Role in "The Simpsons".

Nelson is a 12-year-old student and bully at Springfield Elementary School. He is known to have terrorized virtually every kid in Springfield at one point or another. Most often, however, it is the school nerds and less popular students, such as Milhouse and Martin, who are the subject of his cruelty. Nelson shows the occasional glimpse of humanity, though, and other characters have occasionally warmed to him; Lisa dates him briefly in "Lisa's Date with Density", Marge informally adopts him in "Sleeping with the Enemy", and Bart is shown as a friend to him several times, such as in "The Haw-Hawed Couple".  His family life is dysfunctional. While some early episodes offer inconsistent histories (such as Nelson's dad going insane and abandoning him, Nelson's parents divorcing because of his mom's cough drop addiction, or Nelson's dad in prison while his mom "has bigger problems"), the canon story that has evolved is that he lives in a dilapidated house with his mother, who works on the fringes of the sex industry, either as a waitress at Hooters or in a topless bar. The character design and voice portrayal of both parents has varied throughout the course of the series.  It is shown in many episodes that Nelson's father abandoned him and his mother at an early age when he "went to pick up some Pop-Tarts" although, later on in the series, he was said to have gone to pick up a pack of cigarettes. In the fourth-season episode "Brother from the Same Planet", Nelson's father is the children's soccer coach who awards Nelson with a free trip to Pele's Soccer and Acting Camp. Nelson's father also appears briefly in the sixth-season episode "Bart's Girlfriend", depicted capturing Nelson with a leash as the children run through the cornfields in an attempt to avoid attending church. He also appears in the ninth-season episode "Bart Star" to congratulate Nelson after a football game victory and take him to Hooters (with Nelson turning down the invitation because he "doesn't want to bother [his] Mom at work"). Nelson's father returns in the sixteenth-season episode "Sleeping with the Enemy". It turns out that he did not leave Nelson deliberately; he bit into a chocolate bar, not knowing it had peanuts and had an allergic reaction, covering 90% of his body with large tumors. Looking like Joseph Merrick, he ran out of the store and encountered a circus that made him a part of its freak show. At performances, circus attendees threw peanuts at him, which perpetuated his reaction, preventing him from returning to normal. When the circus came through Springfield, Bart recognized him and brought him home to rid himself of Nelson (who had been taken into the Simpson home by Marge).  Nelson is also a natural athlete. In the episode "Bart Star", Nelson almost singlehandedly carries the entire Springfield Pee-Wee football team. As the team quarterback, he also on one occasion catches his own pass and plows through the opposing team with extreme ease. In various episodes, he gives out the impression that he is a lot smarter than he may first appear. Nelson often points out painfully obvious things to adults and kids alike that take them longer to grasp. Another example is a running joke where Nelson does a class assignment that is implied to be of high quality. However, he is always brushed off by the teachers before he gets to show them his work. Another running joke, though, is Nelson presenting ridiculously simple assignments, such as repeatedly showing a can of tomato paste in Show and Tell, and a presentation on "The Grapes of Wrath", consisting of himself crushing a bunch of grapes with a hammer, stating "Here's the grapes, and here's the wrath!" In later episodes, Nelson shows signs of being a tormented artist type, even submitting a film to the Sundance Film Festival about his life as a child living in poverty with a single, unfit mother and no strong father figure. He memorably says in the documentary, "I like to cry at the ocean, because only there do my tears seem small."  In the episode "Little Big Girl", it is revealed that Nelson is German-American. Ironically, in "Much Apu About Nothing", Nelson picks on foreign exchange student Üter for being German during Springfield's anti-immigration mania. He is shown to be a big fan of Andy Williams as he, Bart, Milhouse and Martin went to a concert performed by him in "Bart on the Road".

Relationships with other characters.

Even though in the first season (and for many seasons afterwards) Nelson seemed to be Bart's antagonist, he eventually becomes what can be considered as Bart's second closest friend after Milhouse.  In his debut episode, Lisa was the initial target of Nelson's bullying, which prompted Bart to defend her. Bart's actions resulted in frequent beatings by Nelson and his gang, but finally ended when Bart received help from Herman, who came up with the idea of standing up to Nelson and his gang by pelting them with water balloons. From that point on, Nelson shows a grudging respect for Bart, though he occasionally reverts to his past behavior towards him.  Although still prone to violence, Nelson hangs out with Bart and his less popular friends, such as Milhouse Van Houten and occasionally even common bullying target Martin Prince. In "The Debarted", it is shown that Nelson has become Bart's "other best friend", along with Milhouse.  Nelson has many other moments where he displays his hidden good nature, such as his brief amorous relationship with Lisa. Although he cannot control his delinquent tendencies, he treats her with respect and even tries to change for her, although both of them realize that he is not being true to himself by doing so. In "Lisa's Date with Density", Nelson kisses Lisa, only to be berated by Jimbo, Kearney, and Dolph, who believe that kissing girls is "gay" (despite the events that occurred revolving around Jimbo in "New Kid On The Block").  He also punishes Sherri and Terri for tormenting Lisa. Another curious example of his "good side" is with Martin, a boy whom Nelson picks on perhaps more so than any other kid in town. Despite the utter cruelty, there are occasional hints that Nelson does not harbor any real hatred towards Martin and only does so to maintain his 'tough guy' reputation. In "Dial 'N' for Nerder", when it is believed that Martin has died, Nelson endeavours to learn the truth and find Martin's killers. When it is revealed that Martin is alive, Nelson mocks and punches him, but also states that he is glad Martin is not dead. In this same episode, however, when Lisa tries to bribe him to not rat her out by offering to get back together with him, he rejects it. In another episode, it is revealed that both Martin and Nelson went to space camp, and that Nelson was a loyal officer to Martin. (See "I'm Spelling as Fast as I Can")  In "Loan-a Lisa", Lisa uses $50 to help Nelson fund his bicycle company, which becomes a success. When Nelson almost drops out of school to spend more time on the company, Lisa is saddened and attempts to stop him from doing so, but eventually respects his decision after realising he won't change despite the money used to fund it. Nelson eventually decides not to drop out after all and takes Lisa skating to make it up to her.  Though Nelson is often said to not really have friends aside from his on-and-off relationship with Bart and the others, Nelson sometimes hangs out with his fellow school bullies Jimbo, Dolph, Kearney, and (to a lesser extent) two smaller and younger fraternal twin minions known as the Weasels. Though only seen with them occasionally, Nelson is also ironically the leader of the school bullies (possibly by virtue of being the most often seen and most recognizable of the gang).  In "Sleeping with the Enemy", Moe Szyslak appears briefly during a Muntz family reunion. The facial similarities between Moe and the Muntz are surprisingly quite apparent and Moe's childhood experiences and behaviors are somewhat relatable with Nelson's. Moe briefly appears and claims that he is part of the family and is then shunned off screen by the Muntz' confused looks.

Character.

"The Simpsons" creator Matt Groening named Nelson after the wrestling hold of the same name. Cast member Nancy Cartwright voices the character, which first appeared in the fifth episode of the first season, "Bart the General" (1990). American voice actress Dana Hill was first supposed to provide Nelson's voice, and attended the read-through of the episode. However, as Cartwright wrote in her autobiography "My Life as a 10-Year-Old Boy", "the producers were still putting together this ensemble of [actors] and, come Monday, at the recording, she was nowhere to be found and the part was assigned to me. I didn't have time to ask why and I still don't have a clue." Cartwright also commented that when she first found out she would be voicing Nelson, "I asked myself, 'What does a bully sound like?' Well... what you hear is what you get. When I first uttered, 'I'll get you after school, man!' I let out a sigh of relief when I got through the line and a double-sigh when it got a laugh."  By the eighth season of "The Simpsons", the writers had begun to explore the secondary characters of the show. "Lisa's Date with Density" (season eight, 1996) was the first episode to center around Nelson and was used to explain why he acts the way he does. The idea of Nelson dating Lisa Simpson had already been around for a while, but this was the first time that the staff worked it into the show. Cartwright said in 2012 that she thinks Nelson "has evolved the most out of all the characters I do. There's a soft spot in him that the writers have found. He's got this special attraction to Marge, and he sings these songs, and he's got a crush on Lisa. There's something about this poor kid – his mother works at Hooters, his dad went out to buy milk and never came back. I wouldn't want him to come over for dinner, but I really love doing his voice."

Reception.

The episode "The Haw-Hawed Couple" in 2007 was nominated for the Emmy Award for Outstanding Animated Program. The writer of the episode Matt Selman was nominated for a Writers Guild of America Award.  In his review of the season 22 episode "Loan-a Lisa", Rowan Kaiser of "The A.V. Club" commented that Nelson's character has undergone a "Spikeification", in reference to the bully's near-exclusive portrayal as being likable and vulnerable in later seasons of the program.

Nelson Mandela Muntz is a fictional character and the lead school bully from the animated television series "The Simpsons", best known for his signature mocking laugh "Ha-ha!". He is voiced by Nancy Cartwright and was introduced in Season 1's "Bart the General" as an antagonist but later became a close friend of Bart Simpson.

Nelson Mandela Muntz est un personnage de la série télévisée "Les Simpson". C'est une brute qui passe son temps à errer dans les rues en quête d'un mauvais coup à faire... Il ne manque pas une occasion de se moquer de quelqu'un grâce à son rire célèbre et méprisant « Ha! Ha! ». Il est un des antagonistes de la série, un ennemi de Bart.


Content.

This 50-second silent film shows the entry of a train pulled by a steam locomotive into the gare de La Ciotat, the train station of the French coastal town of La Ciotat. Like most of the early Lumière films, "L'arrivée d'un train en gare de La Ciotat" consists of a single, unedited view illustrating an aspect of everyday life. There is no apparent intentional camera movement, and the film consists of one continuous real-time shot.

Production.

This 50-second movie was filmed in La Ciotat, Bouches-du-Rhône, France. It was filmed by means of the Cinématographe, an all-in-one camera, which also serves as a printer and film projector. As with all early Lumière movies, this film was made in a 35 mm format with an aspect ratio of 1.33:1.

Contemporary reaction.

The film is associated with an urban legend well known in the world of cinema. The story goes that when the film was first shown, the audience was so overwhelmed by the moving image of a life-sized train coming directly at them that people screamed and ran to the back of the room. Hellmuth Karasek in the German magazine "Der Spiegel" wrote that the film "had a particularly lasting impact; yes, it caused fear, terror, even panic." However, some have doubted the veracity of this incident such as film scholar and historian in his essay, "Lumiere's Arrival of the Train: Cinema's Founding Myth". Others such as theorist Benjamin H. Bratton have speculated that the alleged reaction may have been caused by the projection being mistaken for a camera obscura by the audience which at the time would have been the only other technique to produce a naturalistic moving image. Whether or not it actually happened, the film undoubtedly astonished people unaccustomed to the illusion created by moving images.

Cinematic techniques.

This film is interesting because it contains the first example of several common cinematic techniques: camera angle, long shot, medium shot, close-up, and forced perspective.  It is evident from their films, taken as a whole, that the Lumière brothers knew what the effect of their choice of camera placement would be. They placed the camera on the platform to produce a dramatic increase in the size of the arriving train. The train arrives from a distant point and bears down on the viewer, finally crossing the lower edge of the screen.  A significant aspect of the film is that it illustrates the use of the long shot to establish the setting of the film, followed by a medium shot, and then a close-up. As the camera is static for the entire film, the effect of these various "shots" is achieved by the movement of the subject alone. Nonetheless, these different types of shots are clearly illustrated here. Later filmmakers moved their cameras to achieve these shots.

3D version.

What most film histories leave out is that the Lumière Brothers were trying to achieve a 3D image even prior to this first-ever public exhibition of motion pictures. Louis Lumière eventually re-shot "L'Arrivée d’un Train" with a stereoscopic film camera and exhibited it (along with a series of other 3D shorts) at a 1934 meeting of the French Academy of Science. Given the contradictory accounts that plague early cinema and pre-cinema accounts, it is plausible that early cinema historians conflated the audience reactions at these separate screenings of "L'Arrivée d’un Train". The intense audience reaction fits better with the latter exhibition, when the train apparently "was" actually coming out of the screen at the audience. But due to the fact that the 3D film never took off commercially as the conventional 2D version did, including such details would not make for a compelling myth.

Current status.

The short has been featured in a number of film collections including "Landmarks of Early Film volume 1". A screening of the film was depicted in the 2011 film "Hugo", and in the intro sequence for the 2013 video game "". The scene of the train pulling in was placed at #100 on Channel 4's two-part documentary "The 100 Greatest Scary Moments".  In March 2017, the film was encoded into DNA by Yaniv Erlich and Dina Zielinski.  In 2020 was created upscaled and resounded version of a classic B&W movie: Arrival of a Train at La Ciotat, The Lumière Brothers, 1896 in 4K resolution and 60 fps.

L'arrivée d'un train en gare de La Ciotat (translated from French into English as The Arrival of a Train at La Ciotat Station, Arrival of a Train at La Ciotat (US) and The Arrival of the Mail Train, and in the United Kingdom the film is known as Train Pulling into a Station) is an 1895 French short black-and-white silent documentary film directed and produced by Auguste and Louis Lumière. Contrary to myth, it was not shown at the Lumières' first public film screening on 28 December 1895 in Paris, France: the programme of ten films shown that day makes no mention of it. Its first public showing took place in January 1896.

L'Arrivée d'un train en gare de La Ciotat, ou L'Arrivée d'un train à La Ciotat, est un film français réalisé par Louis Lumière en 1895, sorti en, dont il existe plusieurs versions.


Types of compressors.

The main and important types of gas compressors are illustrated and discussed below:

Positive displacement.

A positive displacement compressor is the system which compresses the air by the displacement of a mechanical linkage reducing the volume (since the reduction in volume due to a piston in thermodynamics is considered as positive displacement of the piston).  Put another way, a positive displacement compressor is one which operates by drawing in a discrete volume of gas from its inlet then forcing that gas to exit via the compressor's outlet. The increase in the pressure of the gas is due, at least in part, to the compressor pumping it at a mass flow rate which cannot pass through the outlet at the lower pressure and density of the inlet.

Reciprocating compressors.

Reciprocating compressors use pistons driven by a crankshaft. They can be either stationary or portable, can be single or multi-staged, and can be driven by electric motors or internal combustion engines. Small reciprocating compressors from 5 to 30 horsepower (hp) are commonly seen in automotive applications and are typically for intermittent duty. Larger reciprocating compressors well over are commonly found in large industrial and petroleum applications. Discharge pressures can range from low pressure to very high pressure (>18000 psi or 180 MPa). In certain applications, such as air compression, multi-stage double-acting compressors are said to be the most efficient compressors available, and are typically larger, and more costly than comparable rotary units. Another type of reciprocating compressor, usually employed in automotive cabin air conditioning systems, is the swash plate or wobble plate compressor, which uses pistons moved by a swash plate mounted on a shaft (see "axial piston pump").  Household, home workshop, and smaller job site compressors are typically reciprocating compressors 11⁄2 hp or less with an attached receiver tank.  A linear compressor is a reciprocating compressor with the piston being the rotor of a linear motor.  This type of compressor can compress a wide range of gases, including refrigerant, hydrogen, and natural gas. Because of this, it finds use in a wide range of applications in many different industries and can be designed to a wide range of capacities, by varying size, number of cylinders, and cylinder unloading. However, it suffers from higher losses due to clearance volumes, resistance due to discharge and suction valves, weighs more, is difficult to maintain due to having a large number of moving parts, and it has inherent vibration.

Ionic liquid piston compressor.

An ionic liquid piston compressor, "ionic compressor" or "ionic liquid piston pump" is a hydrogen compressor based on an ionic liquid piston instead of a metal piston as in a piston-metal diaphragm compressor.

Rotary screw compressors.

Rotary screw compressors use two meshed rotating positive-displacement helical screws to force the gas into a smaller space. These are usually used for continuous operation in commercial and industrial applications and may be either stationary or portable. Their application can be from to over and from low pressure to moderately high pressure (>).  The classifications of rotary screw compressors vary based on stages, cooling methods, and drive types among others. Rotary screw compressors are commercially produced in Oil Flooded, Water Flooded and Dry type. The efficiency of rotary compressors depends on the air drier, and the selection of air drier is always 1.5 times volumetric delivery of the compressor.  Designs with a single screw or three screws instead of two exist.  Screw compressors have less components and a simpler structure, larger capacity, higher efficiency, less vibration and surging, can operate at lower speeds for capacity adjustment, but small sizes are impractical due to inherent leaks between the compression cavities and the casing of the compressor.

Rotary vane compressors.

Rotary vane compressors consist of a rotor with a number of blades inserted in radial slots in the rotor. The rotor is mounted offset in a larger housing that is either circular or a more complex shape. As the rotor turns, blades slide in and out of the slots keeping contact with the outer wall of the housing. Thus, a series of increasing and decreasing volumes is created by the rotating blades. Rotary Vane compressors are, with piston compressors one of the oldest of compressor technologies.  With suitable port connections, the devices may be either a compressor or a vacuum pump. They can be either stationary or portable, can be single or multi-staged, and can be driven by electric motors or internal combustion engines. Dry vane machines are used at relatively low pressures (e.g., ) for bulk material movement while oil-injected machines have the necessary volumetric efficiency to achieve pressures up to about in a single stage. A rotary vane compressor is well suited to electric motor drive and is significantly quieter in operation than the equivalent piston compressor.  Rotary vane compressors can have mechanical efficiencies of about 90%.

Rolling piston.

The Rolling piston in a rolling piston style compressor plays the part of a partition between the vane and the rotor. Rolling piston forces gas against a stationary vane.  2 of these compressors can be mounted on the same shaft to increase capacity and reduce vibration and noise. A design without a spring is known as a swing compressor.  In refrigeration and air conditioning, this type of compressor is also known as a rotary compressor, with rotary screw compressors being also known simply as screw compressors.  It offers higher efficiency than reciprocating compressors due to less losses from the clearance volume between the piston and the compressor casing, its 40% to 50% smaller and lighter for a given capacity (which can impact material and shipping costs when used in a product), causes less vibration, has fewer components and is more reliable than a reciprocating compressor. But its structure does not allow capacities beyond 5 refrigeration tons, is less reliable than other compressor types, and is less efficient than other compressor types due to losses from the clearance volume.

Scroll compressors.

A scroll compressor, also known as scroll pump and scroll vacuum pump, uses two interleaved spiral-like vanes to pump or compress fluids such as liquids and gases. The vane geometry may be involute, archimedean spiral, or hybrid curves. They operate more smoothly, quietly, and reliably than other types of compressors in the lower volume range.  Often, one of the scrolls is fixed, while the other orbits eccentrically without rotating, thereby trapping and pumping or compressing pockets of fluid between the scrolls.  Due to minimum clearance volume between the fixed scroll and the orbiting scroll, these compressors have a very high volumetric efficiency.  These compressors are extensively used in air conditioning and refrigeration because they are lighter, smaller and have fewer moving parts than reciprocating compressors and they are also more reliable. They are more expensive though, so peltier coolers or rotary and reciprocating compressors may be used in applications where cost is the most important or one of the most important factors to consider when designing a refrigeration or air conditioining system.  This type of compressor was used as the supercharger on Volkswagen G60 and G40 engines in the early 1990s.  When compared with reciprocating and rolling piston compressors, scroll compressors are more reliable since they have fewer components and have a simpler structure, is more efficient since they have no clearance volume nor valves, has less surging and it doesn't vibrate as much. But, when compared with screw and centrifugal compressors, scroll compressors have lower efficiencies and smaller capacities.

Diaphragm compressors.

A diaphragm compressor (also known as a membrane compressor) is a variant of the conventional reciprocating compressor. The compression of gas occurs by the movement of a flexible membrane, instead of an intake element. The back and forth movement of the membrane is driven by a rod and a crankshaft mechanism. Only the membrane and the compressor box come in contact with the gas being compressed.  The degree of flexing and the material constituting the diaphragm affects the maintenance life of the equipment. Generally stiff metal diaphragms may only displace a few cubic centimeters of volume because the metal can not endure large degrees of flexing without cracking, but the stiffness of a metal diaphragm allows it to pump at high pressures. Rubber or silicone diaphragms are capable of enduring deep pumping strokes of very high flexion, but their low strength limits their use to low-pressure applications, and they need to be replaced as plastic embrittlement occurs.  Diaphragm compressors are used for hydrogen and compressed natural gas (CNG) as well as in a number of other applications. The photograph on the right depicts a three-stage diaphragm compressor used to compress hydrogen gas to for use in a prototype compressed hydrogen and compressed natural gas (CNG) fueling station built in downtown Phoenix, Arizona by the Arizona Public Service company (an electric utilities company). Reciprocating compressors were used to compress the natural gas. The reciprocating natural gas compressor was developed by Sertco.  The prototype alternative fueling station was built in compliance with all of the prevailing safety, environmental and building codes in Phoenix to demonstrate that such fueling stations could be built in urban areas.

Dynamic.

Air bubble compressor.

Also known as a trompe. A mixture of air and water generated through turbulence is allowed to fall into a subterranean chamber where the air separates from the water. The weight of falling water compresses the air in the top of the chamber. A submerged outlet from the chamber allows water to flow to the surface at a lower height than the intake. An outlet in the roof of the chamber supplies the compressed air to the surface. A facility on this principle was built on the Montreal River at Ragged Shutes near Cobalt, Ontario in 1910 and supplied 5,000 horsepower to nearby mines.

Centrifugal compressors.

Centrifugal compressors use a rotating disk or impeller in a shaped housing to force the gas to the rim of the impeller, increasing the velocity of the gas. A diffuser (divergent duct) section converts the velocity energy to pressure energy. They are primarily used for continuous, stationary service in industries such as oil refineries, chemical and petrochemical plants and natural gas processing plants. Their application can be from to thousands of horsepower. With multiple staging, they can achieve high output pressures greater than.  This type of compressor, along with screw compressors, are extensively used in large refrigeration and air conditioning systems. Magnetic bearing (magnetically levitated) and air bearing centrifugal compressors exist.  Many large snowmaking operations (like ski resorts) use this type of compressor. They are also used in internal combustion engines as superchargers and turbochargers. Centrifugal compressors are used in small gas turbine engines or as the final compression stage of medium-sized gas turbines.  Centrifugal compressors are the largest available compressors, offer higher efficiencies under partial loads, may be oil-free when using air or magnetic bearings which increases the heat transfer coefficient in evaporators and condensers, weigh up to 90% less and occupy 50% less space than reciprocating compressors, are reliable and cost less to mantain since less components are exposed to wear, and only generate minimal vibration. But, their initial cost is higher, require highly precise CNC machining, the impeller needs to rotate at high speeds making small compressors impractical, and surging becomes more likely. Surging is gas flow reversal, meaning that the gas goes from the discharge to the suction side, which can cause serious damage, specially in the compressor bearings and its drive shaft. It is caused by a pressure on the discharge side that is higher than the output pressure of the compressor. This can cause gases to flow back and forth between the compressor and whatever is connected to its discharge line, causing oscillations.

Diagonal or mixed-flow compressors.

Diagonal or mixed-flow compressors are similar to centrifugal compressors, but have a radial and axial velocity component at the exit from the rotor. The diffuser is often used to turn diagonal flow to an axial rather than radial direction. Comparative to the conventional centrifugal compressor (of the same stage pressure ratio), the value of the speed of the mixed flow compressor is 1.5 times larger.

Axial compressors.

Axial compressors are dynamic rotating compressors that use arrays of fan-like airfoils to progressively compress a fluid. They are used where high flow rates or a compact design are required.  The arrays of airfoils are set in rows, usually as pairs: one rotating and one stationary. The rotating airfoils, also known as blades or "rotors", accelerate the fluid. The stationary airfoils, also known as "stators" or vanes, decelerate and redirect the flow direction of the fluid, preparing it for the rotor blades of the next stage. Axial compressors are almost always multi-staged, with the cross-sectional area of the gas passage diminishing along the compressor to maintain an optimum axial Mach number. Beyond about 5 stages or a 4:1 design pressure ratio a compressor will not function unless fitted with features such as stationary vanes with variable angles (known as variable inlet guide vanes and variable stators), the ability to allow some air to escape part-way along the compressor (known as interstage bleed) and being split into more than one rotating assembly (known as twin spools, for example).  Axial compressors can have high efficiencies; around 90% polytropic at their design conditions. However, they are relatively expensive, requiring a large number of components, tight tolerances and high quality materials. Axial compressors are used in medium to large gas turbine engines, natural gas pumping stations, and some chemical plants.

Hermetically sealed, open, or semi-hermetic.

Compressors used in refrigeration systems are often described as being either hermetic, open, or semi-hermetic, to describe how the compressor and motor drive are situated in relation to the gas or vapor being compressed. The industry name for a hermetic is hermetically sealed compressor, while a semi-hermetic is commonly called a semi-hermetic compressor.  In hermetic and most semi-hermetic compressors, the compressor and motor driving the compressor are integrated, and operate within the pressurized gas envelope of the system. The motor is designed to operate in, and be cooled by, the refrigerant gas being compressed.  The difference between the hermetic and semi-hermetic, is that the hermetic uses a one-piece welded steel casing that cannot be opened for repair; if the hermetic fails it is simply replaced with an entire new unit. A semi-hermetic uses a large cast metal shell with gasketed covers with screws that can be opened to replace motor and compressor components.  The primary advantage of a hermetic and semi-hermetic is that there is no route for the gas to leak out of the system. Open compressors rely on shaft seals to retain the internal pressure, and these seals require a lubricant such as oil to retain their sealing properties.  An open pressurized system such as an automobile air conditioner can be more susceptible to leak its operating gases. Open systems rely on lubricant in the system to splash on pump components and seals. If it is not operated frequently enough, the lubricant on the seals slowly evaporates, and then the seals begin to leak until the system is no longer functional and must be recharged. By comparison, a hermetic or semi-hermetic system can sit unused for years, and can usually be started up again at any time without requiring maintenance or experiencing any loss of system pressure.  The disadvantage of hermetic compressors is that the motor drive cannot be repaired or maintained, and the entire compressor must be replaced if a motor fails. A further disadvantage is that burnt-out windings can contaminate whole systems, thereby requiring the system to be entirely pumped down and the gas replaced (This can also happen in semi hermetic compressors where the motor operates in the refrigerant). Typically, hermetic compressors are used in low-cost factory-assembled consumer goods where the cost of repair and labor is high compared to the value of the device, and it would be more economical to just purchase a new device or compressor. Semi-hermetic compressors are used in mid-sized to large refrigeration and air conditioning systems, where it is cheaper to repair the compressor rather than buying and installing a new one. A hermetic compressor is simpler and cheaper to build than a semi-hermetic compressor.  An advantage of open compressors is that they can be driven by non-electric power sources, such as an internal combustion engine or turbine. However, open compressors that drive refrigeration systems are generally not totally "maintenance-free" throughout the life of the system, since some gas leakage will occur over time.

Thermodynamics of gas compression.

Isentropic compressor.

A compressor can be idealized as internally reversible and adiabatic, thus an isentropic steady state device, meaning the change in entropy is 0. By defining the compression cycle as isentropic, an ideal efficiency for the process can be attained, and the ideal compressor performance can be compared to the actual performance of the machine. Isotropic Compression as used in ASME PTC 10 Code refers to a reversible, adiabatic compression process  Isentropic efficiency of Compressors:

Minimizing work required by a compressor.

Comparing reversible to irreversible compressors.

Comparison of the differential form of the energy balance for each device  Let formula_5 be heat, formula_6 be work, formula_7 be kinetic energy and formula_8 be potential energy. Actual Compressor:  Reversible Compressor:  The right hand side of each compressor type is equivalent, thus:  re-arranging:  By substituting the know equation formula_13 into the last equation and dividing both terms by T:  Furthermore, formula_15 and T is [absolute temperature] (formula_16) which produces:  formula_17  or  formula_18  Therefore, work-consuming devices such as pumps and compressors (work is negative) require less work when they operate reversibly.

Effect of cooling during the compression process.

isentropic process: involves no cooling,  polytropic process: involves some cooling  isothermal process: involves maximum cooling  By making the following assumptions the required work for the compressor to compress a gas from formula_19 to formula_20 is the following for each process:  Assumptions:  Isentropic (formula_23, where formula_24):  Polytropic (formula_26):  Isothermal (formula_28 or formula_29):  By comparing the three internally reversible processes compressing an ideal gas from formula_19 to formula_20, the results show that isentropic compression (formula_23) requires the most work in and the isothermal compression(formula_28 or formula_29) requires the least amount of work in. For the polytropic process (formula_26) work in decreases as the exponent, n, decreases, by increasing the heat rejection during the compression process. One common way of cooling the gas during compression is to use cooling jackets around the casing of the compressor.

Compressors in ideal thermodynamic cycles.

Ideal Rankine Cycle 1->2 Isentropic compression in a pump  Ideal Carnot Cycle 4->1 Isentropic compression  Ideal Otto Cycle 1->2 Isentropic compression  Ideal Diesel Cycle 1->2 Isentropic compression  Ideal Brayton Cycle 1->2 Isentropic compression in a compressor  Ideal Vapor-compression refrigeration Cycle 1->2 Isentropic compression in a compressor  NOTE: The isentropic assumptions are only applicable with ideal cycles. Real world cycles have inherent losses due to inefficient compressors and turbines. The real world system are not truly isentropic but are rather idealized as isentropic for calculation purposes.

Temperature.

Compression of a gas increases its temperature.  where or and  so  in which "p" is pressure, "V" is volume, "n" takes different values for different compression processes (see below), and 1 & 2 refer to initial and final states. with "T" and "T" in degrees Rankine or kelvins, "p" and "p" being absolute pressures and formula_43 ratio of specific heats (approximately 1.4 for air). The rise in air and temperature ratio means compression does not follow a simple pressure to volume ratio. This is less efficient, but quick. Adiabatic compression or expansion more closely model real life when a compressor has good insulation, a large gas volume, or a short time scale (i.e., a high power level). In practice there will always be a certain amount of heat flow out of the compressed gas. Thus, making a perfect adiabatic compressor would require perfect heat insulation of all parts of the machine. For example, even a bicycle tire pump's metal tube becomes hot as you compress the air to fill a tire. The relation between temperature and compression ratio described above means that the value of formula_44 for an adiabatic process is formula_45 (the ratio of specific heats).  For an isothermal process, formula_44 is 1, so the value of the work integral for an isothermal process is:  When evaluated, the isothermal work is found to be lower than the adiabatic work.

Staged compression.

In the case of centrifugal compressors, commercial designs currently do not exceed a compression ratio of more than 3.5 to 1 in any one stage (for a typical gas). Since compression raises the temperature, the compressed gas is to be cooled between stages making the compression less adiabatic and more isothermal. The inter-stage coolers typically result in some partial condensation that is removed in vapor-liquid separators.  In the case of small reciprocating compressors, the compressor flywheel may drive a cooling fan that directs ambient air across the intercooler of a two or more stage compressor.  Because rotary screw compressors can make use of cooling lubricant to reduce the temperature rise from compression, they very often exceed a 9 to 1 compression ratio. For instance, in a typical diving compressor the air is compressed in three stages. If each stage has a compression ratio of 7 to 1, the compressor can output 343 times atmospheric pressure (7 × 7 × 7 = 343 atmospheres). ()

Drive motors.

There are many options for the motor that powers the compressor:

Applications.

Gas compressors are used in various applications where either higher pressures or lower volumes of gas are needed:

A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. An air compressor is a specific type of gas compressor.

Un compresseur mécanique est un organe mécanique destiné à augmenter la pression d'un gaz, et donc son énergie. Il existe également des compresseurs sans aucun organe mécanique, ce sont les thermocompresseurs, plus communément appelés éjecteurs.


Biography.

Andrzej Żuławski was born in Lviv (formerly known as Lwów). He was an assistant of the filmmaker Andrzej Wajda.  When his second film "The Devil" was banned in Poland, he decided to move to France, where he made "" (1975) with Romy Schneider.  After returning to Poland he worked for two years on a film which the authorities did not allow him to finish ("On the Silver Globe"), based on a book by his great-uncle Jerzy Żuławski. Since then he lived and worked mostly in France, making art films.  Being a maverick who always defied mainstream commercialism, Żuławski enjoyed success mostly with the European art-house audiences. His wild, imaginative, and controversial pictures have received awards at various international film festivals. He also wrote the novels "Il était Un Verger", "Lity Bór" (a.k.a. "La Forêt Forteresse"), W Oczach Tygrysa, and Ogród Miłości.  In 2006 he was the Head of the Jury at the 28th Moscow International Film Festival.  Żuławski worked many times with composer Andrzej Korzyński, beginning in "The Third Part of the Night" (1971). Their last collaboration was for "Cosmos" (2015), which was also Żuławski's last film.  On 17 February 2016, Żuławski died at a hospital in Warsaw from cancer.

Personal life.

He had three sons from different relationships. Żuławski's ex-wife was Małgorzata Braunek, who was a Polish film and stage actress. Their son, Xawery, is also a film director.  He was in a relationship with the French actress Sophie Marceau for sixteen years, with whom he made four films over a 15-year period ("L'Amour braque", "My Nights Are More Beautiful Than Your Days", "La Note bleue", "Fidelity"). They had a son Vincent together. They broke up in 2001.

Andrzej Żuławski (; 22 November 1940 – 17 February 2016) was a Polish film director and writer. He was born in Lviv, Ukrainian SSR (now Ukraine). Żuławski often went against mainstream commercialism in his films, and enjoyed success mostly with European art-house audiences.

Andrzej Żuławski est un réalisateur de cinéma, metteur en scène de théâtre, scénariste et écrivain polonais, né le à Lwów et mort le à Varsovie.


Setting.

"Vampire: The Dark Ages" is set in medieval Europe in 1197, in the World of Darkness; the updated version "Dark Ages: Vampire" moves the timeline forward to 1230, and "Vampire: The Dark Ages Twentieth Anniversary Edition" further to 1242. Players take the roles of vampires, who believe themselves to have descended from the biblical Caine, the first murderer. Each vampire belongs to one of thirteen clans with different vampiric powers and weaknesses, and with different relationships with other clans. Vampires hold a lot of power, and humans know of their existence, unlike in the modern setting of ""; because cities were smaller in the time of "Vampire: The Dark Ages", however, it is more difficult for vampires to hide their activities, and they need to face enemies directly as they do not have access to modern technology. In addition to vampires, all other beings from the World of Darkness games appear in the "Dark Ages" setting, including werewolves, changelings, wraiths and mages.

Gameplay.

"Vampire: The Dark Ages" shares its basic Storyteller System gameplay system with the other "World of Darkness" games, and is compatible with "Vampire: The Masquerade".

History.

"Vampire: The Dark Ages" was published by White Wolf Publishing in March 1996 as the first in a line of "World of Darkness" games with historical settings, each based on previous games in the series; the series also included 1997's "" and 1998's "". An updated version titled "Dark Ages: Vampire" was released in 2002, and received supplements based on other "World of Darkness" games, including "" and "Dark Ages: Inquisitor" in 2002; "" in 2003; and "" in 2004. A further update of the core game, "Vampire Twentieth Anniversary Edition: The Dark Ages", was published by Onyx Path Publishing, and was funded through a Kickstarter campaign in 2014 and released on July 29, 2015.  The game was given a French translation and published in France by Hexagonal in November 1996; "Twentieth Anniversary Edition" also got Spanish and Spanish release by Arkhane Asylum Publishing and NoSoloRos in 2016 and 2017, respectively, both of which were financed through crowdfunding campaigns.  The game was novelized as the thirteen-part "Dark Ages Clan Novel" series, beginning in 2002.

Reception.

Andy Butcher of "Arcane" called "Vampire: The Dark Ages" a great game with a lot of potential for many different kinds of scenarios. He called its "moody" atmosphere one of the biggest achievements of the game, which was helped by the artwork in the rule book, and enjoyed the interaction between the medieval setting and the vampires. He did however criticize how the game does not clearly define the nature of its version of vampires and only describes the setting broadly, making the game more difficult to play unless players have experience with "Vampire: The Masquerade" and some knowledge of 12th century history. He appreciated the single-roll, dice-based system for determining whether attempted tasks succeed, describing it as "simple and elegant" for allowing degrees of success or failure, but also criticized the gameplay for having unclear combat rules, something he described as a recurring problem in "World of Darkness" games.  By 1998 White Wolf was facing continued economic problems, and was hitting a crisis. Of their last five "World of Darkness games" – the three historical games, and 1994's "" and 1995's "" – only "Vampire: The Dark Ages" sold well.

Vampire: The Dark Ages is a tabletop role-playing game published by White Wolf Publishing in March 1996. It is a spin-off from "", also published by White Wolf, which is set in modern times. An updated version, "Dark Ages: Vampire", was released in 2002, and a further update, "Vampire Twentieth Anniversary Edition: The Dark Ages", in 2015.

Vampire : L'Âge des Ténèbres est un jeu de rôle médiéval-fantastique, publié par White Wolf Publishing en 1996. Le jeu est basé sur le même système que "". "Vampire : l'Âge des Ténèbres" permet d'incarner également un vampire mais dans le "Monde des ténèbres" (notre monde en plus « gothique »), au Moyen Âge, vers 1230, ce qui fournit une approche du jeu assez différente.


Influence of the French Revolution.

Godefroy III (b. 1728, r. 1771, d. 1792), duke of Bouillon and prince of Turenne, favourable to the French Revolution, committed his duchy to the path of reform by an edict of 24 February 1790 and supported his "assemblée générale" (parliament) when it voted to abolish manorial and feudal rights on 26 May 1790.  On 23 March or 1 May 1792, the duchy became a constitutional monarchy, becoming occupied by the French Revolutionary Army the following 19 November. Duke Jacques Léopold, who had succeeded his father in December 1792 but lived at the Château de Navarre, near Évreux (the last dukes of Bouillon did not reside in their duchy), was arrested and imprisoned in France under The Terror on 7 February 1794; like his father, he was a French citizen, as well as prince of a sovereign state.

Proclamation of the Republic.

Noting that contact with the sovereign duke was temporarily impossible, on 24 April 1794 the "assemblée générale" convened a Special Meeting of the Representatives of the People (), which may have proclaimed a republic. Some sources believe, however, that the "assemblée générale" did not proclaim the end of the ducal monarchy, but only reaffirmed the "essential democratic and popular" state and the transfer of executive authority to an "ad hoc" Council of State, meaning the ducal monarchy would not have really ended. Subsequent official documents cease to refer to the duke, possibly due to his imprisonment in France. The territory was annexed to the French First Republic on 26 October 1795 (4 Brumaire, year IV in the French Revolutionary Calendar). Its land was divided between the départements of Forêts, Ardennes and Sambre-et-Meuse, but not before the "assemblée générale" publicly denounced the annexation.  From 10 December 1793 (10 Frimaire II) the duke had been deprived of rents from his estates under French decree. A decree of 22 March 1800 (1 Germinal VIII), after Napoléon's accession to the French throne, ended the sequester of the ducal estates and allowed him to regain possession. However, he was still obliged to pay the 25% of assessed value he had offered to pay, and woods larger than were returned to him only on a provisional basis. The loss of his income during the five years had left him with 3 million livres in debts, he was hounded by the tax collectors and his creditors, and his expenses exceeded current revenues by 200 000 francs every year. Jacques Léopold died, without issue, in February 1802 as "citoyen Léopold la Tour d'Auvergne".

After the war.

After the end of the French occupation in April 1814, the territory of the former duchy was occupied by the Allied Powers, the duchy was restored briefly, headed by a British admiral from Jersey, Philippe d'Auvergne, cousin of the ducal family, adopted by duke Godefroy, who had agreed with the "assemblée générale" as heir should Jacques Léopold die without issue.  At the Congress of Vienna, however, another of Godefroy's cousins, Charles Alain de Rohan, Prince of Guéméné, a major-general of the Imperial and Royal Austrian Army and a citizen of the Austrian Empire since 1808, challenged the validity of the succession and claimed the ducal throne for himself.  After several months of uncertainty, Article 69 of the Final Act of the Congress of Vienna established the integration of the duchy into the Grand Duchy of Luxembourg (in personal union with the United Kingdom of the Netherlands) as of 9 June 1815. The question of compensation for rights-holders and other ducal pretenders was not settled, however, and became a subject of legal dispute for over a decade; the princes of Guéméné now hold claim to the throne of the extinct duchy. The king of the Netherlands, as grand-duke of Luxembourg, took possession of the duchy on 22 July 1815.  As a part of the Belgian Revolution, Bouillon rose up in revolt from 30 October 1830, leading to the surrender of the castle garrison. Bouillon, with the French-speaking grand-ducal territories, became part of Belgium (as the province of Luxembourg), with Belgium becoming "de facto" independent from the Kingdom of the Netherlands. The Treaty of the XXIV Articles, signed 15 November 1831 but only ratified in 1839 by all parties, recognised the "de jure" independence of Belgium, subsequently reinforced by Treaties of London in 1839 and in 1867.

The Republic of Bouillon was a short-lived French client republic, around the city of Bouillon in present-day Belgium, based on the duchy of Bouillon, which had existed between France and the Austrian Netherlands since the 15th century. Reforms, sponsored by the duke, abolishing manorialism and feudalism and establishing a constitutional basis for the monarchy did not prevent what many sources describe as the proclamation of a republic in April 1794. The republic was short-lived, however, as the territory was annexed by the French First Republic 18 months later. In 1815, after the Napoleonic Wars, the duchy was absorbed into the promoted Grand Duchy of Luxembourg, becoming a part of Belgium when that nation was founded in the 1830s.

La république bouillonnaise, ou république de Bouillon, est un État éphémère créé à la suite du duché de Bouillon, aux confins de la France et des Pays-Bas autrichiens (actuelle Belgique), d’avril 1794 à octobre 1795. Il compte 12 000 habitants en 1790.


Lieutenant to the Duke of Mayenne.

Mayenne was the second son of Francis of Lorraine, Duke of Guise and Anna d'Este, the daughter of Ercole II d'Este, Duke of Ferrara and Renée of France. By 1570, he was pressuring his brother, Henry, to buy him a house in Paris and had taken the dangerous habit of wearing the color green which represented the House of Anjou, the current heir to the throne. In 1572, Mayenne left France, without royal dispensation, to fight the Ottoman Turks in Greece.  Mayenne took part in the siege of La Rochelle, and was elevated from marquis to duke and peer of France that same year. He went with Henry of Valois, Duke of Anjou (later Henry III of France), on his election as king of Poland, but soon returned to France to become the energetic supporter and lieutenant of his brother, Henry I, Duke of Guise.  In 1576, at the head of an unpaid royal army, Mayenne was unable to deter the 25,000 German army under John Casimir from reaching Moulins on 4 March. He gained conspicuous successes over the Huguenot forces in Poitou in 1577. After Henry III of France signed the Edict of Beaulieu, Mayenne was forced to swear to support the edict, due to the suspicion of him being the leader of the League of Peronne.  As governor of Burgundy, Mayenne raised the province in the cause of the Catholic League in 1585. After the death of the heir to the throne, Francis, Duke of Anjou, on 10 June 1584, Mayenne and his brother, Henry, founded an association to keep Henry of Navarre from the throne of France. Mayenne, following his brother lead, captured Dijon, Macon and Auxonne.  The assassination of his brother, Henry, at Blois on 23–24 December 1588 left Mayenne at the head of the Catholic party.

Head of the Catholic League.

The ambassador of the Republic of Venice, Giovanni Mocenigo, states that Mayenne had warned Henry III that there was a plot afoot to seize his person and to send him by force to Paris. At the time of the murder he was at Lyon, where he received a letter from the king saying that he had acted on his warning, and ordering him to retire to his government.  Mayenne professed obedience, but immediately made preparations for marching on Paris. After a vain attempt to recover those of his relatives who had been arrested at Blois, he proceeded to recruit troops in his government of Burgundy and in Champagne. Paris was devoted to the house of Guise and had been roused to fury by the news of the murder. Mayenne entered Gournay-sur-Marne in 1589, while Paris would not fall until 1590. He found it dominated by representatives of the sixteen quarters of Paris, all staunch supporters of the League.  He formed a council general to direct the affairs of the city and to maintain relations with the other towns faithful to the League. Each quarter sent four representatives, and Mayenne added representatives of the various trades and professions of Paris in order to counterbalance this revolutionary element. He constituted himself "lieutenant-general of the state and crown of France," taking his oath before the parlement of Paris.  In April Mayenne advanced on Tours. Henry III in his extremity sought an alliance with the Huguenot, Henry of Navarre (the future Henry IV of France), and the allied forces drove the leaguers back, and had laid siege to Paris when the assassination of Henry III by a Dominican friar changed the face of affairs and gave new strength to the Catholic party.

King-maker.

Mayenne was urged to claim the crown for himself, but he was faithful to the official programme of the League and proclaimed Charles, Cardinal de Bourbon, at that time a prisoner in the hands of Henry IV, as Charles X of France, although this numbering is not accepted by historians. Henry IV retired to Dieppe, followed by Mayenne, who joined his forces with those of his cousin Charles, Duke of Aumale, and Charles II de Cossé, comte de Brissac, in a succession of fights in the neighbourhood of Arques (September 1589). He was defeated and out-marched by Henry IV, who moved on Paris, but retreated before Mayenne's forces.  In 1590 Mayenne received additions to his army from the Spanish Netherlands, and took the field again, only to suffer complete defeat at Ivry (14 March 1590). He then escaped to Mantes and in September collected a fresh army at Meaux, and with the assistance of Alexander Farnese, Duke of Parma, sent by Philip II of Spain, raised the siege of Paris, which was about to surrender to Henry IV. Mayenne feared with reason the designs of Philip II, and his difficulties were increased by the death of the Cardinal, the "king of the league."

Peacemaker.

The extreme section of the party, represented by the radical "Paris Sixteen", urged him to proceed to the election of a Catholic king and to accept the help and the claims of their Spanish Habsburg allies. Mayenne lacked the popular gifts of his brother, the Duke of Guise, and had no sympathy with the urban demagogues, inclining to the moderate side of his party, which began to urge reconciliation with Henry IV. He maintained the ancient forms of the constitution against the revolutionary policy of the Sixteen, who during his absence from Paris took the law into their own hands and in November 1591 executed one of the leaders of the more moderate party, Barnabé Brisson, president of the "parlement". He returned to Paris and executed four of the chief malcontents. The power of the Sixteen diminished from that time, and with it the strength of the League.  Mayenne entered into negotiations with Henri IV while he was still appearing to consider with Philip II the succession to the French crown of the Infanta Isabella Clara Eugenia of Spain, daughter of Elizabeth of Valois and granddaughter of Henri II. He demanded that Henri IV complete his conversion to Catholicism before he was recognized by the adherents of the League. He also desired the continuation to himself of the high offices which had accumulated in his family and the reservation of their provinces to his relatives among the Leaguers.  In 1593 he summoned the States-General to Paris and placed before them the claims of the Infanta, but they protested against foreign intervention. Mayenne signed a truce at La Villette on 31 July 1593. The internal dissensions of the league continued to increase, and the principal chiefs submitted. In 1595, Mayenne and Juan Fernández de Velasco moved to take Dijon with a Catholic League army. They were defeated by King Henry IV at Fontaine-Française, 6 June 1595. Mayenne finally made his peace only in October 1595. Henri IV allowed him the possession of Chalon-sur-Saône, of Seurre and Soissons for three years, made his son Henry governor of the Île-de-France and paid a large indemnity.

Marriage and children.

On 6 August 1576, Charles married Henriette of Savoy, Marquise of Villars, daughter of Honorat II of Savoy. They had:

Charles of Lorraine, Duke of Mayenne (26 March 1554 – 3 October 1611), or Charles de Guise, was a French nobleman of the house of Guise and a military leader of the Catholic League, which he headed during the French Wars of Religion, following the assassination of his brothers at Blois in 1588. In 1596, when he made peace with Henry IV of France, the wars were essentially at an end.

Charles (II) de Lorraine, duc de Mayenne ( à Alençon - à Soissons), est un noble français de la maison de Guise et un chef militaire de la Ligue pendant les guerres de Religion.


Background.

By the end of the 8th century, Muslim forces had conquered and settled most of the Iberian Peninsula. Under Islamic law, the Jews who had lived in the region since at least Roman times, were considered "People of the Book," which was a protected status. Compared to the repressive policies of the Visigothic Kingdom, who, starting in the sixth-century had enacted a series of anti-Jewish statutes which culminated in their forced conversion and enslavement, the tolerance of the Muslim Moorish rulers of "al-Andalus" allowed Jewish communities to thrive. Jewish merchants were able to trade freely across the Islamic world, which allowed them to flourish, and made Jewish enclaves in Muslim Iberian cities great centers of learning and commerce. This led to a flowering of Jewish culture, as Jewish scholars were able to gain favor in Muslim courts as skilled physicians, diplomats, translators, and poets. Although Jews never enjoyed equal status to Muslims, in some Taifas, such as Granada, Jewish men were appointed to very high offices, including Grand Vizier.  The "Reconquista", or the gradual reconquest of Muslim Iberia by the Christian kingdoms in the North, was driven by a powerful religious motivation: to reclaim Iberia for Christendom following the Umayyad conquest of Hispania centuries before. By the 14th century, most of the Iberian Peninsula (present-day Spain and Portugal) had been reconquered by the Christian kingdoms of Castile, Aragon, León, Galicia, Navarre, and Portugal.  During the Christian re-conquest, the Muslim kingdoms in Spain became less welcoming to the "dhimmi". In the late twelfth century, the Muslims in al-Andalus invited the fanatical Almohad dynasty from North Africa to push the Christians back to the North. After they gained control of the Iberian Peninsula, the Almohads offered the Sephardim a choice between expulsion, conversion, and death. Many Jewish people fled to other parts of the Muslim world, and also to the Christian kingdoms, which initially welcomed them. In Christian Spain, Jews functioned as courtiers, government officials, merchants, and moneylenders. Therefore, the Jewish community was both useful to the ruling classes and to an extent protected by them.  As the Reconquista drew to a close, overt hostility against Jews in Christian Spain became more pronounced, finding expression in brutal episodes of violence and oppression. In the early fourteenth century, the Christian kings vied to prove their piety by allowing the clergy to subject the Jewish population to forced sermons and disputations. More deadly attacks came later in the century from mobs of angry Catholics, led by popular preachers, who would storm into the Jewish quarter, destroy synagogues, and break into houses, forcing the inhabitants to choose between conversion and death. Thousands of Jews sought to escape these attacks by converting to Christianity. These Jewish converts were commonly called "conversos", New Christians, or "marranos"; the latter two terms were used as insults. At first, these conversions seemed an effective solution to the cultural conflict: many "converso" families met with social and commercial success. But eventually their success made these new Catholics unpopular with their neighbors, including some of the clergy of the Church and Spanish aristocrats competing with them for influence over the royal families. By the mid-fifteenth century, the demands of the Old Christians, that the Catholic Church and the monarchy differentiate them from the conversos, led to the first "limpieza de sangre" laws, which restricted opportunities for converts.  These suspicions on the part of Christians were only heightened by the fact that some of the coerced conversions were undoubtedly insincere. Some, but not all, "conversos" had understandably chosen to salvage their social and commercial positions or their lives by the only option open to them – baptism and embrace of Christianity – while privately adhering to their Jewish practice and faith. Recently converted families who continued to intermarry were especially viewed with suspicion. These secret practitioners are commonly referred to as crypto-Jews or "marranos".  The existence of crypto-Jews was a provocation for secular and ecclesiastical leaders who were already hostile toward Spain's Jewry. For their part, the Jewish community viewed conversos with compassion, because Jewish law held that conversion under threat of violence was not necessarily legitimate. Although the Catholic Church was also officially opposed to forced conversion, under ecclesiastical law all baptisms were lawful, and once baptized, converts were not allowed to rejoin their former religion. The uncertainty over the sincerity of Jewish converts added fuel to the fire of antisemitism in 15th century Spain.

European context.

From the 13th to the 16th centuries, European countries expelled the Jews from their territories on at least fifteen occasions. Before the Spanish expulsion, the Jews had been expelled from England in 1290, several times from France between 1182 and 1354, and from some German states. The French case is typical of most expulsions: whether the expulsion was local or national, the Jews usually were allowed to return after a few years. The Spanish expulsion was succeeded by at least five expulsions from other European countries, but the expulsion of the Jews from Spain was both the largest of its kind and, officially, the longest lasting in western European history.  Over the four-hundred-year period during which most of these decrees were implemented, the causes of expulsion gradually changed. At first, expulsions of Jews (or absence of expulsions) were exercises of royal prerogatives. Jewish communities in mediaeval Europe often were protected by and associated with monarchs because, under the feudal system, Jews often were a monarch's only reliable source of taxes. Jews further had reputations as moneylenders because they were the only social group allowed to loan money at a profit under the prevailing interpretation of the Vulgate (the Latin translation of the Bible used in Roman Catholic western Europe as the official text), which forbade Christians to charge interest on loans. Jews, therefore, became the lenders to and creditors of merchants, aristocrats, and even monarchs. Most expulsions before the Alhambra Decree were related to this financial situation: to raise additional monies, a monarch would tax the Jewish community heavily, forcing Jews to call in loans; the monarch then would expel the Jews; at the time of expulsion, the monarch would seize their remaining valuable assets, including debts owed them by other subjects of the monarch and, in some instances, by the monarch himself. Expulsion of the Jews from Spain was thus an innovation not only in scale but also in its motivations.

Ferdinand and Isabella.

Hostility towards the Jews in Spain was brought to a climax during the reign of the "Catholic Monarchs," Ferdinand and Isabella. Their marriage in 1469, which formed a personal union of the crowns of Aragon and Castile, with coordinated policies between their distinct kingdoms, eventually led to the final unification of Spain.  Although their initial policies towards the Jews were protective, Ferdinand and Isabella were disturbed by reports claiming that most Jewish converts to Christianity were insincere in their conversion. As mentioned above, some claims that "conversos" continued to practice Judaism in secret (see Crypto-Judaism) were true, but the "Old" Christians exaggerated the scale of the phenomenon. It was also claimed that Jews were trying to draw conversos back into the Jewish fold. In 1478, Ferdinand and Isabella made a formal application to Rome to set up an Inquisition in Castile to investigate these and other suspicions. In 1487, King Ferdinand promoted the establishment of the Spanish Inquisition Tribunals in Castile. In the Crown of Aragon, it had been first instituted in the 13th century to combat the Albigense heresy. However, the focus of this new Inquisition was to find and punish "conversos" who were practicing Judaism in secret.  These issues came to a head during Ferdinand and Isabella's final conquest of Granada. The independent Islamic Emirate of Granada had been a tributary state to Castile since 1238. Jews and conversos played an important role during this campaign because they had the ability to raise money and acquire weapons through their extensive trade networks. This perceived increase in Jewish influence further infuriated the Old Christians and the hostile elements of the clergy. Finally, in 1491 in preparation for an imminent transition to Castilian territory, the Treaty of Granada was signed by Emir Muhammad XII and the Queen of Castile, protecting the religious freedom of the Muslims there. By 1492, Ferdinand and Isabella had won the Battle of Granada and completed the Catholic Reconquista of the Iberian Peninsula from Islamic forces. However, the Jewish population emerged from the campaign more hated by the populace and less useful to the monarchs.

Decree.

The king and queen issued the Alhambra Decree less than three months after the surrender of Granada. Although Isabella was the force behind the decision, her husband Fernando did not oppose it, and both proved skillful at exploiting the hopes of the desperate Jewish population for monetary gain. That her confessor had just changed from the tolerant Hernando de Talavera to the very intolerant Francisco Jiménez de Cisneros suggests an increase in royal hostility towards the Jews. The text of the decree accused the Jews of trying "to subvert the holy Catholic faith" by attempting to "draw faithful Christians away from their beliefs." These measures were not new in Europe.  After the decree was passed, Spain's entire Jewish population was given only four months to either convert to Christianity or leave the country. The edict promised the Jews' royal "protection and security" for the effective three-month window before the deadline. They were permitted to take their belongings with them, excluding "gold or silver or minted money or other things prohibited by the laws of our kingdoms." In practice, however, the Jews had to sell anything they could not carry: their land, their houses, and their libraries, and converting their wealth to a more portable form proved difficult. The market in Spain was saturated with these goods, which meant the prices were artificially lowered for the months before the deadline. As a result, much of the wealth of the Jewish community remained in Spain. The punishment for any Jew who did not convert or leave by the deadline was summary execution.

Dispersal.

The Sephardic Jews migrated to four major areas: North Africa, the Ottoman Empire, Portugal, and Italy. Some Spanish Jews who emigrated to avoid conversion dispersed throughout the region of North Africa known as the Maghreb. The Jewish scholars and physicians among previous Sephardic immigrants to this area had reinvigorated the Jewish communities in North Africa. However, in the 1490s, parts of the Mediterranean world, including Morocco were experiencing severe famine. As a result, a number of cities in Morocco refused to let the Spanish Jews in. This led to mass starvation among the refugees, and made the Jewish refugees vulnerable to the predation of slavers, although the regional ruler invalidated many of these sales within a few years. A good number of the Jews who had fled to North Africa returned to Spain and got converted. The Jews who stayed in North Africa often intermingled with the already existing Mizrahi Arabic or Berber speaking communities, becoming the ancestors of the Moroccan, Algerian, Tunisian and Libyan Jewish communities.  Many Spanish Jews also fled to the Ottoman Empire, where they were given refuge. Sultan Bayezid II of the Ottoman Empire, learning about the expulsion of Jews from Spain, dispatched the Ottoman Navy to bring the Jews safely to Ottoman lands, mainly to the cities of Thessaloniki (currently in Greece) and İzmir (currently in Turkey). Many of these Jews also settled in other parts of the Balkans ruled by the Ottomans such as the areas that are now Bulgaria, Serbia and Bosnia. Concerning this incident, Bayezid II is alleged to have commented, "those who say that Ferdinand and Isabella are wise are indeed fools; for he gives me, his enemy, his national treasure, the Jews."  A majority of Sephardim migrated to Portugal, where they gained only a few years of respite from persecution. About 600 Jewish families were allowed to stay in Portugal following an exorbitant bribe until the Portuguese king entered negotiations to marry the daughter of Ferdinand and Isabella. Caught between his desire for an alliance with Spain and his economic reliance on the Jews, Manuel I declared the Jewish community in Portugal (perhaps then some 10% of that country's population) Christians by royal decree unless they left the country. In return, he promised the Inquisition would not come to Portugal for 40 years. He then seized the Jews who tried to leave and had them forcibly baptized, after separating them from their children. It was years before the Jews who fled to Portugal were allowed to emigrate. When the ban was lifted, many of them fled to the Low Countries, or the Netherlands.  Throughout history, scholars have given widely differing numbers of Jews expelled from Spain. However, the figure is likely to be below the 100,000 Jews who had not yet converted to Christianity by 1492, possibly as low as 40,000. Such figures exclude the significant number of Jews who returned to Spain due to the hostile reception they received in their countries of refuge, notably Fes (Morocco). The situation of returnees was legalized with the Ordinance of 10 November 1492 which established that civil and church authorities should be witnesses to baptism and, in the case that they were baptized before arrival, proof and witnesses of baptism were required. Furthermore, all property could be recovered by returnees at the same price at which it was sold. Similarly the Provision of the Royal Council of 24 October 1493 set harsh sanctions for those who slandered these New Christians with insulting terms such as "tornadizos". After all, the Catholic monarchs were concerned with the souls of their subjects, and Catholic doctrine held that the persecution of converts would remove an important incentive for conversion. Returnees are documented as late as 1499.

Conversions.

A majority of Spain's Jewish population had converted to Christianity during the waves of religious persecutions prior to the Decree—a total of 200,000 converts according to Joseph Pérez. The main objective of the expulsion of practicing Jews was ensuring the sincerity of the conversions of such a large convert population. Of the 100,000 Jews that remained true to their faith by 1492, an additional number chose to convert and join the converso community rather than face expulsion. Recent conversos were subject to additional suspicion by the Inquisition, which had been established to persecute religious heretics, but in Spain and Portugal was focused on finding crypto-Jews. Although Judaism was not considered a heresy, professing Christianity while engaging in Jewish practices was heretical. Additionally, "Limpieza de sangre" statutes instituted legal discrimination against converso descendants, barring them from certain positions and forbidding them from immigrating to the Americas. For years, families with urban origins who had extensive trade connections, and people who were learned and multilingual were suspected of having Jewish ancestry. According to the prejudice of the time, a person with Jewish blood was untrustworthy and inferior. Such measures slowly faded away as converso identity was forgotten and this community merged into Spain's dominant Catholic culture. This process lasted until the eighteenth century, with a few exceptions, most notably the Chuetas of the island of Majorca, where discrimination lasted into early 20th Century.  A Y chromosome DNA test conducted by the University of Leicester and the Pompeu Fabra University has indicated an average of nearly 20% for Spaniards having some direct patrilineal descent from populations from the Near East which colonized the region either in historical times, such as Jews and Phoenicians, or during earlier prehistoric Neolithic migrations. Between the 90,000 Jews who converted under the Visigoth persecutions, and the 100,000+ Jews who converted in the years leading up to expulsion, it is likely that many of these people have Jewish ancestry. On the other hand, genetic studies have dispelled local beliefs in the American South West that Spanish Americans are the descendants of conversos.

Modern Spanish policy.

The Spanish government has actively pursued a policy of reconciliation with the descendants of its expelled Jews. In 1924, the regime of Primo de Rivera granted the possibility of obtaining Spanish citizenship to the entire Sephardic Jewish diaspora. As stated above, the Alhambra decree was officially revoked in 1968, after the Second Vatican Council rejected the charge of deicide traditionally attributed to the Jews. In 1992, in a ceremony marking the 500th anniversary of the Edict of Expulsion, King Juan Carlos (wearing a yarmulke) prayed alongside Israeli president Chaim Herzog and members of the Jewish community in the Beth Yaacov Synagogue. The King said, "Sefarad (the Hebrew name for Spain) isn't a nostalgic memory anymore; it is a place where it must not be said that Jews should simply 'feel' at home there, for indeed Hispano-Jews are at home in Spain...What matters is not accountability for what we may have done wrong or right, but the willingness to look to the future, and analyze the past in light of our future."  From November 2012 Sephardi Jews have had the right to automatic Spanish nationality without the requirement of residence in Spain. Prior to November 2012, Sephardi Jews already had the right to obtain Spanish citizenship after a reduced residency period of two years (versus ten years for foreigners but nationals from Philippines, Equatorial Guinea, Brazil and about other 20 American republics that also require 2 years.) While their citizenship is being processed, Sephardi Jews are entitled to the consular protection of the Kingdom of Spain. This makes Spain unique among European nations as the only nation that currently grants automatic citizenship to the descendants of Jews expelled during the European medieval evictions. Although these measures are popular in the Jewish community, they have also sparked some controversy. A minority of thinkers hold that these policies represent less the abnegation of prejudice as a shift to Philo-Semitism. As of November 2015, 4300 Sephardi Jews have benefited from this law and acquired Spanish citizenship, swearing allegiance to the Spanish Constitution. In 2013, the number of Jews in Spain was estimated to range between 40,000 and 50,000 people.

The Alhambra Decree (also known as the Edict of Expulsion; Spanish: "Decreto de la Alhambra, Edicto de Granada") was an edict issued on 31 March 1492, by the joint Catholic Monarchs of Spain (Isabella I of Castile and Ferdinand II of Aragon) ordering the expulsion of practicing Jews from the Crowns of Castile and Aragon and its territories and possessions by 31 July of that year. The primary purpose was to eliminate their influence on Spain's large "converso" population and ensure they did not revert to Judaism. Over half of Spain's Jews had converted as a result of the religious persecution and pogroms which occurred in 1391. Due to continuing attacks, around 50,000 more had converted by 1415. A further number of those remaining chose to convert to avoid expulsion. As a result of the Alhambra decree and persecution in prior years, over 200,000 Jews converted to Catholicism and between 40,000 and 100,000 were expelled, an unknown number returning to Spain in the years following the expulsion.

Le décret de l’Alhambra est l'édit d’expulsion des Juifs, signé le par les Rois catholiques à l’Alhambra de Grenade, trois mois après la prise de cette ville aux musulmans. Motivé par la volonté de christianiser totalement les Espagnes médiévales en prélude à leur unification, il entraîne, quatre mois plus tard, l’expulsion des Juifs d’Espagne.