Gram

The gram (alternative spelling: gramme;[1] SI unit symbol: g) (Latin gramma, from Greek γράμμα, grámma) is a metric system unit of mass.

Originally defined as "the absolute weight of a volume of pure water equal to the cube of the hundredth part of a metre [1 cm3], and at the temperature of melting ice"[2] (later at 4 °C, the temperature of maximum density of water). However, in a reversal of reference and defined units, a gram is now defined as one thousandth of the SI base unit, the kilogram, or 1×10−3 kg, which itself is now defined by the International Bureau of Weights and Measures, not in terms of grams, but by "the amount of electricity needed to counteract its force"[3]

Gram
Gram (pen cap on scale)
The mass of this pen cap is about 1 gram
General information
Unit systemSI derived unit and CGS base unit
Unit ofMass
Symbolg 
Conversions
1 g in ...... is equal to ...
   SI base units   10−3 kilograms
   CGS units   1 gram
   Imperial units
U.S. customary
   0.0353 ounces

Official SI symbol

The only unit symbol for gram that is recognised by the International System of Units (SI) is "g" following the numeric value with a space, as in "640 g" to stand for "640 grams" in the English language. The SI does not support the use of abbreviations such as "gr" (which is the symbol for grains),[4]:C-19 "gm" ("g⋅m" is the SI symbol for gram-metre) or "Gm" (the SI symbol for gigametre).

History

The word gramme was adopted by the French National Convention in its 1795 decree revising the metric system as replacing the gravet introduced in 1793. Its definition remained that of the weight (poids) of a cubic centimetre of water.[5][6] French gramme was taken from the Late Latin term gramma. This word—ultimately from Greek γράμμα (grámma), "letter"—had adopted a specialised meaning in Late Antiquity of "one twenty-fourth part of an ounce" (two oboli),[7] corresponding to about 1.14 modern grams. This use of the term is found in the carmen de ponderibus et mensuris ("poem about weights and measures") composed around 400 AD.[a] There is also evidence that the Greek γράμμα was used in the same sense at around the same time, in the 4th century, and survived in this sense into Medieval Greek,[9] while the Latin term did not remain current in Medieval Latin and was recovered in Renaissance scholarship.[b]

The gram was the fundamental unit of mass in the 19th-century centimetre–gram–second system of units (CGS). The CGS system co-existed with the MKS system of units, first proposed in 1901, during much of the 20th century, but the gram has been displaced by the kilogram as the fundamental unit for mass when the MKS system was chosen for the SI base units in 1960.

Uses

The gram is today the most widely used unit of measurement for non-liquid ingredients in cooking and grocery shopping worldwide.

Most standards and legal requirements for nutrition labels on food products require relative contents to be stated per 100 g of the product, such that the resulting figure can also be read as a percentage by weight.

Conversion factors

  • 1 gram (g) = 15.4323583529 grains (gr)
  • 1 grain (gr) = 0.06479891 grams (g)
  • 1 avoirdupois ounce (oz) = 28.349523125 grams (g)
  • 1 troy ounce (ozt) = 31.1034768 grams (g)
  • 100 grams (g) = 3.527396195 ounces
  • 1 gram (g) = 5 carats (ct)
  • 1 gram (g) = 8.98755179×1013 joules (J) (by mass–energy equivalence)
  • 1 undecimogramme = 1 "eleventh-gram" = 10−11 grams in the historic quadrant–eleventh-gram–second system (QES system) a.k.a. hebdometre–undecimogramme–second system (HUS system) (HUS system) [10]
  • 500 grams (g) = 1 Jin in the Chinese units of measurement.

Comparisons

See also

Notes

  1. ^ The date and authorship of this Late Latin didactic poem are both uncertain; it was attributed to Priscian but is now attributed to Rem(m)ius Favinus/Flav(in)us.[8] The poem's title is reflected in the French phrase poids et mesures ("weights and mesures") in the title of the 1795 National Convention decree, Décret relatif aux poids et aux mesures that introduced the gram, and indirectly in the name of the General Conference on Weights and Measures responsible for the modern definition of the metric units.
  2. ^ In the Renaissance, the carmen de ponderibus et mensuris was received as a work of the 1st-century grammarian Remmius Palaemon edited in 1528 by Johann Setzer of Hagenau, together with works by Celsius, Priscian and Johannes Caesarius; Aurelij Cornelij Celsi, De re medica, libri octo eruditissimi. Q. Sereni Samonici Praecepta medica, uersibus hexametris. Q. Rhemnij Fannij Palaemonis, De ponderibus [et] mensuris, liber rarus [et] utilissimus

References

  1. ^ "Weights and Measures Act 1985 (c. 72)". The UK Statute Law Database. Office of Public Sector Information. Archived from the original on 2008-09-12. Retrieved 2011-01-26. §92.
  2. ^ Décret relatif aux poids et aux mesures Archived 2013-05-10 at WebCite, 1795
  3. ^ "Kilogram gets a new definition". BBC News. Retrieved 16 November 2018.
  4. ^ National Institute of Standards and Technology (October 2011). Butcher, Tina; Cook, Steve; Crown, Linda et al. eds. "Appendix C – General Tables of Units of Measurement" Archived 2016-06-17 at the Wayback Machine. (PDF). Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices Archived 2016-08-23 at the Wayback Machine.. NIST Handbook. 44 (2012 ed.). Washington, D.C.: U.S. Department of Commerce, Technology Administration, National Institute of Standards and Technology. ISSN 0271-4027. OCLC OCLC 58927093. Retrieved 30 June 2012.
  5. ^ "Décret relatif aux poids et aux mesures du 18 germinal an 3 (7 avril 1795)" [Decree of 18 Germinal, year III (April 7, 1795) regarding weights and measures]. Grandes lois de la République (in French). Digithèque de matériaux juridiques et politiques, Université de Perpignan. Archived from the original on May 10, 2013. Retrieved November 3, 2011.
  6. ^ Convention nationale, décret du 1er août 1793, ed. Duvergier, Collection complète des lois, décrets, ordonnances, règlemens avis du Conseil d'état, publiée sur les éditions officielles du Louvre, vol. 6 (2nd ed. 1834), p. 70 Archived 2015-04-02 at the Wayback Machine.. The metre (mètre) on which this definition depends was itself defined as the ten-millionth part of a quarter of Earth's meridian, given in traditional units as 3 pieds, 11.44 lignes (a ligne being the 12th part of an pouce (inch), or the 144th part of a pied.
  7. ^ Charlton T. Lewis, Charles Short, A Latin Dictionary s.v. "gramma" Archived 2015-07-17 at the Wayback Machine., 1879
  8. ^ Knorr, Wilbur R. (1996). "Carmen de ponderibus et mensuris". In Hornblower, Simon; Spawforth, Antony. The Oxford Classical Dictionary (3rd ed.). Oxford: Oxford University Press. p. 292. ISBN 019866172X.
  9. ^ Henry George Liddell. Robert Scott. A Greek-English Lexicon (revised and augmented edition, Oxford, 1940) s.v. γράμμα Archived 2015-07-17 at the Wayback Machine., citing the 10th-century work Geoponica and a 4th-century papyrus edited in L. Mitteis, Griechische Urkunden der Papyrussammlung zu Leipzig, vol. i (1906), 62 ii 27.
  10. ^ "System of Measurement Units - Engineering and Technology History Wiki". ethw.org. Archived from the original on 29 April 2018. Retrieved 29 April 2018.
  11. ^ "Circulating Coin Designs". Japan Mint. Archived from the original on 18 September 2009. Retrieved 7 March 2010.

External links

Aerobic organism

An aerobic organism or aerobe is an organism that can survive and grow in an oxygenated environment. In contrast, an anaerobic organism (anaerobe) is any organism that does not require oxygen for growth. Some anaerobes react negatively or even die if oxygen is present.

Bacilli

Bacilli is a taxonomic class of bacteria that includes two orders, Bacillales and Lactobacillales, which contain several well-known pathogens such as Bacillus anthracis (the cause of anthrax). Bacilli are almost exclusively gram-positive bacteria.

Calorie

A calorie or calory (archaic) is a unit of energy. Various definitions exist but fall into two broad categories. The first, the small calorie (symbol: cal), is defined as the amount of heat energy needed to raise the temperature of one gram of water by one degree Celsius at a pressure of one atmosphere. The second, the large calorie or kilocalorie (symbols: Cal, kcal), also known as the food calorie and similar names, is defined as the heat energy required to raise the temperature of one kilogram (rather than a gram) of water by one degree Celsius. It is equal to 1,000 small calories.Although these units relate to the metric system, all of them have been considered obsolete in science since the adoption of the SI system. The unit of energy in the International System of Units is the joule. One small calorie is approximately 4.2 joules (so one large calorie is about 4.2 kilojoules). The factor used to convert calories to joules at a given temperature is numerically equivalent to the specific heat capacity of water expressed in joules per kelvin per gram (or per kilogram, for kilocalories). The precise conversion factor depends on the definition adopted.

In spite of its non-official status, the large calorie is still widely used as a unit of food energy. The small calorie is also often used for measurements in chemistry, although the amounts involved are typically recorded in kilocalories.

Centimetre–gram–second system of units

The centimetre–gram–second system of units (abbreviated CGS or cgs) is a variant of the metric system based on the centimetre as the unit of length, the gram as the unit of mass, and the second as the unit of time. All CGS mechanical units are unambiguously derived from these three base units, but there are several different ways of extending the CGS system to cover electromagnetism.The CGS system has been largely supplanted by the MKS system based on the metre, kilogram, and second, which was in turn extended and replaced by the International System of Units (SI). In many fields of science and engineering, SI is the only system of units in use but there remain certain subfields where CGS is prevalent.

In measurements of purely mechanical systems (involving units of length, mass, force, energy, pressure, and so on), the differences between CGS and SI are straightforward and rather trivial; the unit-conversion factors are all powers of 10 as 100 cm = 1 m and 1000 g = 1 kg. For example, the CGS unit of force is the dyne which is defined as 1 g⋅cm/s2, so the SI unit of force, the newton (1 kg⋅m/s2), is equal to 100,000 dynes.

On the other hand, in measurements of electromagnetic phenomena (involving units of charge, electric and magnetic fields, voltage, and so on), converting between CGS and SI is more subtle. Formulas for physical laws of electromagnetism (such as Maxwell's equations) need to be adjusted depending on which system of units one uses. This is because there is no one-to-one correspondence between electromagnetic units in SI and those in CGS, as is the case for mechanical units. Furthermore, within CGS, there are several plausible choices of electromagnetic units, leading to different unit "sub-systems", including Gaussian units, "ESU", "EMU", and Lorentz–Heaviside units. Among these choices, Gaussian units are the most common today, and "CGS units" often used specifically refers to CGS-Gaussian units.

Coccus

A coccus (plural cocci) is any bacterium or archaeon that has a spherical, ovoid, or generally round shape. It is one of the three distinct bacterial shapes, the other two being bacillus (rod-shaped) and spiral-shaped cells.

Cocci is an English loanword of a modern or neo-Latin noun, which in turn stems from the Greek masculine noun cóccos (κόκκος) meaning "berry".

Food energy

Food energy is chemical energy that animals (including humans) derive from food through the process of cellular respiration. Cellular respiration may either involve the chemical reaction of food molecules with molecular oxygen (aerobic respiration) or the process of reorganizing the food molecules without additional oxygen (anaerobic respiration).

Gram-negative bacteria

Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the gram-staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall sandwiched between an inner cytoplasmic cell membrane and a bacterial outer membrane.

Gram-negative bacteria are found everywhere, in virtually all environments on Earth that support life. The gram-negative bacteria include the model organism Escherichia coli, as well as many pathogenic bacteria, such as Pseudomonas aeruginosa, Neisseria gonorrhoeae, Chlamydia trachomatis, and Yersinia pestis. They are an important medical challenge, as their outer membrane protects them from many antibiotics (including penicillin); detergents that would normally damage the peptidoglycans of the (inner) cell membrane; and lysozyme, an antimicrobial enzyme produced by animals that forms part of the innate immune system. Additionally, the outer leaflet of this membrane comprises a complex lipopolysaccharide (LPS) whose lipid A component can cause a toxic reaction when these bacteria are lysed by immune cells. This toxic reaction can include fever, an increased respiratory rate, and low blood pressure — a life-threatening condition known as septic shock.Several classes of antibiotics have been designed to target gram-negative bacteria, including aminopenicillins, ureidopenicillins, cephalosporins, beta-lactam-betalactamase combinations (e.g. pipercillin-tazobactam), Folate antagonists, quinolones, and carbapenems. Many of these antibiotics also cover gram positive organisms. The drugs that specifically target gram negative organisms include aminoglycosides, monobactams (aztreonam) and Ciprofloxacin.

Gram-positive bacteria

Gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their cell wall.

Gram-positive bacteria take up the crystal violet stain used in the test, and then appear to be purple-coloured when seen through a microscope. This is because the thick peptidoglycan layer in the bacterial cell wall retains the stain after it is washed away from the rest of the sample, in the decolorization stage of the test.

Gram-negative bacteria cannot retain the violet stain after the decolorization step; alcohol used in this stage degrades the outer membrane of gram-negative cells, making the cell wall more porous and incapable of retaining the crystal violet stain. Their peptidoglycan layer is much thinner and sandwiched between an inner cell membrane and a bacterial outer membrane, causing them to take up the counterstain (safranin or fuchsine) and appear red or pink.

Despite their thicker peptidoglycan layer, gram-positive bacteria are more receptive to certain cell wall targeting antibiotics than gram-negative bacteria, due to the absence of the outer membrane.

Gram panchayat

A gram panchayat (village council) is the only grassroots-level of panchayati raj formalised local self-governance system in India at the village or small-town level, and has a sarpanch as its elected head.The failed attempts to deal with local matters at the national level caused, in 1992, the reintroduction of panchayats for their previously used purpose as an organisation for local self-governance. There are about 250,000 gram panchayats in India, that are being gigabit-broadband enabled under the BharatNet and Digital India initiative.

Gram stain

Gram stain or Gram staining, also called Gram's method, is a method of staining used to distinguish and classify bacterial species into two large groups (gram-positive and gram-negative). The name comes from the Danish bacteriologist Hans Christian Gram, who developed the technique.

Gram staining differentiates bacteria by the chemical and physical properties of their cell walls by detecting peptidoglycan, which is present in the cell wall of Gram-positive bacteria. Gram-negative cells also contain peptidoglycan, but a very small layer of it that is dissolved when the alcohol is added. This is why the cell loses its initial color from the primary stain. Gram-positive bacteria retain the crystal violet dye, and thus are stained violet, while the Gram-negative bacteria do not; after washing, a counterstain is added (commonly safranin or fuchsine) that will stain these Gram-negative bacteria a pink color. Both Gram-positive bacteria and Gram-negative bacteria pick up the counterstain. The counterstain, however, is unseen on Gram-positive bacteria because of the darker crystal violet stain.

The Gram stain is almost always the first step in the preliminary identification of a bacterial organism. While Gram staining is a valuable diagnostic tool in both clinical and research settings, not all bacteria can be definitively classified by this technique. This gives rise to gram-variable and gram-indeterminate groups.

Kilogram-force

The kilogram-force (kgf or kgF), or kilopond (kp, from Latin pondus meaning weight), is a gravitational metric unit of force. It is equal to the magnitude of the force exerted on one kilogram of mass in a 9.80665 m/s2 gravitational field (standard gravity, a conventional value approximating the average magnitude of gravity on Earth). Therefore, one kilogram-force is by definition equal to 9.80665 N. Similarly, a gram-force is 9.80665 mN, and a milligram-force is 9.80665 μN. One kilogram-force is approximately 2.204622 pound-force.

Kilogram-force is a non-standard unit and is classified in SI Metric System as a unit that is unacceptable for use with SI.

Molar mass

In chemistry, the molar mass M is a physical property defined as the mass of a given substance (chemical element or chemical compound) divided by the amount of substance. The base SI unit for molar mass is kg/mol. However, for historical reasons, molar masses are almost always expressed in g/mol.

In simple terms, molar mass of a substance is the total weight of that substance (in either kilogram or gram) for one mole of that substance. That is, the weight of a substance for 6.02214076×10^23 molecules or atoms of that substance.

As an example, the molar mass of water: M(H2O) ≈ 18.015 g/mol.

Mole (unit)

The mole is the unit of measurement for amount of substance in the International System of Units (SI). Effective 20 May 2019, the mole is defined as the amount of a chemical substance that contains exactly 6.02214076×1023 (Avogadro's constant) constitutive particles, e.g., atoms, molecules, ions or electrons. This definition was adopted in November of 2018, revising its old definition based on the number of atoms in 12 grams of carbon-12 (12C) (the isotope of carbon with standard atomic weight 12 by definition). The mole is an SI base unit, with the unit symbol mol.

The mole is widely used in chemistry as a convenient way to express amounts of reactants and products of chemical reactions. For example, the chemical equation 2H2 + O2 → 2H2O can be interpreted to mean that 2 mol dihydrogen (H2) and 1 mol dioxygen (O2) react to form 2 mol water (H2O). The mole may also be used to represent the number of atoms, ions, or other entities in a given sample of a substance. The concentration of a solution is commonly expressed by its molarity, defined as the amount of dissolved substance per unit volume of solution, for which the unit typically used is moles per litre (mol/l).

The term gram-molecule was formerly used for essentially the same concept. The term gram-atom has been used for a related but distinct concept, namely a quantity of a substance that contains Avogadro's number of atoms, whether isolated or combined in molecules. Thus, for example, 1 mole of MgBr2 is 1 gram-molecule of MgBr2 but 3 gram-atoms of MgBr2.

Mung bean

The mung bean (Vigna radiata), alternatively known as the green gram, maash, or moong Sanskrit मुद्ग / mudga, is a plant species in the legume family. The mung bean is mainly cultivated in India, Pakistan, Bangladesh, Nepal, Sri Lanka, China, Taiwan, Korea, South Asia and Southeast Asia. It is used as an ingredient in both savory and sweet dishes.

Panchayati raj (India)

In India, the Panchayati Raj generally refers to the system of local self-government in India introduced by a constitutional amendment in 1992, although it is based upon the traditional panchayat system of South Asia. This Panchayati Raj system was formalized in 1992, following a study conducted by a number of Indian committees on various ways of implementing more decentralized administration. The modern Panchayati Raj and its Gram Panchayats are not to be confused with the extra-constitutional Khap Panchayats (or Caste Panchayats) found in northern India.In India, the Panchayati Raj now functions as a system of governance in which gram panchayats are the basic units of local administration. The system has three levels: Gram Panchayat (village level), Mandal Parishad or Block Samiti or Panchayat Samiti (block level), and Zila Parishad (district level). It was formalized in 1992 by the 73rd amendment to the Indian Constitution. Currently, the Panchayati Raj system exists in all states except Nagaland, Meghalaya, and Mizoram, and in all Union Territories except Delhi.The Panchayats receive funds from three sources:

Local body grants, as recommended by the Central Finance Commission

Funds for implementation of centrally sponsored schemes

Funds released by the state governments on the recommendations of the State Finance Commissions

Parallelogram

In Euclidean geometry, a parallelogram is a simple (non-self-intersecting) quadrilateral with two pairs of parallel sides. The opposite or facing sides of a parallelogram are of equal length and the opposite angles of a parallelogram are of equal measure. The congruence of opposite sides and opposite angles is a direct consequence of the Euclidean parallel postulate and neither condition can be proven without appealing to the Euclidean parallel postulate or one of its equivalent formulations.

By comparison, a quadrilateral with just one pair of parallel sides is a trapezoid in American English or a trapezium in British English.

The three-dimensional counterpart of a parallelogram is a parallelepiped.

The etymology (in Greek παραλληλ-όγραμμον, a shape "of parallel lines") reflects the definition.

Sarpanch

A sarpanch is an elected by the village-level constitutional body of local self-government called the panchayat (village government) in India (gram panchayat). The sarpanch, together with other elected panchas (members), constitute the gram panchayat. The sarpanch is the focal point of contact between government officers and the village community. Recently, there have been proposals to give sarpanches small judicial powers under Gram Panchayat. In some states of India such as Bihar, sarpanch has been empowered to look into various civil and criminal cases, and given judicial power to punish and impose fine on those violating rules.

Spore

In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, fungi and protozoa. Bacterial spores are not part of a sexual cycle but are resistant structures used for survival under unfavourable conditions. Myxozoan spores release amoebulae into their hosts for parasitic infection, but also reproduce within the hosts through the pairing of two nuclei within the plasmodium, which develops from the amoebula.Spores are usually haploid and unicellular and are produced by meiosis in the sporangium of a diploid sporophyte. Under favourable conditions the spore can develop into a new organism using mitotic division, producing a multicellular gametophyte, which eventually goes on to produce gametes. Two gametes fuse to form a zygote which develops into a new sporophyte. This cycle is known as alternation of generations.

The spores of seed plants, however, are produced internally and the megaspores, formed within the ovules and the microspores are involved in the formation of more complex structures that form the dispersal units, the seeds and pollen grains.

Torque

Torque, moment, or moment of force is the rotational equivalent of linear force. The concept originated with the studies of Archimedes on the usage of levers. Just as a linear force is a push or a pull, a torque can be thought of as a twist to an object. The symbol for torque is typically , the lowercase Greek letter tau. When being referred to as moment of force, it is commonly denoted by M.

In three dimensions, the torque is a pseudovector; for point particles, it is given by the cross product of the position vector (distance vector) and the force vector. The magnitude of torque of a rigid body depends on three quantities: the force applied, the lever arm vector connecting the origin to the point of force application, and the angle between the force and lever arm vectors. In symbols:

where

is the torque vector and is the magnitude of the torque,
r is the position vector (a vector from the origin of the coordinate system defined to the point where the force is applied)
F is the force vector,
× denotes the cross product, which is defined as magnitudes of the respective vectors times .
is the angle between the force vector and the lever arm vector.

The SI unit for torque is N⋅m. For more on the units of torque, see Units.

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