Examples of such chromophores can be seen in chlorophyll ( used by plants for photosynthesis ), hemoglobin, hemocyanin, and colorful minerals such as malachite and amethyst

Sections of molecules which can undergo such detectable electron transitions can be referred to as chromophores since such transitions absorb electromagnetic radiation ( light ), which may be hypothetically perceived as color somewhere in the electromagnetic spectrum.

When iodine is dissolved in polar solvents which are strong donor solvents such as ketones, ethers, pyridine, the formation of charge-transfer complex leads to modification of the energy gap between the two molecular orbitals, thus different wavelengths were absorbed and iodine has different color in solvents with different polarity.

In non-polar solvents such as hexane, no charge-transfer complexes is formed, and the solution appears violet ( λ < sub > max </ sub > = 520-540 nm ) since the energy gap in I < sub > 2 </ sub > in non-polar solvents is essentially the same as that in the gas phase.

Hence, in a biomolecule such as haemoglobin, tuning the laser to near the charge-transfer electronic transition of the iron center results in a spectrum reflecting only the stretching and bending modes associated with the tetrapyrrole-iron group.

* Projection radiography such as X-rays and CT scans

This low dose of radioiodine is typically tolerated by individuals otherwise allergic to iodine ( such as those unable to tolerate contrast mediums containing larger doses of iodine such as used in CT scan, intravenous pyelogram ( IVP ), and similar imaging diagnostic procedures ).

The use of sophisticated techniques such as computer tomography ( CT ) scans has marked the investigation of the Lindow bodies as particularly important.

Once LEMS is diagnosed, investigations such as a CT scan of the chest are usually performed to identify any possible underlying lung tumors.

Physicians and researchers can use additional laboratory assessments, such as bioimpedance, MRI, or CT, to build on the findings of a clinical assessment ( physical evaluation ).

MRI provides good contrast between the different soft tissues of the body, which makes it especially useful in imaging the brain, muscles, the heart, and cancers compared with other medical imaging techniques such as computed tomography ( CT ) or X-rays.

Conventional radiography is useful, both by itself and in conjunction with CT or MRI, for detecting complications of osteopenia ( reduced bone mass ; pre-osteoporosis ), such as fractures ; for differential diagnosis of osteopenia ; or for follow-up examinations in specific clinical settings, such as soft tissue calcifications, secondary hyperparathyroidism, or osteomalacia in renal osteodystrophy.

Among QCT's advantages: it can be performed at axial and peripheral sites, can be calculated from existing CT scans without a separate radiation dose, is sensitive to change over time, can analyze a region of any size or shape, excludes irrelevant tissue such as fat, muscle, and air, and does not require knowledge of the patient's subpopulation in order to create a clinical score ( e. g. the Z-score of all females of a certain age ).

Because PET imaging is most useful in combination with anatomical imaging, such as CT, modern PET scanners are now available with integrated high-end multi-detector-row CT scanners ( so-called " PET / CT ").

As such, PET data suffer from scatter and random events much more dramatically than CT data does.

While some imaging scans such as CT and MRI isolate organic anatomic changes in the body, PET and SPECT are capable of detecting areas of molecular biology detail ( even prior to anatomic change ).

In addition, computed axial tomography ( CT ) scans of a patient's head may reveal the presence of tumors and other abnormalities such as hydrocephalus.

When such types of tumors are encountered, diagnostic modalities such as ultrasound, CT scans, MRI, angiograms, and nuclear medicine scans are employed prior to ( or during ) biopsy and / or surgical exploration / excision in an attempt to avoid such severe complications.

Often, such bony lesions are absent and it is only the MRI or CT that discloses the presence or absence of a compressive lesion.

The technology is relatively inexpensive and portable, especially when compared with other techniques, such as magnetic resonance imaging ( MRI ) and computed tomography ( CT ).

To do this, imaging technology such as CT scans and MRI ’ s are commonly used to create a 3D image of the tumor.

The CT or MRI is also capable of revealing treatable conditions, such as hydrocephalus, porencephaly, arteriovenous malformation, subdural hematomas and hygromas, and a vermian tumor ( which a few studies suggest are present 5 to 22 %).

Although most common in medicine, CT is also used in other fields, such as nondestructive materials testing.

A PACS consists of four major components: The imaging modalities such as X-ray computed tomography ( CT ) and magnetic resonance imaging ( MRI ), a secured network for the transmission of patient information, workstations for interpreting and reviewing images, and archives for the storage and retrieval of images and reports.

No one will deny that such broad developments and transitions are of great intrinsic interest and the study of ideas in literature would be woefully incomplete without frequent reference to them.

He is confronted with the recurrent crises, such as great natural catastrophes and the great transitions of life -- marriage, incurable disease, widowhood, old age, the certainty of death.

124-126 .</ ref > While other philosophers also recognized such transitions in states of matter, Anaximenes was the first to associate the quality pairs hot / dry and cold / wet with the density of a single material and add a quantitative dimension to the Milesian monistic system .< ref > Kirk, G. S., J. E.

Orchestration differs in that it is only adapting music for an orchestra or musical ensemble while arranging " involves adding compositional techniques, such as new thematic material for introductions, transitions, or modulations, and endings ... Arranging is the art of giving an existing melody musical variety " ( ibid ).

The Diamond, in tight formation and usually at lower speeds ( 400 mph ), performs maneuvers such as formation loops, barrel rolls, and transitions from one formation to another.

Theoretical models have also been developed to study the physics of phase transitions, such as the Landau-Ginzburg theory, Critical exponents and the use of mathematical techniques of quantum field theory and the renormalization group.

However, several important phase transitions, such as the Mott insulator-superfluid transition, are known that do not follow the Ginzburg-Landau paradigm.

In most cases of interest in chemical thermodynamics there are internal degrees of freedom and processes, such as chemical reactions and phase transitions, which always create entropy unless they are at equilibrium, or are maintained at a " running equilibrium " through " quasi-static " changes by being coupled to constraining devices, such as pistons or electrodes, to deliver and receive external work.

Researchers have found that transitions, such as from concrete to abstract logical thought, do not occur at the same time in all domains.

At best this kind of transition had previously been dealt with by having the directions of travel of the actor in the two shots correspond on the screen, but in a film such as The Bank Burglar's Fate ( Jack Adolfi, 1914 ), one can see shot transitions in which a cut is made from an actor just leaving the frame, to a shot of him well inside the frame in an adjoining location, which have the positions and directions so well chosen that to the casual eye his movement appears quite continuous, and the real space and time ellipsis between the shots is concealed.

By 1916 there are a number of films in which there are around 15 to 20 true reverse-angle cuts per hundred shot transitions, such as The Deserter ( Scott Sidney ) and Going Straight.

There, it was first clearly shown that mean field theory approaches failed to predict the correct behavior at the critical point ( which was found to fall under a universality class that includes many other systems, such as liquid-gas transitions ), and had to be replaced by renormalization group theory.

Jewish holy days ( chaggim ), celebrate landmark events in Jewish history, such as the Exodus from Egypt and the giving of the Torah, and sometimes mark the change of seasons and transitions in the agricultural cycle.

But transitions are only allowed in between discrete energy levels such as the two shown above.

These changes can be observed and attributed to various phase transitions, such as key liquid crystal transitions.

Other element of cinéma vérité, such as longer takes, sweeping camera transitions, and jump cuts may be included to complete the effect.

For example geochemical signatures from rocks may help to discover when life first arose on Earth, and analyses of carbon isotope ratios may help to identify climate changes and even to explain major transitions such as the Permian – Triassic extinction event .< ref name =" Twitchett "> A relatively recent discipline, molecular phylogenetics, often helps by using comparisons of different modern organisms ' DNA and RNA to re-construct evolutionary " family trees "; it has also been used to estimate the dates of important evolutionary developments, although this approach is controversial because of doubts about the reliability of the " molecular clock ".

It is possible in some media to use multiple photon absorptions between multiple lower-energy transitions to reach the pump level ; such lasers are called up-conversion lasers.

They are also used in the description of critical phenomena and quantum phase transitions, such as in the BCS theory of superconductivity.

Shot reverse shot is a feature of the " classical " Hollywood style of continuity editing, which deemphasizes transitions between shots such that the spectator perceives one continuous action that develops linearly, chronologically, and logically.

Processes involving phase transitions, such as the drying of adhesives or melting of alloys, liquid transport, chemical reactions, and solid-air-gas systems, in general cannot be observed.

But transitions are only allowed in between discrete energy levels such as the two shown above.

Thermodynamics can be applied to a wide variety of topics in science and engineering, such as engines, phase transitions, chemical reactions, transport phenomena, and even black holes.