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Spectrum2017
A spectrum (: spectra or spectrums) is a set of related ideas, objects, or properties whose features overlap such that they blend to form a continuum. The word ''spectrum'' was first used scientifically in optics to describe the rainbow of colors in visible light after passing through a prism. In the optical spectrum, light wavelength is viewed as continuous, and spectral colors are seen to blend into one another smoothly when organized in order of their corresponding wavelengths. As scientific understanding of light advanced, the term came to apply to the entire electromagnetic spectrum, including radiation not visible to the human eye. ''Spectrum'' has since been applied by analogy to topics outside optics. Thus, one might talk about the " spectrum of political opinion", or the "spectrum of activity" of a drug, or the "autism spectrum". In these uses, values within a spectrum may not be associated with precisely quantifiable numbers or definitions. Such uses imply a broad r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rainbow Above Kaviskis Lake, Lithuania
A rainbow is an optical phenomenon caused by refraction, internal reflection and dispersion (optics), dispersion of light in water droplets resulting in a continuous visible spectrum, spectrum of light appearing in the sky. The rainbow takes the form of a multicoloured circular arc (geometry), arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the Sun. Rainbows can be caused by many forms of airborne water. These include not only rain, but also mist, spray, and airborne dew. Rainbows can be full circles. However, the observer normally sees only an arc formed by illuminated droplets above the ground, and centered on a line from the Sun to the observer's eye. In a primary rainbow, the arc shows red on the outer part and violet on the inner side. This rainbow is caused by light being refracted when entering a droplet of water, then reflected inside on the back of the droplet and refracted again when leaving it. In a double rainbow, a second ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Witchcraft
Witchcraft is the use of Magic (supernatural), magic by a person called a witch. Traditionally, "witchcraft" means the use of magic to inflict supernatural harm or misfortune on others, and this remains the most common and widespread meaning. According to ''Encyclopedia Britannica'', "Witchcraft thus defined exists more in the imagination", but it "has constituted for many cultures a viable explanation of evil in the world". The belief in witches has been found throughout history in a great number of societies worldwide. Most of these societies have used Apotropaic magic, protective magic or counter-magic against witchcraft, and have shunned, banished, imprisoned, physically punished or killed alleged witches. Anthropologists use the term "witchcraft" for similar beliefs about harmful occult practices in different cultures, and these societies often use the term when speaking in English. Belief in witchcraft as malevolent magic is attested from #Ancient Mesopotamian religion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ampicillin
Ampicillin is an antibiotic belonging to the aminopenicillin class of the penicillin family. The drug is used to prevent and treat several bacterial infections, such as respiratory tract infections, urinary tract infections, meningitis, salmonellosis, and endocarditis. It may also be used to prevent group B streptococcal infection in newborns. It is used by mouth, by injection into a muscle, or intravenously. Common side effects include rash, nausea, and diarrhea. It should not be used in people who are allergic to penicillin. Serious side effects may include ''Clostridioides difficile'' colitis or anaphylaxis. While usable in those with kidney problems, the dose may need to be decreased. Its use during pregnancy and breastfeeding appears to be generally safe. Ampicillin was discovered in 1958 and came into commercial use in 1961. It is on the World Health Organization's List of Essential Medicines. The World Health Organization classifies ampicillin as critical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Narrow-spectrum Antibiotic
A narrow-spectrum antibiotic is an antibiotic that is only able to kill or inhibit limited species of bacteria. Examples of narrow-spectrum antibiotics include fidaxomicin and sarecycline Sarecycline, sold under the brand name Seysara, is a narrow-spectrum tetracycline-derived antibiotic medication. It is specifically designed for the treatment of acne, and was approved by the FDA in October 2018 for the treatment of inflammat .... Advantages * Narrow-spectrum antibiotic allow to kill or inhibit only those bacteria species that are unwanted (i.e. causing disease). As such, it leaves most of the beneficial bacteria unaffected, hence minimizing the collateral damage on the microbiota. * Low propensity for bacterial resistance development. Disadvantages Often, the exact species of bacteria causing the illness is unknown, in which case narrow-spectrum antibiotics can't be used, and broad-spectrum antibiotics are used instead. To know the exact species of bacteria causing the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broad-spectrum Antibiotic
A broad-antimicrobial spectrum, spectrum antibiotic is an antibiotic that acts on the two major bacterial groups, Gram-positive and Gram-negative, or any antibiotic that acts against a wide range of disease-causing bacteria. These medications are used when a bacterial infection is suspected but the group of bacteria is unknown (also called empiric therapy) or when infection with multiple groups of bacteria is suspected. This is in contrast to a narrow-spectrum antibiotic, which is effective against only a specific group of bacteria. Although powerful, broad-spectrum antibiotics pose specific risks, particularly the disruption of native, normal bacteria and the development of antimicrobial resistance. An example of a commonly used broad-spectrum antibiotic is ampicillin. Bacterial targets Antibiotics are often grouped by their ability to act on different bacterial groups. Although bacteria are biologically classified using Bacterial taxonomy, taxonomy, disease-causing bacteria hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibiotic
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy, treatment and antibiotic prophylaxis, prevention of such infections. They may either bactericide, kill or bacteriostatic agent, inhibit the growth of bacteria. A limited number of antibiotics also possess antiprotozoal activity. Antibiotics are not effective against viruses such as the ones which cause the common cold or influenza. Drugs which inhibit growth of viruses are termed antiviral drugs or antivirals. Antibiotics are also not effective against fungi. Drugs which inhibit growth of fungi are called antifungal drugs. Sometimes, the term ''antibiotic''—literally "opposing life", from the Greek language, Greek roots ἀντι ''anti'', "against" and βίος ''bios'', "life"—is broadly used to refer to any substance used against ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Analysis
Analytical chemistry studies and uses instruments and methods to separate, identify, and quantify matter. In practice, separation, identification or quantification may constitute the entire analysis or be combined with another method. Separation isolates analytes. Qualitative analysis identifies analytes, while quantitative analysis determines the numerical amount or concentration. Analytical chemistry consists of classical, wet chemical methods and modern analytical techniques. Classical qualitative methods use separations such as precipitation, extraction, and distillation. Identification may be based on differences in color, odor, melting point, boiling point, solubility, radioactivity or reactivity. Classical quantitative analysis uses mass or volume changes to quantify amount. Instrumental methods may be used to separate samples using chromatography, electrophoresis or field flow fractionation. Then qualitative and quantitative analysis can be performed, often wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectroscopy
Spectroscopy is the field of study that measures and interprets electromagnetic spectra. In narrower contexts, spectroscopy is the precise study of color as generalized from visible light to all bands of the electromagnetic spectrum. Spectroscopy, primarily in the electromagnetic spectrum, is a fundamental exploratory tool in the fields of astronomy, chemistry, materials science, and physics, allowing the composition, physical structure and electronic structure of matter to be investigated at the atomic, molecular and macro scale, and over astronomical distances. Historically, spectroscopy originated as the study of the wavelength dependence of the absorption by gas phase matter of visible light dispersed by a prism. Current applications of spectroscopy include biomedical spectroscopy in the areas of tissue analysis and medical imaging. Matter waves and acoustic waves can also be considered forms of radiative energy, and recently gravitational waves have been associa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectrometer
A spectrometer () is a scientific instrument used to separate and measure Spectrum, spectral components of a physical phenomenon. Spectrometer is a broad term often used to describe instruments that measure a continuous variable of a phenomenon where the spectral components are somehow mixed. In visible light a spectrometer can separate white light and measure individual narrow bands of color, called a spectrum. A mass spectrometer measures the spectrum of the masses of the atoms or molecules present in a gas. The first spectrometers were used to split light into an array of separate colors. Spectrometers were History_of_spectroscopy, developed in early studies of physics, astronomy, and chemistry. The capability of spectroscopy to determine Analytical_chemistry#Spectroscopy, chemical composition drove its advancement and continues to be one of its primary uses. Spectrometers are used in Astronomical spectroscopy, astronomy to analyze the chemical composition of Astronomical_spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
On Vision And Colors
''On Vision and Colors'' (originally translated as ''On Vision and Colours''; ) is a treatise by Arthur Schopenhauer that was published in May 1816 when the author was 28 years old. Schopenhauer had extensive discussions with Johann Wolfgang von Goethe about the poet's ''Theory of Colours'' of 1810, in the months around the turn of the years 1813 and 1814, and initially shared Goethe's views.Karl Robert Mandelkow, Bodo Morawe: Goethes Briefe (''Goethe's Letters''). 1. edition. Vol. 3: Briefe der Jahre 1805-1821 (''Letters of the years 1805-1821''). ''Christian Wegner'' publishers, Hamburg 1965, p. 639. "Vom November 1813 bis zum Mai 1814 sind sie in Weimar sehr häufig zusammengewesen. (...) In den Mittelpunkt der Diskussionen rückte schließlich die Goethesche ''Farbenlehre''. Schopenhauer teilte prinzipiell die Ansichten des Dichters, wich jedoch in gewissen Einzelheiten von ihnen ab." (''"From November 1813 till May 1814, they were together very often in Weimar. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthur Schopenhauer
Arthur Schopenhauer ( ; ; 22 February 1788 – 21 September 1860) was a German philosopher. He is known for his 1818 work ''The World as Will and Representation'' (expanded in 1844), which characterizes the Phenomenon, phenomenal world as the manifestation of a blind and irrational noumenon, noumenal Will (philosophy), will. Building on the transcendental idealism of Immanuel Kant, Schopenhauer developed an atheistic metaphysical and ethical system that rejected the contemporaneous ideas of German idealism. Schopenhauer was among the first philosophers in the Western philosophy, Western tradition to share and affirm significant tenets of Indian philosophy, such as asceticism, denial of the self (philosophy), self, and the notion of the Maya (religion), world-as-appearance. His work has been described as an exemplary manifestation of philosophical pessimism. Though his work failed to garner substantial attention during his lifetime, he had a posthumous impact across various ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theory Of Colours (book)
''Theory of Colours'' () is a book by Johann Wolfgang von Goethe about the poet's views on the nature of colours and how they are perceived by humans. It was published in German in 1810 and in English in 1840. The book contains detailed descriptions of phenomena such as Complementary colours, coloured shadows, refraction, and chromatic aberration. The book is a successor to two short essays titled "Contributions to Optics" (). The work originated in Goethe's occupation with painting and primarily had its influence in the arts, with painters such as (Philipp Otto Runge, J. M. W. Turner, the Pre-Raphaelites, Hilma af Klint, and Wassily Kandinsky). Although Goethe's work was rejected by some physicists, a number of philosophers and physicists have concerned themselves with it, including Thomas Johann Seebeck, Arthur Schopenhauer (see: ''On Vision and Colors''), Hermann von Helmholtz, Ludwig Wittgenstein, Werner Heisenberg, Kurt Gödel, and Mitchell Feigenbaum. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
