David Bowie portraying Tesla.

Tesla Motors & the Electric Car

In 2003, a group of engineers founded Tesla Motors, a car company named after Tesla dedicated to building the first fully electric-powered car. Entrepreneur and engineer Elon Musk contributed over $30 million to Tesla in 2004 and serves as the company’s co-founder CEO.
In 2008, Tesla unveiled its first electric car, the Roadster. A high-performance sports vehicle, the Roadster helped changed the perception of what electric cars could be. In 2014, Tesla launched the Model S, a lower-priced model that, in 2017, set the Motor Trend world record for 0 to 60 miles per hour acceleration at 2.28 seconds.
Tesla’s designs showed that an electric car could have the same performance as gasoline-powered sports car brands like Porsche and Lamborghini.

Tesla Science Center and Wardenclyffe

Since Tesla's original forfeiture of his free energy project, ownership of the Wardenclyffe property has passed through numerous hands. Several attempts have been made to preserve it, but in 1967, 1976 and 1994 efforts to have it declared a national historic site failed. 
Then, in 2008, a group called the Tesla Science Center (TSC) was formed with the intention of purchasing the property and turning it into a museum dedicated to the inventor's work.
In 2009, the Wardenclyffe site went on the market for nearly $1.6 million, and for the next several years, the TSC worked diligently to raise funds for its purchase. In 2012, public interest in the project peaked when Matthew Inman of TheOatmeal.com collaborated with the TSC in an Internet fundraising effort, ultimately receiving enough contributions to acquire the site in May 2013. 
Work on its restoration is still in progress, and the site is closed to the public “for the foreseeable future” for reasons of safety and preservation, according to the Tesla Science Center.

https://player.biography.com/player/biography.html?tpid=1203633219676&autoplay=false#

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