Germacranolides are a group of natural chemical compounds classified as sesquiterpene lactones. They are found in a variety of plant sources. [1]
Germacranolides are a group of natural chemical compounds classified as sesquiterpene lactones. They are found in a variety of plant sources. [1]
A disaster is a serious problem that happens over a period of time and causes harm to people, things, economies, or the environment that the affected community or society cannot handle it on its own. In theory, natural disasters are those caused by natural hazards, whereas human-made disasters are those caused by human hazards. However, in modern times, the divide between natural, human-made or human-accelerated disasters is more and more difficult to draw. In fact, all disasters can be seen as human-made, due to human failure to introduce appropriate emergency management measures.
An integer is the number zero (0), a positive natural number or a negative integer. The negative numbers are the additive inverses of the corresponding positive numbers. The set of all integers is often denoted by the boldface Z or blackboard bold .
In music theory, the minor scale has three scale patterns – the natural minor scale, the harmonic minor scale, and the melodic minor scale – mirroring the major scale, with its harmonic and melodic forms.
Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations. Charles Darwin popularised the term "natural selection", contrasting it with artificial selection, which is intentional, whereas natural selection is not.
In mathematics, the natural numbers are the numbers 0, 1, 2, 3, etc., possibly excluding 0.[under discussion] Some define the natural numbers as the non-negative integers0, 1, 2, 3, ..., while others define them as the positive integers1, 2, 3, .... Some authors acknowledge both definitions whenever convenient. Some texts define the whole numbers as the natural numbers together with zero, excluding zero from the natural numbers, while in other writings, the whole numbers refer to all of the integers. The counting numbers refer to the natural numbers in common language, particularly in primary school education, and are similarly ambiguous although typically exclude zero.
The natural logarithm of a number is its logarithm to the base of the mathematical constant e, which is an irrational and transcendental number approximately equal to 2.718281828459. The natural logarithm of x is generally written as ln x, logex, or sometimes, if the base e is implicit, simply log x. Parentheses are sometimes added for clarity, giving ln(x), loge(x), or log(x). This is done particularly when the argument to the logarithm is not a single symbol, so as to prevent ambiguity.
Natural resources are resources that are drawn from nature and used with few modifications. This includes the sources of valued characteristics such as commercial and industrial use, aesthetic value, scientific interest, and cultural value. On Earth, it includes sunlight, atmosphere, water, land, all minerals along with all vegetation, and wildlife.
Natural law is a system of law based on a close observation of natural order and human nature, from which values, thought by the proponents of this concept to be intrinsic to human nature, can be deduced and applied independently of positive law. According to the theory of law called jusnaturalism, all people have inherent rights, conferred not by act of legislation but by "God, nature, or reason." Natural law theory can also refer to "theories of ethics, theories of politics, theories of civil law, and theories of religious morality."
Natural gas is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane (97%) in addition to various smaller amounts of other higher alkanes. Traces of carbon dioxide, nitrogen, hydrogen sulfide, and helium are also usually present. Methane is colorless and odorless, and the second largest greenhouse gas contributor to global climate change after carbon dioxide. Because natural gas is odorless, odorizers such as mercaptan are commonly added to it for safety so that leaks can be readily detected.
Science is a rigorous, systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the world. Modern science is typically divided into three major branches: the natural sciences, which study the physical world; the social sciences, which study individuals and societies; and the formal sciences, which study formal systems, governed by axioms and rules. There is disagreement whether the formal sciences are science disciplines, as they do not rely on empirical evidence. Applied sciences are disciplines that use scientific knowledge for practical purposes, such as in engineering and medicine.
Rubber, also called India rubber, latex, Amazonian rubber, caucho, or caoutchouc, as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Thailand, Malaysia, Indonesia, and Cambodia are four of the leading rubber producers.
Natural science is one of the branches of science concerned with the description, understanding and prediction of natural phenomena, based on empirical evidence from observation and experimentation. Mechanisms such as peer review and repeatability of findings are used to try to ensure the validity of scientific advances.
World Heritage Sites are landmarks and areas with legal protection by an international convention administered by UNESCO for having cultural, historical, or scientific significance. The sites are judged to contain "cultural and natural heritage around the world considered to be of outstanding value to humanity".
A natural disaster is the highly harmful impact on a society or community following a natural hazard event. Examples of natural hazard events include floods, droughts, earthquakes, tropical cyclones, volcanic activity, wildfires. A natural disaster can cause loss of life or damage property, and typically leaves economic damage in its wake. The severity of the damage depends on the population's disaster preparedness and on the existing infrastructure. Scholars have been saying that the term natural disaster is unsuitable and should be abandoned. Instead, the simpler term disaster could be used, while also specifying the category of hazard. A disaster is a result of a natural or human-made hazard impacting a vulnerable community. It is the combination of the hazard along with exposure of a vulnerable society that results in a disaster.
Sir David Frederick Attenborough is a British broadcaster, biologist, natural historian, and writer. He is best known for writing and presenting, in conjunction with the BBC Natural History Unit, the nine natural history documentary series forming the Life collection, a comprehensive survey of animal and plant life on Earth.
The Natural History Museum in London is a museum that exhibits a vast range of specimens from various segments of natural history. It is one of three major museums on Exhibition Road in South Kensington, the others being the Science Museum and the Victoria and Albert Museum. The Natural History Museum's main frontage, however, is on Cromwell Road.
The natural environment or natural world encompasses all living and non-living things occurring naturally, meaning in this case not artificial. The term is most often applied to Earth or some parts of Earth. This environment encompasses the interaction of all living species, climate, weather and natural resources that affect human survival and economic activity. The concept of the natural environment can be distinguished as components:
Liquefied natural gas (LNG) is natural gas (predominantly methane, CH4, with some mixture of ethane, C2H6) that has been cooled down to liquid form for ease and safety of non-pressurized storage or transport. It takes up about 1/600th the volume of natural gas in the gaseous state at standard conditions for temperature and pressure.
Charles Robert Darwin was an English naturalist, geologist and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended from a common ancestor is now generally accepted and considered a fundamental concept in science. In a joint publication with Alfred Russel Wallace, he introduced his scientific theory that this branching pattern of evolution resulted from a process he called natural selection, in which the struggle for existence has a similar effect to the artificial selection involved in selective breeding. Darwin has been described as one of the most influential figures in human history and was honoured by burial in Westminster Abbey.
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