document_title: American Made (film)

question_text: what kind of plane is in american made

question_tokens: what kind of plane is in american made

text: American Made (film)

text: Plot[edit]

text: In 1978, Baton Rouge pilot Barry Seal, who flies commercial jets for TWA, is recruited by a CIA case officer calling himself Monty Schafer. He asks Seal, who has been smuggling Cuban cigars into the country via Canada, to fly clandestine reconnaissance missions for the CIA over Central America using a small plane with cameras installed. At first Seal's wife Lucy thinks he's still with TWA, but eventually she is excited by the wealth generated by his "new company".

text: Later in the 1980s, Schafer asks Seal to start acting as a courier between the CIA and General Noriega in Panama. During a mission, the Medellín Cartel picks Seal up and asks him to fly cocaine on his return flights to the United States. Seal accepts and starts flying the cartel's cocaine to Louisiana. The CIA turns a blind eye to the drug smuggling, but the DEA tracks Seal down. To avoid the authorities, Schafer moves Seal and his family to the remote town of Mena, Arkansas.

text: Later, Schafer asks Seal to run guns to the Nicaraguan Contras based in Honduras, Central America. Seal soon realizes that the Contras are not serious about the war and just want to get rich and he starts trading the guns to the cartel. The CIA sets up a Contra training base in Mena and Seal flies the Contras in, but many of them escape as soon as they arrive.

text: Seal makes so much money he buries it in suitcases in the backyard. Seal's freeloading brother-in-law JB moves in, needing a job. Eventually, he starts stealing money from the Seals and is arrested after Sheriff Downing catches him with a briefcase full of laundered cash. With JB out on bail, Seal gives him money and a plane ticket to Bora Bora and tells him to get lost for his own safety. JB demands weekly cash and implies that he will snitch if he doesn't get paid off. Barry tries to reason with him but JB's car explodes in a fireball; the cartel of Jorge Ochoa isn't taking any chances.

text: Eventually, the CIA shuts the program down and abandons Seal, who is arrested by the FBI, DEA, ATF and Arkansas State Police simultaneously. Seal escapes prosecution by making a deal with the White House, which wants evidence the Sandinistas are drug traffickers. They ask Seal to get photos that tie the Medellín Cartel to the Nicaraguan Sandinistas. Seal manages to get the pictures, but the White House releases them as propaganda against the Sandinistas. Seal is prominently shown in the pictures, which leads to his arrest, and to the cartel plotting revenge.

text: Seal is convicted but given a light sentence, a total of 1,000 hours community service for the Salvation Army. Moving from motel to motel fails as a way of remaining in hiding because the community service is performed at the same building every night. Assassins sent by Pablo Escobar and the cartel easily locate Seal and kill him; the CIA then destroys all documentation and other evidence to avoid being implicated in drug smuggling. Even after Seal is dead and the evidence is destroyed, the CIA still becomes embroiled in the infamous Iran–Contra affair.

text: Cast[edit]

text:
Tom Cruise as Barry Seal
Sarah Wright as Lucy Seal
Domhnall Gleeson as Monty Schafer
Alejandro Edda as Jorge Ochoa
Benito Martinez as James Rangel
Mauricio Mejia as Pablo Escobar
Jayma Mays as Dana Sibota
Jesse Plemons as Sheriff Downing
Lola Kirke as Judy Downing
Frank Licari as ATF Special Agent Franks
Jed Rees as Louis Finkle
Caleb Landry Jones as JB
Connor Trinneer as George W. Bush
Robert P. Farrior as Oliver North

text: Production[edit]

text: Development[edit]

text: In the summer of 2013, screenwriter Gary Spinelli was looking for a project that was based on real events. On the bonus feature of American Made, Spinelli said:

text: I was looking for little hidden pieces of history. Small stories that affected larger global events and I came across the Mena story. And I always wanted to do a gangster film. Goodfellas is one of my favorite movies and I was always on the hunt to try to find my version of that. And once I started researching CIA's involvement in Mena, the same name kept popping up, was this Barry Seal character. As soon as I found Barry, I knew I had a movie.[7]

text: The film was originally titled Mena and was first featured on The Black List, a website showcasing the best unproduced screenplays, in 2014.[8]

text: Filming[edit]

text: Principal photography on the film began on May 27, 2015 in Georgia.[9] Filming locations there include counties Cherokee, Clayton, DeKalb, Fulton, Gwinnett, Morgan and Pickens.[9] On August 20, 2015, Tom Cruise arrived in Medellin, Colombia, and on August 31, in Santa Marta,[10] to scout filming locations for the film.[11]

text: Plane crash[edit]

text: A plane crash on the set of the film in Colombia on September 11, 2015 killed two people and caused serious injuries to another member of the crew. The plane (a twin-engine Piper Aerostar), which was carrying crew members (three American pilots), was returning to Enrique Olaya Herrera Airport in Medellín when it ran into bad weather and the crash occurred.[12] The dead were identified as Carlos Berl and Alan Purwin, who was the founder and president of Helinet Aviation, a company which provides aerial surveillance technology to government agencies and law enforcement, and a film pilot who had worked in top films. American pilot Jimmy Lee Garland was seriously injured and rushed to a local hospital.[13][14]

text: Release[edit]

text: In May 2015, Universal set the film for release on January 6, 2017.[15] On August 8, 2016, the film's release was pushed to September 29, 2017, and its title changed from Mena to American Made.[16] It was released in Europe on August 23, 2017, and in the United States on September 29, 2017, and also screened at the Deauville Film Festival on September 1, 2017.[17]

text: Reception[edit]

text: Box office[edit]

text: American Made grossed $51.3 million in the United States and Canada, and $83.6 million in other territories, for a worldwide total of $134.9 million, against a production budget of $50 million.[2]

text: In North America, American Made was released alongside the openings of Flatliners and 'Til Death Do Us Part, as well as the wide expansion of Battle of the Sexes, and was projected to gross $12–15 million from 3,023 theaters in its opening weekend.[18] It made $960,000 from Thursday night previews, the lowest total by a Cruise-led film in recent years, and $6.1 million on its first day. Initially, studio estimates had the film opening to $17 million, finishing third at the box office, behind holdovers It ($17.3 million) and Kingsman: The Golden Circle ($17 million). The following day, actual results had the film debuting to $16.8 million, with Kingsman beating out It by a gross of $16.93 million to $16.90 million. 91% of its opening weekend audience was over the age of 25.[19] In its second weekend, the film grossed $8.1 million (a drop of 51%), finishing 6th.[20]

text: The film was released in 21 countries on August 25, 2017, and grossed a total of $6.1 million over the weekend. It finished number one in 11 of the territories, including the U.K., where it replaced five-time champ Dunkirk.[21]

text: Critical response[edit]

text: On review aggregator website Rotten Tomatoes, the film holds an approval rating of 86% based on 240 reviews, and an average rating of 7/10. The site's critical consensus reads, "American Made's fast-and-loose attitude with its real-life story mirrors the cavalier – and delightfully watchable – energy Tom Cruise gives off in the leading role."[22] On Metacritic, which assigns a normalized rating to reviews, the film has a weighted average score of 65 out of 100, based on 50 critics, indicating "generally favorable reviews".[23] Audiences polled by CinemaScore gave the film an average grade of "B+" on an A+ to F scale, while PostTrak reported filmgoers gave it a 55% "definite recommend".[19]

text: Historical accuracy[edit]

text: Despite the film's suggestion that he was recruited by the CIA while working for TWA, Seal denied in court that he had ever worked for the CIA. Seal was fired from TWA in 1974 for falsely claiming medical leave when he was involved in a smuggling scheme. Monty Schafer was a fictional character and not based on a real-life CIA agent. Seal's connections with cartel bosses were also not direct when he was running his drug operations, and he did not meet Pablo Escobar and the Ochoa brothers in person until 1984, when he was working as an informant for the DEA on an undercover operation, following his arrest.[24]

text: His third wife Deborah, whom Lucy was loosely based on, stated that Seal started his drug smuggling business in 1975, not 1980 like the film suggests, and that it was centered around marijuana before it involved cocaine. Seal's DEA record also noted that he expanded to smuggling cocaine in 1978 and claimed that he was smuggling marijuana as early as 1976. Seal's ties to the Medellín Cartel also began not after being kidnapped while refueling his plane in Colombia, but when he met a smuggler who flew for cartel operative Jorge Ochoa during a flight home from Honduras, where he served nine months in a local jail after being caught smuggling drugs in 1979.[24]

text: When asked by Abraham Riesman of Vulture if the film was a biopic, director Doug Liman said "You know, we're not making a biopic. Tom Cruise doesn't look like Barry Seal. His character is inspired by the stories we learned about Barry."  It has been noted  the real Seal was not of Tom Cruise's 5-foot-7 frame, and was an obese man who reportedly weighed 300 pounds.[25] Liman has also acknowledged that the film's zero-gravity love scene was his idea, and that he received the inspiration for it after he and Cruise collided in the cockpit while filming a flight scene.[24]

text: Seal was unapologetic about his weapons and drug smuggling operations, even stating once in a television interview, "Whether you call it soldier of fortune or what, it's a way of life for me. I enjoy it and I'm going to keep doing it."[25] He also never crash-landed into a suburban neighborhood.[24] Liman has described the film as "a fun lie based on a true story."[25]


document_title: Infrared spectroscopy

question_text: 2. describe the conditions for ir absorption to occur

question_tokens: 2 . describe the conditions for ir absorption to occur

root

text: Infrared spectroscopy

text: Theory[edit]

text: Infrared spectroscopy exploits the fact that molecules absorb frequencies that are characteristic of their structure. These absorptions occur at resonant frequencies, i.e. the frequency of the absorbed radiation matches the vibrational frequency.  The energies are affected by the shape of the molecular potential energy surfaces, the masses of the atoms, and the associated vibronic coupling.

tag: p

text: In particular, in the Born–Oppenheimer and harmonic approximations, i.e. when the molecular Hamiltonian corresponding to the electronic ground state can be approximated by a harmonic oscillator in the neighborhood of the equilibrium molecular geometry, the resonant frequencies are associated with the normal modes corresponding to the molecular electronic ground state potential energy surface. The resonant frequencies are also related to the strength of the bond and the mass of the atoms at either end of it. Thus, the frequency of the vibrations are associated with a particular normal mode of motion and a particular bond type.

text: Number of vibrational modes[edit]

text: In order for a vibrational mode in a sample to be "IR active", it must be associated with changes in the dipole moment. A permanent dipole is not necessary, as the rule requires only a change in dipole moment.[1]

text: A molecule can vibrate in many ways, and each way is called a vibrational mode.  For molecules with N number of atoms, linear molecules have 3N – 5 degrees of vibrational modes, whereas nonlinear molecules have 3N – 6 degrees of vibrational modes (also called vibrational degrees of freedom). As an example H2O, a non-linear molecule, will have 3 × 3 – 6 = 3 degrees of vibrational freedom, or modes.

text: Simple diatomic molecules have only one bond and only one vibrational band. If the molecule is symmetrical, e.g. N2, the band is not observed in the IR spectrum, but only in the Raman spectrum.  Asymmetrical diatomic molecules, e.g. CO, absorb in the IR spectrum. More complex molecules have many bonds, and their vibrational spectra are correspondingly more complex, i.e. big molecules have many peaks in their IR spectra.

text: The atoms in a CH2X2 group, commonly found in organic compounds and where X can represent any other atom, can vibrate in nine different ways. Six of these vibrations involve only the CH2 portion: symmetric and antisymmetric stretching, scissoring, rocking, wagging and twisting, as shown below. Structures that do not have the two additional X groups attached have fewer modes because some modes are defined by specific relationships to those other attached groups. For example, in water, the rocking, wagging, and twisting modes do not exist because these types of motions of the H represent simple rotation of the whole molecule rather than vibrations within it.

text:
SymmetryDirection

Symmetric

Antisymmetric

Radial

Symmetric stretching

Antisymmetric stretching

Latitudinal

Scissoring

Rocking

Longitudal

Wagging

Twisting

tag: table

text: These figures do not represent the "recoil" of the C atoms, which, though necessarily present to balance the overall movements of the molecule, are much smaller than the movements of the lighter H atoms.

text: Special effects[edit]

text: The simplest and most important or fundamental IR bands arise from the excitations of normal modes, the simplest distortions of the molecule, from the ground state with vibrational quantum number v = 0 to the first excited state with vibrational quantum number v = 1. In some cases, overtone bands are observed. An overtone band arises from the absorption of a photon leading to a direct transition from the ground state to the second excited vibrational state (v = 2). Such a band appears at approximately twice the energy of the fundamental band for the same normal mode. Some excitations, so-called combination modes, involve simultaneous excitation of more than one normal mode. The phenomenon of Fermi resonance can arise when two modes are similar in energy; Fermi resonance results in an unexpected shift in energy and intensity of the bands etc.

text: Practical IR spectroscopy[edit]

text: The infrared spectrum of a sample is recorded by passing a beam of infrared light through the sample. When the frequency of the IR is the same as the vibrational frequency of a bond or collection of bonds, absorption occurs. Examination of the transmitted light reveals how much energy was absorbed at each frequency (or wavelength). This measurement can be achieved by scanning the wavelength range using a monochromator. Alternatively, the entire wavelength range is measured  using a Fourier transform instrument and then a transmittance or absorbance spectrum is generated using a dedicated procedure.

text: This technique is commonly used for analyzing samples with covalent bonds. Simple spectra are obtained from samples with few IR active bonds and high levels of purity. More complex molecular structures lead to more absorption bands and more complex spectra.

text: Sample preparation[edit]

text: Gaseous samples require a sample cell with a long pathlength to compensate for the diluteness. The pathlength of the sample cell depends on the concentration of the compound of interest. A simple glass tube with length of 5 to 10 cm equipped with infrared-transparent windows at the both ends of the tube can be used for concentrations down to several hundred ppm. Sample gas concentrations well below ppm can be measured with a  White's cell in which the infrared light is guided with mirrors to travel through the gas. White's cells are available with optical pathlength starting from 0.5 m up to hundred meters.

text:
Liquid samples can be sandwiched between two plates of a salt (commonly sodium chloride, or common salt, although a number of other salts such as potassium bromide or calcium fluoride are also used).[2]
The plates are transparent to the infrared light and do not introduce any lines onto the spectra.

text: Solid samples can be prepared in a variety of ways. One common method is to crush the sample with an oily mulling agent (usually mineral oil Nujol). A thin film of the mull is applied onto salt plates and measured. The second method is to grind a quantity of the sample with a specially purified salt (usually potassium bromide) finely (to remove scattering effects from large crystals). This powder mixture is then pressed in a mechanical press to form a translucent pellet through which the beam of the spectrometer can pass.[2]  A third technique is the "cast film" technique, which is used mainly for polymeric materials. The sample is first dissolved in a suitable, non hygroscopic solvent. A drop of this solution is deposited on surface of KBr or NaCl cell. The solution is then evaporated to dryness and the film formed on the cell is analysed directly. Care is important to ensure that the film is not too thick otherwise light cannot pass through. This technique is suitable for qualitative analysis. The final method is to use microtomy to cut a thin (20–100 µm) film from a solid sample. This is one of the most important ways of analysing failed plastic products for example because the integrity of the solid is preserved.

text: In photoacoustic spectroscopy the need for sample treatment is minimal. The sample, liquid or solid, is placed into the sample cup which is inserted into the photoacoustic cell which is then sealed for the measurement. The sample may be one solid piece, powder or basically in any form for the measurement. For example, a piece of rock can be inserted into the sample cup and the spectrum measured from it.

text: Comparing to a reference[edit]

text: It is typical to record spectrum of both the sample and a "reference". This step controls for a number of variables, e.g. infrared detector, which may affect the spectrum. The reference measurement makes it possible to eliminate the instrument influence.

text: The appropriate "reference" depends on the measurement and its goal. The simplest reference measurement is to simply remove the sample (replacing it by air). However, sometimes a different reference is more useful. For example, if the sample is a dilute solute dissolved in water in a beaker, then a good reference measurement might be to measure pure water in the same beaker. Then the reference measurement would cancel out not only all the instrumental properties (like what light source is used), but also the light-absorbing and light-reflecting properties of the water and beaker, and the final result would just show the properties of the solute (at least approximately).

text: A common way to compare to a reference is sequentially: first measure the reference, then replace the reference by the sample and measure the sample. This technique is not perfectly reliable; if the infrared lamp is a bit brighter during the reference measurement, then a bit dimmer during the sample measurement, the measurement will be distorted. More elaborate methods, such as a "two-beam" setup (see figure), can correct for these types of effects to give very accurate results. The Standard addition method can be used to statistically cancel these errors.

text: Nevertheless, among different absorption based techniques which are used for gaseous species detection, Cavity ring-down spectroscopy (CRDS) can be used as a calibration free method. The fact that CRDS is based on the measurements of photon life-times (and not the laser intensity) makes it needless for any calibration and comparison with a reference [3]

text: FTIR[edit]

text: Fourier transform infrared (FTIR) spectroscopy is a measurement technique that allows one to record infrared spectra.  Infrared light is guided through an interferometer and then through the sample (or vice versa).  A moving mirror inside the apparatus alters the distribution of infrared light that passes through the interferometer. The signal directly recorded, called an  "interferogram", represents light output as a function of mirror position. A data-processing technique called Fourier transform turns this raw data into the desired result (the sample's spectrum): Light output as a function of infrared wavelength (or equivalently, wavenumber). As described above, the sample's spectrum is always compared to a reference.

text: An alternate method for acquiring spectra is the "dispersive" or "scanning monochromator" method.  In this approach, the sample is irradiated sequentially with various single wavelengths. The dispersive method is more common in UV-Vis spectroscopy, but is less practical in the infrared than the FTIR method. One reason that FTIR is favored is called "Fellgett's advantage" or the "multiplex advantage": The information at all frequencies is collected simultaneously, improving both speed and signal-to-noise ratio. Another is called "Jacquinot's Throughput Advantage": A dispersive measurement requires detecting much lower light levels than an FTIR measurement.[4] There are other advantages, as well as some disadvantages,[4] but virtually all modern infrared spectrometers are FTIR instruments.

text: Absorption bands[edit]

text: IR spectroscopy is often used to identify structures because functional groups give rise to characteristic bands both in terms of intensity and position (frequency).  The positions of these bands are summarized in correlation tables as shown below.

text: Regions[edit]

text: A spectrograph is often interpreted as having two regions.[5]

text:
functional group region

≥
1500
c

m

−
1

{\displaystyle \geq 1500cm^{-1}}

tag: ul

text: In the functional region there are one to a few troughs per functional group.[5]

text:
fingerprint region

<
1500
c

m

−
1

{\displaystyle <1500cm^{-1}}

text: In the fingerprint region there are many troughs which form an intricate pattern which can be used like a fingerprint to determine the compound.[5]

text: Badger's rule[edit]

text: For many kinds of samples, the assignments are known, i.e. which bond deformation(s) are associated with which frequency.  In such cases further information can be gleaned about the strength on a bond, relying on the empirical guideline called Badger's Rule.  Originally published by Richard Badger in 1934,[6] this rule states that the strength of a bond correlates with the frequency of its vibrational mode. That is, increase in bond strength leads to corresponding frequency increase and vice versa.

text: Uses and applications[edit]

text: Infrared spectroscopy is a simple and reliable technique widely used in both organic and inorganic chemistry, in research and industry. It is used in quality control, dynamic measurement, and monitoring applications such as the long-term unattended measurement of CO2 concentrations in greenhouses and growth chambers by infrared gas analyzers.

text: It is also used in forensic analysis in both criminal and civil cases, for example in identifying polymer degradation. It can be used in determining the blood alcohol content of a suspected drunk driver.

text: IR-spectroscopy has been successfully used in analysis and identification of pigments in paintings[7] and other art objects[8] such as illuminated manuscripts.[9]

text: A useful way of analyzing solid samples without the need for cutting samples uses ATR or attenuated total reflectance spectroscopy. Using this approach, samples are pressed against the face of a single crystal. The infrared radiation passes through the crystal and only interacts with the sample at the interface between the two materials.

text: With increasing technology in computer filtering and manipulation of the results, samples in solution can now be measured accurately (water produces a broad absorbance across the range of interest, and thus renders the spectra unreadable without this computer treatment).

text: Some instruments will also automatically tell you what substance is being measured from a store of thousands of reference spectra held in storage.

text: Infrared spectroscopy is also useful in measuring the degree of polymerization in polymer manufacture. Changes in the character or quantity of a particular bond are assessed by measuring at a specific frequency over time. Modern research instruments can take infrared measurements across the range of interest as frequently as 32 times a second. This can be done whilst simultaneous measurements are made using other techniques. This makes the observations of chemical reactions and processes quicker and more accurate.

text: Infrared spectroscopy has also been successfully utilized in the field of semiconductor microelectronics:[10] for example, infrared spectroscopy can be applied to semiconductors like silicon, gallium arsenide, gallium nitride, zinc selenide, amorphous silicon, silicon nitride, etc.

text: Another important application of Infrared Spectroscopy is in the food industry to measure the concentration of various compounds in different food products[11][12]

text: The instruments are now small, and can be transported, even for use in field trials.

text: Infrared Spectroscopy is also used in gas leak detection devices such as the DP-IR and EyeCGAs.[13] These devices detect hydrocarbon gas leaks in the transportation of natural gas and crude oil.

text: In February 2014, NASA announced a greatly upgraded database, based on IR spectroscopy, for tracking polycyclic aromatic hydrocarbons (PAHs) in the universe. According to scientists, more than 20% of the carbon in the universe may be associated with PAHs, possible starting materials for the formation of life. PAHs seem to have been formed shortly after the Big Bang, are widespread throughout the universe, and are associated with new stars and exoplanets.[14]

text: Recent developments include a miniature IR-spectrometer that's linked to a cloud based database and suitable for personal everyday use,[15] and NIR-spectroscopic chips[16] that can be embedded in smartphones and various gadgets.

text: Isotope effects[edit]

text: The different isotopes in a particular species may exhibit different fine details in infrared spectroscopy. For example, the O–O stretching frequency (in reciprocal centimeters) of oxyhemocyanin is experimentally determined to be 832 and 788 cm−1 for ν(16O–16O) and ν(18O–18O), respectively.

text: By considering the O–O bond as a spring, the wavenumber of absorbance, ν can be calculated:

text: where k is the spring constant for the bond, c is the speed of light, and μ is the reduced mass of the A–B system:

text:
(

m

i

{\displaystyle m_{i}}

 is the mass of atom

i

{\displaystyle i}

).

text: The reduced masses for 16O–16O and 18O–18O can be approximated as 8 and 9 respectively. Thus

text:
Where

ν

{\displaystyle \nu }

 is the wavenumber; [wavenumber = frequency/(speed of light)]

text: The effect of isotopes, both on the vibration and the decay dynamics, has been found to be stronger than previously thought. In some systems, such as silicon and germanium, the decay of the anti-symmetric stretch mode of interstitial oxygen involves the symmetric stretch mode with a strong isotope dependence. For example, it was shown that for a natural silicon sample, the lifetime of the anti-symmetric vibration is 11.4 ps. When the isotope of one of the silicon atoms is increased to 29Si, the lifetime increases to 19 ps. In similar manner, when the silicon atom is changed to 30Si, the lifetime becomes 27 ps.[17]

text: Two-dimensional IR[edit]

text: Two-dimensional infrared correlation spectroscopy analysis combines multiple samples of infrared spectra to reveal more complex properties. By extending the spectral information of a perturbed sample, spectral analysis is simplified and resolution is enhanced. The 2D synchronous and 2D asynchronous spectra represent a graphical overview of the spectral changes due to a perturbation (such as a changing concentration or changing temperature) as well as the relationship between the spectral changes at two different wavenumbers.

text: Nonlinear two-dimensional infrared spectroscopy[18][19] is the infrared version of correlation spectroscopy. Nonlinear two-dimensional infrared spectroscopy is a technique that has become available with the development of femtosecond infrared laser pulses. In this experiment, first a set of pump pulses is applied to the sample. This is followed by a waiting time during which the system is allowed to relax. The typical waiting time lasts from zero to several picoseconds, and the duration can be controlled with a resolution of tens of femtoseconds. A probe pulse is then applied, resulting in the emission of a signal from the sample. The nonlinear two-dimensional infrared spectrum is a two-dimensional correlation plot of the frequency ω1 that was excited by the initial pump pulses and the frequency ω3 excited by the probe pulse after the waiting time. This allows the observation of coupling between different vibrational modes; because of its extremely fine time resolution, it can be used to monitor molecular dynamics on a picosecond timescale. It is still a largely unexplored technique and is becoming increasingly popular for fundamental research.

text: As with two-dimensional nuclear magnetic resonance (2DNMR) spectroscopy, this technique spreads the spectrum in two dimensions and allows for the observation of cross peaks that contain information on the coupling between different modes. In contrast to 2DNMR, nonlinear two-dimensional infrared spectroscopy also involves the excitation to overtones. These excitations result in excited state absorption peaks located below the diagonal and cross peaks. In 2DNMR, two distinct techniques, COSY and NOESY, are frequently used. The cross peaks in the first are related to the scalar coupling, while in the latter they are related to the spin transfer between different nuclei. In nonlinear two-dimensional infrared spectroscopy, analogs have been drawn to these 2DNMR techniques. Nonlinear two-dimensional infrared spectroscopy with zero waiting time corresponds to COSY, and nonlinear two-dimensional infrared spectroscopy with finite waiting time allowing vibrational population transfer corresponds to NOESY. The COSY variant of nonlinear two-dimensional infrared spectroscopy has been used for determination of the secondary structure content of proteins.[20]