The year 30 BC was either a common year starting on Wednesday, Thursday or Friday or a leap year starting on Thursday. At the time, it was known as the Year of the Consulship of Octavian and Crassus.
January 29
Economy
An economy is a system of making and trading things of value. It is usually divided into goods (physical things) and services (things done by people). It assumes there is medium of exchange, which in the modern world is a system of finance. This makes trade possible. The alternative systems of barter – exists only on a very small scale.
To better understand how the economy works, it can be discussed in three sections. These are:
The term 'real economy' is sometimes used to mean the part of the economy concerned with goods and services. This is contrasted with the 'paper economy', the financial side of the economy, which buys and sells on the financial markets.
The word 'economy' comes from the Greek word "οἰκονόμος". This means "person who manages the house".
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September 19
September 9
Engine
An engine, or motor, is a machine used to change energy into movement that can be used. The energy can be in any form. Common forms of energy used in engines are electricity, chemical (such as petrol or diesel) or heat. When a chemical is used to produce energy it is known as "fuel".
In past centuries "motor" and "engine" meant very different things. A motor was made to move something such as a vehicle. This meaning is still often used. Sometimes a thing is called an engine if it creates mechanical energy from heat, and a motor if it creates mechanical energy from other kinds of energy, like electricity. Typical "engines" in this meaning are steam engine and internal combustion engine, while typical "motors" are electric motor and hydraulic motor. And sometimes the two words mean the same thing.
"Engine" was originally a term for any mechanical device that converts force into motion. Hence, pre-industrial weapons such as catapults, trebuchets and battering rams were called "siege engines". The word "gin," as in "cotton gin", is short for "engine." The word derives from Old French "engin", from the Latin "ingenium", which is also the root of the word "ingenious". Most mechanical devices invented during the industrial revolution were described as engines—the steam engine being a notable example.
Early kinds of engine used heat that was outside of the engine itself to heat up a gas to a high pressure. This was usually steam and the engines are called steam engines. The steam was piped to the engine where it pushed on pistons to bring about motion. These engines were commonly used in old factories, boats and trains.
Most cars use a chemical engine that burns fuel inside it. This is called an internal combustion engine. There are many different types of internal combustion engine. They can be grouped by fuel, cycle and configuration. Common fuel types for internal combustion engines are petrol, diesel, autogas and alcohol. There are many other types of fuels.
There are 3 different types of cycle. 2-stroke engines produce power once every turn of the engine. 4-stroke engines cylinders make power once every two turns of the engine. 6-stroke engines cylinders make power twice in every six turns of the engine.
There are lots of different configurations of piston engines. Their cylinders have pistons in them and a crankshaft. Any number of cylinders can be used but 1, 2, 3, 4, 6, 8, 10 and 12 are common. The cylinders can be arranged in many ways, in a straight line, at an angle to each other or in a circle.
A Wankel engine has no cylinders and uses a triangle shaped rotor spinning in an oval housing which mimics the movement of a piston.
Hot gas can also be made to push a turbine around rather like the way the wind turns a windmill. Most electric power stations use big steam turbines. Others use water or wind turbines. Smaller turbines called gas turbines are used for internal combustion engines, such as the jet engines used in aircraft.
A rocket causes movement by shooting jets of gas very fast out of a nozzle. The gas may have been stored under pressure or be a chemical fuel that burns to make a very hot gas. Although they are very simple, rockets are the most powerful engines we know how to make. They will work in space where there is nothing to push against.
Electric motors do not use a fuel. The energy is supplied to them by electricity carried along wires. The energy may come from a fuel being burnt somewhere else a long way off. The electricity is used to make powerful magnets inside the motor switch on and off at the right time to turn the shaft of the motor.
"Electric engine" is not a motor, but a railway locomotive which runs on electricity.
Belarus
Belarus (officially called Republic of Belarus) is a country in Eastern Europe. About nine million people live there. Its capital is Minsk. It was part of the Soviet Union until 1991. The president of Belarus has been Alexander Lukashenko since 1994. It is bordered by Russia, Ukraine, Poland, Lithuania and Latvia. Over forty percent of its is forested.
The State is a member of the UN, the CIS, Collective Security Treaty Organization, the Eurasian Economic Community, the Union State of Russia and Belarus (from 2 April 1997), as well as a member of other international organizations.
Until the 20th century, the lands of modern-day Belarus belonged to several countries. These included the Principality of Polotsk, the Grand Duchy of Lithuania, the Polish–Lithuanian Commonwealth, and the Russian Empire. After the Russian Revolution, Belarus became part of the Soviet Union. It was renamed the Byelorussian Soviet Socialist Republic (BSSR). The borders of Belarus took their modern shape in 1939. Some lands of the Second Polish Republic were added into it after the Soviet invasion of Poland. The nation and its territory were devastated in World War II. Belarus lost about a third of its population and more than half of its economic resources. In 1945 the Belorussian SSR became a founding member of the United Nations, along with the Soviet Union and the Ukrainian SSR.
The parliament of the republic declared the sovereignty of Belarus on 1990. During the dissolution of the Soviet Union, Belarus became independent on 1991.
Over 70% of Belarus's population of 9.49 million live in the urban areas. More than 80% of the population are ethnic Belarusians. Most of the rest are Russians, Poles and Ukrainians. The country has two official languages: Belarusian and Russian. The main religion in the country is Russian Orthodox Christianity. The second most popular, Roman Catholicism, has a much smaller following.
Both Homo erectus and Neanderthal remains have been found in the region. From 5,000 to 2,000 BCE, Bandkeramik cultures lived here. Cimmerians were in the area by 1,000 BCE. By 500 BCE, Slavs moved in. The Huns and Avars came through around 400–600 CE. They were unable to move the Slavs.
The region that is now Belarus was first settled by Slavic tribes in the 6th century. They came into contact with the Varangians, who were bands of Scandinavian warriors and traders. They formed Kievan Rus' in 862.
When Kievan Rus' ruler Yaroslav I the Wise died, the state split. Later some were added into the Grand Duchy of Lithuania. Lithuania made a union with Poland. The union ended in 1795. The land of Belarus went to the Russian Empire. The land stayed with Russia until going to the German Empire during World War I.