A machine is a mechanical structure that uses power to apply forces and control movement to perform an intended action. Machines can be driven by animals and people, by natural forces such as wind and water, by chemical, thermal, or electrical power, include a system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement, they can include computers and sensors that monitor performance and plan movement called mechanical systems. Renaissance natural philosophers identified six simple machines which were the elementary devices that put a load into motion, calculated the ratio of output force to input force, known today as mechanical advantage. Modern machines are complex systems that consist of structural elements and control components and include interfaces for convenient use. Examples include a wide range of vehicles, such as automobiles and airplanes, appliances in the home and office, including computers, building air handling and water handling systems, as well as farm machinery, machine tools and factory automation systems and robots.
The English word machine comes through Middle French from Latin machina, which in turn derives from the Greek. The word mechanical comes from the same Greek roots. A wider meaning of "fabric, structure" is found in classical Latin, but not in Greek usage; this meaning is found in late medieval French, is adopted from the French into English in the mid-16th century. In the 17th century, the word could mean a scheme or plot, a meaning now expressed by the derived machination; the modern meaning develops out of specialized application of the term to stage engines used in theater and to military siege engines, both in the late 16th and early 17th centuries. The OED traces the formal, modern meaning to John Harris' Lexicon Technicum, which has: Machine, or Engine, in Mechanicks, is whatsoever hath Force sufficient either to raise or stop the Motion of a Body... Simple Machines are reckoned to be Six in Number, viz. the Ballance, Pulley, Wheel and Screw... Compound Machines, or Engines, are innumerable.
The word engine used as a synonym both by Harris and in language derives from Latin ingenium "ingenuity, an invention". The hand axe, made by chipping flint to form a wedge, in the hands of a human transforms force and movement of the tool into a transverse splitting forces and movement of the workpiece; the idea of a simple machine originated with the Greek philosopher Archimedes around the 3rd century BC, who studied the Archimedean simple machines: lever and screw. Archimedes discovered the principle of mechanical advantage in the lever. Greek philosophers defined the classic five simple machines and were able to calculate their mechanical advantage. Heron of Alexandria in his work Mechanics lists five mechanisms that can "set a load in motion". However, the Greeks' understanding was limited to statics and did not include dynamics or the concept of work. During the Renaissance the dynamics of the Mechanical Powers, as the simple machines were called, began to be studied from the standpoint of how much useful work they could perform, leading to the new concept of mechanical work.
In 1586 Flemish engineer Simon Stevin derived the mechanical advantage of the inclined plane, it was included with the other simple machines. The complete dynamic theory of simple machines was worked out by Italian scientist Galileo Galilei in 1600 in Le Meccaniche, he was the first to understand that simple machines do not create energy, they transform it. The classic rules of sliding friction in machines were discovered by Leonardo da Vinci, but remained unpublished in his notebooks, they were rediscovered by Guillaume Amontons and were further developed by Charles-Augustin de Coulomb. James Watt patented his parallel motion linkage in 1782, which made the double acting steam engine practical; the Boulton and Watt steam engine and designs powered steam locomotives, steam ships, factories. The Industrial Revolution was a period from 1750 to 1850 where changes in agriculture, mining and technology had a profound effect on the social and cultural conditions of the times, it began in the United Kingdom subsequently spread throughout Western Europe, North America and the rest of the world.
Starting in the part of the 18th century, there began a transition in parts of Great Britain's manual labour and draft-animal-based economy towards machine-based manufacturing. It started with the mechanisation of the textile industries, the development of iron-making techniques and the increased use of refined coal; the idea that a machine can be decomposed into simple movable elements led Archimedes to define the lever and screw as simple machines. By the time of the Renaissance this list increased to include the wheel and axle and inclined plane; the modern approach to characterizing machines focusses on the components that allow movement, known as joints. Wedge: Perhaps the first example of a device designed to manage power is the hand axe called biface and Olorgesailie. A hand axe is made by chipping stone flint, to form a bifacial edge, or wedge. A wedge is a simple machine that transforms lateral force and movement o
In computer science and operations research, a genetic algorithm is a metaheuristic inspired by the process of natural selection that belongs to the larger class of evolutionary algorithms. Genetic algorithms are used to generate high-quality solutions to optimization and search problems by relying on bio-inspired operators such as mutation and selection. John Holland introduced genetic algorithms in 1960 based on the concept of Darwin’s theory of evolution. In a genetic algorithm, a population of candidate solutions to an optimization problem is evolved toward better solutions; each candidate solution has a set of properties which can be altered. The evolution starts from a population of randomly generated individuals, is an iterative process, with the population in each iteration called a generation. In each generation, the fitness of every individual in the population is evaluated; the more fit individuals are stochastically selected from the current population, each individual's genome is modified to form a new generation.
The new generation of candidate solutions is used in the next iteration of the algorithm. The algorithm terminates when either a maximum number of generations has been produced, or a satisfactory fitness level has been reached for the population. A typical genetic algorithm requires: a genetic representation of the solution domain, a fitness function to evaluate the solution domain. A standard representation of each candidate solution is as an array of bits. Arrays of other types and structures can be used in the same way; the main property that makes these genetic representations convenient is that their parts are aligned due to their fixed size, which facilitates simple crossover operations. Variable length representations may be used, but crossover implementation is more complex in this case. Tree-like representations are explored in genetic programming and graph-form representations are explored in evolutionary programming. Once the genetic representation and the fitness function are defined, a GA proceeds to initialize a population of solutions and to improve it through repetitive application of the mutation, crossover and selection operators.
The population size depends on the nature of the problem, but contains several hundreds or thousands of possible solutions. The initial population is generated randomly, allowing the entire range of possible solutions; the solutions may be "seeded" in areas where optimal solutions are to be found. During each successive generation, a portion of the existing population is selected to breed a new generation. Individual solutions are selected through a fitness-based process, where fitter solutions are more to be selected. Certain selection methods rate the fitness of each solution and preferentially select the best solutions. Other methods rate only a random sample of the population, as the former process may be time-consuming; the fitness function is defined over the genetic representation and measures the quality of the represented solution. The fitness function is always problem dependent. For instance, in the knapsack problem one wants to maximize the total value of objects that can be put in a knapsack of some fixed capacity.
A representation of a solution might be an array of bits, where each bit represents a different object, the value of the bit represents whether or not the object is in the knapsack. Not every such representation is valid, as the size of objects may exceed the capacity of the knapsack; the fitness of the solution is the sum of values of all objects in the knapsack if the representation is valid, or 0 otherwise. In some problems, it is hard or impossible to define the fitness expression; the next step is to generate a second generation population of solutions from those selected through a combination of genetic operators: crossover, mutation. For each new solution to be produced, a pair of "parent" solutions is selected for breeding from the pool selected previously. By producing a "child" solution using the above methods of crossover and mutation, a new solution is created which shares many of the characteristics of its "parents". New parents are selected for each new child, the process continues until a new population of solutions of appropriate size is generated.
Although reproduction methods that are based on the use of two parents are more "biology inspired", some research suggests that more than two "parents" generate higher quality chromosomes. These processes result in the next generation population of chromosomes, different from the initial generation; the average fitness will have increased by this procedure for the population, since only the best organisms from the first generation are selected for breeding, along with a small proportion of less fit solutions. These less fit solutions ensure genetic diversity within the genetic po
Economic production quantity
The economic production quantity model determines the quantity a company or retailer should order to minimize the total inventory costs by balancing the inventory holding cost and average fixed ordering cost. The EPQ model was developed by E. W. Taft in 1918; this method is an extension of the economic order quantity model. The difference between these two methods is that the EPQ model assumes the company will produce its own quantity or the parts are going to be shipped to the company while they are being produced, therefore the orders are available or received in an incremental manner while the products are being produced. While the EOQ model assumes the order quantity arrives complete and after ordering, meaning that the parts are produced by another company and are ready to be shipped when the order is placed. In some literature, "economic manufacturing quantity" model is used for "economic production quantity" model. Similar to the EOQ model, EPQ is a single product lot scheduling method.
A multiproduct extension to these models is called product cycling problem. EPQ only applies where the demand for a product is constant over the year and that each new order is delivered/produced incrementally when the inventory reaches zero. There is a fixed cost regardless of the number of units ordered. There is a holding or storage cost for each unit held in storage. We want to determine the optimal number of units of the product to order so that we minimize the total cost associated with the purchase and storage of the product The required parameters to the solution are the total demand for the year, the purchase cost for each item, the fixed cost to place the order and the storage cost for each item per year. Note that the number of times an order is placed will affect the total cost, this number can be determined from the other parameters Demand for items from inventory is continuous and at a constant rate Production runs to replenish inventory are made at regular intervals During a production run, the production of items is continuous and at a constant rate Production set-up/ordering cost is fixed The lead time is fixed The purchase price of the item is constant, i.e. no discount is available The replenishment is made incrementally K = ordering/setup cost per production run D = yearly demand rate h = yearly holding cost per product T = cycle length P = yearly production rate x = D P Q = order quantity Holding Cost per Year = Q 2 h Where Q 2 is the average inventory level, h is the average holding cost.
Therefore, multiplying these two results in the holding cost per year. Ordering Cost per Year = D Q K Where D Q are the orders placed in a year, multiplied by K results in the ordering cost per year. We can notice from the equations above that the total ordering cost decreases as the production quantity increases. Inversely, the total holding cost increases. Therefore, in order to get the optimal production quantity we need to set holding cost per year equal to ordering cost per year and solve for quantity, the EPQ formula mentioned below. Ordering this quantity will result in the lowest total inventory cost per year. Average holding cost per unit time: 1 2 h D t Average ordering and holding cost as a function of time: x = 1 2 h D t + K t Infinite fill rate for the part being produced: Economic order quantity Demand is random: classical Newsvendor model Demand varies over time: Dynamic lot size model Several products produced on the same machine: Economic lot scheduling problem Reorder point Taft, E. W.
"The most economical production lot." Iron Age 101.18: 1410-1412. Gallego, G. "IEOR4000: Production Management", Columbia. Stevenson, W. J. "Operations Management" PowerPoint slide 19, The McGraw-Hill Companies. Kroeger, D. R. "Determining Economic Production in a Continuous Process" IIE Process Industries Webinar, IIE. Cárdenas-Barrón, L. E. "The Economic Production Quantity derived Algebraically" International Journal of Production Economics, Volume 77, Issue 1. Blumenfeld, D. "Inventory" Operations Research Calculations Handbook, Florida Harris, F. W. "How Many Parts To Make At Once" Factory, The Magazine of Management, 10, 135-136, 152
A bottling company is a commercial enterprise whose output is the bottling of beverages for distribution. Many bottling companies are franchisees of corporations such as Coca-Cola and PepsiCo who distribute the beverage in a specific geographic region; some bottling companies may bottle other local beverages such as regional beers or wines. A bottler is a company which fills up cans and bottles with the drink; the bottler distributes the final product to the wholesale sellers in a geographic area. Large companies like The Coca-Cola Company sell their product to bottlers like the Coca-Cola Bottling Co. Consolidated, who bottle and distribute it. List of bottling companies Bottling line Companies portal "American Bottler". Volume 42. American Bottler. February 1921. Retrieved September 27, 2012
Apple juice is a fruit juice made by the maceration and pressing of an apple. The resulting expelled juice may be further treated by enzymatic and centrifugal clarification to remove the starch and pectin, which holds fine particulate in suspension, pasteurized for packaging in glass, metal or aseptic processing system containers, or further treated by dehydration processes to a concentrate. Due to the complex and costly equipment required to extract and clarify juice from apples in large volume, apple juice is produced commercially. In the United States, unfiltered fresh apple juice is made by smaller operations in areas of high apple production, in the form of unclarified apple cider. Apple juice is one of the most common fruit juices in the world, with world production led by China, the United States, Germany. Apples used for apple juice are harvested between September and mid-November in the Northern Hemisphere and between February to mid April in the Southern Hemisphere. A common cultivar used for apple juice is the McIntosh.
Two medium McIntosh apples produce around 200 millilitres of juice. After the apples are picked, they are transported to the processing facility; the apples are pressed and juiced right away to avoid spoilage. Depending on the company and end-product, the apples can be processed in different ways before pressing. Apple juice is filtered, with the quantity of solid particles remaining defining the difference between apple juice and apple cider. In cases where the apple juice is treated enzymatically, the typical class of enzymes used are pectinases. Vitamin C is sometimes added by fortification, because content is variable, much of, lost in processing. Vitamin C helps to prevent oxidation of the product. Other vitamin concentrations are low, but apple juice does contain various mineral nutrients, including boron, which may promote healthy bones. Apple juice has a significant concentration of natural phenols of low molecular weight and procyanidins. Apple juice has been shown to reduce oxidative stress on the brains of aging lab mice.
Research suggests that apple juice increases acetylcholine in the brain resulting in improved memory. Despite having some health benefits, apple juice is high in sugar, it has 28 grams of carbohydrates. This results in 130 calories per 230 g – protein and fat are not significant. Like most fruit juice, apple juice contains a similar amount of sugar as the raw fruit, but lacks the fiber content. While apple juice refers to the filtered, pasteurised product of apple pressing, an unfiltered and sometimes unpasteurised version of the juice is known as "apple cider" in the United States and parts of Canada. Seeking to capitalize on this, some makers of filtered and clarified juice label and sell their product as "apple cider". Legal distinctions are not universal, elusive to apply. Elsewhere in the world in New Zealand and the United Kingdom, the simple term cider refers to fermented fruit juice made from apples but from pears; because apple juice is acidic with a pH of 3.4, it can be pasteurized for less time or at lower temperatures than many other juices.
For this purpose, the U. S. Food and Drug Administration recommends the following thermal processing times and temperatures in order to achieve a 5-log reduction of Cryptosporidium parvum as this parasite is more heat resistant than E.coli 0157: 160 °F for at least 6 seconds, 165 °F for at least 2.8 seconds, 170 °F for at least 1.3 seconds, 175 °F for at least 0.6 seconds, 180 °F for at least 0.3 seconds, From 2000 to 2010 there were over 1700 cases in North America of illnesses related to drinking unpasteurized juice and ciders. The pathogens related to these food-borne illnesses included parasites and viruses; the most common pathogens were E.coli 0157 and 0111, Cryptosporidium, Clostridium botulinum, Hepatitis A. Pathogens can be spread in a number of ways, such as contamination where the fruit is grown, being carried in contaminated containers, or due to poor handling and washing. Fresh apple juice requires refrigeration. Sealed bottles of canned apple juice can be stored in a dark, cool place, such as a pantry or cupboard, to delay the degradation of the product.
The appearance, texture, or taste of the juice might change over time. Once the juice package is opened, or if it was not sealed and shipped without needing refrigeration by the manufacturer, it must be resealed and refrigerated to avoid contamination from microorganisms such as bacteria; the ideal storage temperature for apple juice is between 0 °C and 4 °C. List of juices Malic acid
Orange juice is a liquid extract of the orange tree fruit, produced by squeezing oranges. It comes in several different varieties, including blood orange, navel oranges, valencia orange and tangerine; as well as variations in oranges used, some varieties include differing amounts of juice vesicles, known as "pulp" in American English, " bits" in British English. These vesicles contain the juice of the orange and can be left in or removed during the manufacturing process. How juicy these vesicles are depend upon many factors, such as species and season. In American English, the beverage name is abbreviated as "OJ". Commercial orange juice with a long shelf life is made by pasteurizing the juice and removing the oxygen from it; this removes much of the taste, necessitating the addition of a flavor pack made from orange products. Additionally, some juice is further processed by drying and rehydrating the juice, or by concentrating the juice and adding water to the concentrate; the health value of orange juice is debatable: it has a high concentration of vitamin C, but a high concentration of simple sugars, comparable to soft drinks.
As a result, some government nutritional advice has been adjusted to encourage substitution of orange juice with raw fruit, digested more and limit daily consumption. During World War II, American soldiers rejected vitamin C-packed lemon crystals because of their unappetizing taste, thus the government searched for a food that would fulfill the nutritional needs of the soldiers, have a desirable taste, prevent diseases such as scurvy in a transportable vitamin C product. The federal government, the Florida department of Citrus, along with a group of scientists desired to develop a superior product to canned orange juice and developed frozen concentrated orange juice. Frozen concentrated orange juice was developed three years after the war had ended. By 1949, orange juice processing plants in Florida were producing over 10 million gallons of concentrated orange juice. Consumers were captivated with the idea of concentrated canned orange juice as it was affordable, convenient, a vitamin-C packed product.
The preparation was simple, thaw the juice, add water, stir. However, by the 1980s, food scientists developed a more fresh-tasting juice known as reconstituted ready to serve juice. In the 1990s, "not from concentrate" orange juice was developed and gave consumers an new perspective of orange juice transforming the product from can to freshness in a carton. Orange juice is a common breakfast beverage in the United States. Due to the importance of oranges to the economy of Florida, "the juice obtained from mature oranges of the species Citrus sinensis and hybrids thereof" was adopted as the official beverage of Florida in 1967. A cup serving of raw, fresh orange juice, amounting to 248 grams or 8 ounces, has 124 mg of vitamin C, it has 20.8 g of sugars, 112 Calories and 26 grams of carbohydrates. It supplies potassium and folate. Citrus juices contain flavonoids. Orange juice is a source of the antioxidant hesperidin; because of its citric acid content, orange juice is acidic, with a typical pH of around 3.5.
Commercial squeezed orange juice is pasteurized and filtered before being evaporated under vacuum and heat. After removal of most of the water, this concentrate, about 65% sugar by weight, is stored at about 10 °F. Essences, Vitamin C, oils extracted during the vacuum concentration process may be added back to restore flavor and nutrition; when water is added to freshly thawed concentrated orange juice, it is said to be reconstituted. The product was developed in 1948 at the University of Florida's Citrus Research and Education Center. Since, it has emerged as a soft commodity, futures contracts have traded in New York since 1966. Options on FCOJ were introduced in 1985. From the late 1950s to the mid-1980s, the product had the greatest orange juice market share, but not-from-concentrate juices surpassed FCOJ in the 1980s. Orange juice, pasteurized and sold to consumers without having been concentrated is labeled as "not from concentrate". Just as "from concentrate" processing, most "not from concentrate" processing reduces the natural flavor from the juice.
The largest producers of "not from concentrate" use a production process where the juice is placed in aseptic storage, with the oxygen stripped from it, for up to a year. Removing the oxygen strips out flavor-providing compounds, so manufacturers add a flavor pack in the final step, which Cooks Illustrated magazine describes as containing "highly engineered additives." Flavor pack formulas vary by region, because consumers in different parts of the world have different preferences related to sweetness and acidity. According to the citrus industry, the Food and Drug Administration does not require the contents of flavor packs to be detailed on a product's packaging. One common component of flavor packs is ethyl butyrate, a natural aroma that people associate with freshness, and, removed from juice during pasteurization and storage. Cooks Illustrated sent juice samples to independent laboratories, found that while fresh-squeezed juice contained about 1.19 milligrams of ethyl butyrate per liter, juice, commercially processed had levels as high as 8.53 milligrams per liter.
A small fraction of fresh orange juice is canned. Canned orange juice retains vitamin C much better than bottled juice; the canned product loses flavor, when stored at room temperature for more than 12 weeks. In the early years
Milk is a nutrient-rich, white liquid food produced by the mammary glands of mammals. It is the primary source of nutrition for infant mammals before they are able to digest other types of food. Early-lactation milk contains colostrum, which carries the mother's antibodies to its young and can reduce the risk of many diseases, it contains many other nutrients including lactose. Interspecies consumption of milk is not uncommon among humans, many of whom consume the milk of other mammals; as an agricultural product, milk called dairy milk, is extracted from farm animals during or soon after pregnancy. Dairy farms produced about 730 million tonnes of milk from 260 million dairy cows. India is the world's largest producer of milk, is the leading exporter of skimmed milk powder, yet it exports few other milk products; the increasing rise in domestic demand for dairy products and a large demand-supply gap could lead to India being a net importer of dairy products in the future. The United States, India and Brazil are the world's largest exporters of milk and milk products.
China and Russia were the world's largest importers of milk and milk products until 2016 when both countries became self-sufficient, contributing to a worldwide glut of milk. Throughout the world, more than six billion people consume milk products. Over 750 million people live in dairy farming households; the term "milk" comes from "Old English meoluc, from Proto-Germanic *meluks "milk"". Milk consumption occurs in two distinct overall types: a natural source of nutrition for all infant mammals and a food product obtained from other mammals for consumption by humans of all ages. In all mammals, milk is fed to infants through breastfeeding, either directly or by expressing the milk to be stored and consumed later; the early milk from mammals is called colostrum. Colostrum contains antibodies that provide protection to the newborn baby as well as nutrients and growth factors; the makeup of the colostrum and the period of secretion varies from species to species. For humans, the World Health Organization recommends exclusive breastfeeding for six months and breastfeeding in addition to other food for up to two years of age or more.
In some cultures it is common to breastfeed children for three to five years, the period may be longer. Fresh goats' milk is sometimes substituted for breast milk, which introduces the risk of the child developing electrolyte imbalances, metabolic acidosis, megaloblastic anemia, a host of allergic reactions. In many cultures in the West, humans continue to consume milk beyond infancy, using the milk of other mammals as a food product; the ability to digest milk was limited to children as adults did not produce lactase, an enzyme necessary for digesting the lactose in milk. People therefore converted milk to curd and other products to reduce the levels of lactose. Thousands of years ago, a chance mutation spread in human populations in Europe that enabled the production of lactase in adulthood; this mutation allowed milk to be used as a new source of nutrition which could sustain populations when other food sources failed. Milk is processed into a variety of products such as cream, yogurt, ice cream, cheese.
Modern industrial processes use milk to produce casein, whey protein, condensed milk, powdered milk, many other food-additives and industrial products. Whole milk and cream have high levels of saturated fat; the sugar lactose is found only in milk, forsythia flowers, a few tropical shrubs. The enzyme needed to digest lactose, reaches its highest levels in the human small intestine after birth and begins a slow decline unless milk is consumed regularly; those groups who do continue to tolerate milk, however have exercised great creativity in using the milk of domesticated ungulates, not only of cattle, but sheep, yaks, water buffalo, horses and camels. India is buffalo milk in the world. In food use, from 1961, the term milk has been defined under Codex Alimentarius standards as: "the normal mammary secretion of milking animals obtained from one or more milkings without either addition to it or extraction from it, intended for consumption as liquid milk or for further processing." The term dairy relates to animal milk production.
A substance secreted by pigeons to feed their young is called "crop milk" and bears some resemblance to mammalian milk, although it is not consumed as a milk substitute. The definition above precludes non-animal products which resemble dairy milk in color and texture, such as almond milk, coconut milk, rice milk, soy milk. In English, the word "milk" has been used to refer to "milk-like plant juices" since 1200 AD. In the USA, milk alternatives now command 13% of the "milk" market, leading the US dairy industry to attempt, multiple times, to sue producers of dairy milk alternatives, to have the name "milk" limited to animal milk, so far without success; the mammary gland is thought to have derived from apocrine skin glands. It has been suggested. Much of the argument is based on monotremes; the original adaptive significance of milk secretions may have been nutrition or immunological protection. This secretion became more copious and accrued nutritional complexity over evolutionary time. Tritylodontid cynodonts seem to have displayed lactation, based on