Energy-dispersive X-ray diffraction (EDXRD) is an analytical technique for characterizing materials. It differs from conventional X-ray diffraction by using polychromatic photons as the source and is usually operated at a fixed angle. With no need for a goniometer, EDXRD is able to collect full diffraction patterns very quickly. EDXRD is …

Crystallography is the branch of science devoted to the study of molecular and crystalline structure and properties. The word crystallography is derived from the Ancient Greek word κρύσταλλος (krústallos; "clear ice, rock-crystal"), and γράφειν (gráphein; "to write"). In July 2012, the United Nations recognised the importance of the science of …

Range imaging is the name for a collection of techniques that are used to produce a 2D image showing the distance to points in a scene from a specific point, normally associated with some type of sensor device. The resulting range image has pixel values that correspond to the distance. …

Diffusion-weighted magnetic resonance imaging (DWI or DW-MRI) is the use of specific MRI sequences as well as software that generates images from the resulting data that uses the diffusion of water molecules to generate contrast in MR images. It allows the mapping of the diffusion process of molecules, mainly water, …

Digital subtraction angiography (DSA) is a fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. Images are produced using contrast medium by subtracting a "pre-contrast image" or mask from subsequent images, once the contrast medium has been introduced into a …

Electron beam computed tomography (EBCT) is a fifth generation computed tomography (CT) scanner in which the X-ray tube is not mechanically spun in order to rotate the source of X-ray photons. This different design was explicitly developed to better image heart structures that never stop moving, performing a complete cycle …

Electron tomography (ET) is a tomography technique for obtaining detailed 3D structures of sub-cellular, macro-molecular, or materials specimens. Electron tomography is an extension of traditional transmission electron microscopy and uses a transmission electron microscope to collect the data. In the process, a beam of electrons is passed through the sample …

Extended X-ray absorption fine structure (EXAFS) is currently the name of a technique used to study the local atomic structure of materials around specific chemical species. Due to its intrinsic short-range sensitivity (less then 1 nm around photoabsorbing atoms) it is regarded to be highly complementary to more standard x-ray …

The field-ion microscope (FIM) was invented by Müller in 1951. It is a type of microscope that can be used to image the arrangement of atoms at the surface of a sharp metal tip. On October 11, 1955, Erwin Müller and his Ph.D. student, Kanwar Bahadur (Pennsylvania State University) observed …

MALDI mass spectrometry imaging (MALDI-MSI) is the use of matrix-assisted laser desorption ionization as a mass spectrometry imaging technique in which the sample, often a thin tissue section, is moved in two dimensions while the mass spectrum is recorded. Advantages, like measuring the distribution of a large amount of analytes …

Electron energy loss spectroscopy (EELS) is a form of electron microscopy in which a material is exposed to a beam of electrons with a known, narrow range of kinetic energies. Some of the electrons will undergo inelastic scattering, which means that they lose energy and have their paths slightly and …

The environmental scanning electron microscope (ESEM) is a scanning electron microscope (SEM) that allows for the option of collecting electron micrographs of specimens that are wet, uncoated, or both by allowing for a gaseous environment in the specimen chamber. Although there were earlier successes at viewing wet specimens in internal …

Fourier transform infrared spectroscopy (FTIR) is a technique used to obtain an infrared spectrum of absorption or emission of a solid, liquid, or gaseous material. An FTIR spectrometer collects high-resolution spectral data over a wide spectral range, from the near- to far-IR region. This confers a significant advantage over a …

Grating-coupled interferometry (GCI) is a biophysical characterization method mainly used in biochemistry and drug discovery for label-free analysis of molecular interactions. Similar to other optical methods such as surface plasmon resonance (SPR) or bio-layer interferometry (BLI), it is based on measuring refractive index changes within an evanescent field near a …

Phase retrieval is the process of algorithmically finding solutions to the phase problem. Given a complex spectrum $${\displaystyle F(k)}$$ , of amplitude $${\displaystyle |F(k)|}$$ , and phase $${\displaystyle \psi (k)}$$ $${\displaystyle F(k)=|F(k)|e^{i\psi (k)}=\int _{-\infty }^{\infty }f(x)\ e^{-2\pi ik\cdot x}\,dx}$$ where x is an M-dimensional spatial coordinate and k is an …