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This chapter aims at the application of industrial process tomography (IPT) in the monitoring and measurement of mineral transportation, especially slurry flows. Flow pattern identification with IPTs is introduced based on the brief description of the characteristics of typical flow patterns in slurry flow and oil–gas–water multiphase flow. Measurement methods of flow parameters of multiphase flow are discussed based on IPTs of different sensing principles. IPTs in multisensor fusion are introduced as a trend of future development.

Computerized tomography (CT) is the process of recovering a distribution of some parameter from physically obtained approximations of its line integrals along lines of known locations. CT devices used in brain imaging include x-ray CT that aims at recovering the distribution of x-ray attenuation coefficients and positron emission tomography and single-photon emission computerized tomography, which aim at recovering the distribution of radioactivity that results in the emission of positrons and single photons, respectively. The production of the desired distribution from data collected by such a device is done on a computer by a reconstruction method. Such methods are the subject matter of this article.

Electrical tomography technology is a kind of process tomography technology. It is accompanied by the development of computer technology and sensor technology. Electrical resistance tomography is a kind of mode of electrical tomography. It has some excellent characteristics that are non-invasive, portable, l ow cost and fast response etc. In this paper, the system of ERT unit are introduced. Mainly summarized the application of ERT system in the measurement of multiphase flow, medicine, the concrete structure detection and other aspects.

The paper presents a novel dual modality reconstruction algorithm (DMR) based on processing data collected from γ-ray and electrical capacitance tomography systems. The tomograms are shown for noise-free data as well as for data captured for a gas/solids flow in a vertical channel.

This paper deals with tomographic techniques for two-dimensional spatially resolved concentration measurements indoors. This represents a significant advance over the traditional point measuring me ...

In electrical impedance tomography (EIT) currents are applied through an array of electrodes attached on the surface of the object and the resulting voltages are measured using the same electrodes. Based on these voltage measurements an estimate for the internal admittivity distribution is computed. The reconstruction is usually made in a fixed pixel grid. However, if it is known that the object consists of a few separate subregions of different materials with constant admittivity values one can employ shape estimation methods. In this study, we propose a novel shape estimation method for the recovery of a free-surface which is an open interface between two regions of unknown admittivities. The motivation for the method stems from the industrial process tomography applications of EIT. We are especially interested in the estimation of free-surface between air and conductive liquid in industrial process pipelines, and in addition, in the estimation of free-surface between oil and water. The proposed method is tested with computer simulations. From the simulations a promising performance of the approach can be seen. Copyright © 2005 John Wiley & Sons, Ltd.

Computed tomography has revolutionized diagnostic radiology with the introduction of spiral CT in the early 1990s, allowing for the first time the acquisition of volume data without the danger of misregistration or double registration of anatomical details. The next revolution occurred in 1998 when all major CT manufacturers introduced multislice CT (MSCT) systems, which typically offered simultaneous acquisition of four slices, providing considerable improvement towards the goal of isotropic three-dimensional imaging. The most recent generation of MSCT systems acquire 64 slices per rotation, enabling a whole body CTA with 1,500 mm scan range and an isotropic resolution of down to 0.4 mm in only 22- 25 s. The tube and the detector measurement system belong to the most important system components of a CT system, having a large influence on system performance. For example, new rotating envelope tube design principles allow for faster rotation times and for double z-sampling techniques in order to increase resolution. The applied dose is ultimately the limiting factor for the improvement of image quality and increase in isotropic resolution. In order to make best diagnostic use of the applied dose, sophisticated dynamic dose adaptation techniques to patient size and geometry have been developed.

This paper reviews the foundation of gamma-ray transmission tomography methods in industry. There are two categories of industrial tomography systems; those using a single source and automatic scanning, and those using multiple sources and no mechanical scanning. The main purpose of the latter is to reveal the dynamics of industrial processes. Compared to medical tomography temporal resolution is more important for these systems than spatial resolution. Such systems have also been realised using electronic scanning of multiple X-ray sources. Examples on different systems are given. Future developments include dual energy and multiple modality configurations enabling component fraction measurements on multiphase systems. Tomographic methods are also being implemented in permanently installed gauges with a limited number of projections, a priori information and parametric description of the process rather than reconstructed images.

Summary Computed tomography utilises a rotating X-ray source combined with multiple detectors in the latest scanners. This data can then be processed in numerous ways to provide axial, multi-planar and 3D images for diagnostic purposes. This modality has rapidly developed since its inception in direct relationship to the exponential increase in computer technology with a corresponding increase in its range of applications.

In chemical industries, process diagnostics have traditionally been achieved using discrete sensors installed in the critical plant locations and linked into a plant control system. The usefulness of such an approach is limited, as important information about the processes is lost. This paper demonstrates a different way of looking into the spatial and temporal characteristics of the industrial processes by employing techniques of industrial process tomography. The principles behind tomographic measurements are outlined and examples illustrating the capabilities of this approach are presented. These include imaging of the processes confined within process vessels such as fluidization and nylon polymerization, as well as an example of a transport-dominated process – flow in a pneumatic conveyor. The advantages, limitations and potential future uses of process tomography are discussed.

As a generic 'tool' electrical impedance tomography (EIT) is useful in improving the modelling and design of many complex processes and for process control (Williams R A and Beck M S 1995 Process Tomography: Principles, Techniques and Applications (Woburn, MA: Butterworth Heinemann) pp 11?25, Neuffer D, Alvarez A, Owens D H, Ostrowski K L, Luke S P and Williams R A 1999 Proc. 1st World Congr. on Industrial Process Tomography (Buxton, UK) pp 71?7). However, existing developments of the EIT technique are only applicable to aqueous-based fluids that possess continuous admittance property (Xie C G, Reinecke N, Beck M S, Mewes D and Williams R A 1994 Process Tomography?A Strategy for Industrial Exploitation ed M S Beck pp 25?32). For example, it would not be suitable for a stratified flow or an intermittent flow in a horizontal channel or large bubble formation and foams since some of the electrodes may lose contact with the conductive fluid. The paper reports a preliminary study of a novel sensor and apparatus, which seeks to address some significant shortcomings in EIT application through use of a new sensing strategy and apparatus for measuring complex multiphase flows, such as oil/gas/water flow or bubble formation and foams. The major feature of the sensing system is to employ a single conductive ring as a tomographic sensor instead of a number of electrodes as in conventional EIT. The strategy facilitates a more homogeneous sensitivity distribution throughout the sensing domain of the conductive ring, which is less affected by the contact area or geometry of electrodes than in previous EIT systems. The sensor can be conveniently constructed as a flange-based flow sensor, if required, without the need to drill holes in the pipe wall. Therefore, it provides a realistic way to measure the dynamic changes of flowing fluids. The novel methodology is believed to offer a significant advance in enabling a more flexible and robust EIT system to be devised for on-line measurement and control of flow in oil, pharmaceuticals and food industries.

Dual-modality imaging is a technique in which computed tomography (CT) or magnetic resonance imaging is combined with positron emission tomography or single-photon emission CT to acquire structural and functional images with an integated system. The data are acquired in a single procedure; the patient remains on the scanner table while undergoing both x-ray and radionuclide studies to facilitate correlation between the structural and functional images. The resulting data can aid in localization, enabling more specific diagnosis than can be obtained with a conventional imaging study. In addition, the anatomic information can be used to compensate the correlated radionuclide data for physical perturbations such as photon attenuation, scatter radiation, and partial volume errors. Thus, dual-modality imaging provides a priori information that can improve both the visual quality and the quantitative accuracy of the radionuclide images. Dual-modality imaging systems are also being developed for biologic research involving small animals. Small-animal dual-modality systems offer advantages for measurements that currently are performed invasively with autoradiography and tissue sampling. By acquiring data noninvasively, dual-modality imaging permits serial studies in a single animal, enables measurements to be performed with fewer animals, and improves the statistical quality of the data.

Methods of optical tomography of biological tissues are considered, which include pulse-modulation and frequency-modulation tomography, diffusion tomography with the use of cw radiation sources, optical coherent tomography, speckle-correlation tomography of nonstationary media, and optoacoustic tomography. The method for controlling the optical properties of tissues is studied from the point of view of increasing a probing depth in optical coherent tomography. The modern state and prospects of the development of optical tomography are discussed.

Industrial Computed Tomographic (ICT) imaging systems based on X-rays require a high stability source. This emanates from the fact that in a computed tomographic imaging system, statistical variation inherent in the penetrating radiation used to probe the specimen, electronic noise generated in the detection system and reconstruction errors play an important role in the overall quality of the image. A conventional industrial X-ray machine used for routine radiography work is not suitable for tomographic imaging applications because of its output dose variations. In this paper, an experiment is described to utilise a general-purpose 160 kV constant potential industrial X-ray machine with significant ripple in its output beam, in an experimental Computed Industrial Tomographic Imaging System (CITIS) developed at Isotope Applications Division of Bhabha Atomic Research Centre. Studies carried out include the analysis of temporal profile of X-ray beam intensity and online averaging of detected signals for the minimization of periodic ripple, which mainly showed up, at the power line frequency. A tomographic image of a typical specimen, reconstructed with the processed projection data is analysed. It was observed that the mean value of reconstructed linear absorption coefficients and standard deviation computed over a window within a constant density region of the object were stable

Electromagnetic flow meters have succesfully been used in many industries to measure the mean flow velocity of conductive liquids. This technology works reliably in single phase flows with axisymmetric flow profiles but can be inaccurate with asymmetric flows, which are encountered, for example, in multiphase flows, pipe elbows and T-junctions. Some computational techniques and measurement devices with multiple excitation coils and measurement electrodes have recently been proposed to be used in cases of asymmetric flows. In earlier studies, we proposed a computational approach for electromagnetic flow tomography (EMFT) for estimating velocity fields utilizing several excitation coils and a set of measurement electrodes attached to the surface of the pipe. This approach has been shown to work well with simulated data but has not been tested extensively with real measurements. In this paper, an EMFT system with four excitation coils and 16 measurement electrodes is introduced. The system is capable of using both square wave and sinusoidal coil current excitations and all the coils can be excited individually, also enabling parallel excitations with multiple frequencies. The studies undertaken in the paper demonstrate that the proposed EMFT system, together with the earlier introduced velocity field reconstruction approach, is capable of producing reliable velocify field estimates in a laboratory environment with both axisymmetric and asymmetric single phase flows.

International audience; Magnetic resonance electric properties tomography is a non-destructive imaging modality that maps the spatial distribution of the electrical conductivity and permittivity of the human body using standard clinical magnetic resonance imaging systems. From the B+1 magnetic field maps and the local form of the Maxwell equations, several schemes have been derived to provide direct approximated formulas but they suffer from instabilities. In this paper, we propose to address it as an inverse problem solved by a constrained optimization algorithm where we exploit the weak formulation of the electric Helmholtz equation and a Lagrangian approach. We derive the associated adjoint field equation and employ a quasi-Newton minimization scheme. We also take advantage of a regularisation strategy based on geometrical a priori information for defining large zones into which the electric parameters are known to be piece-wise constant.

Hyperthermia has proven to be beneficial to treating superficial malignancies, particularly chest wall recurrences of breast cancer. During hyperthermia, monitoring the time–temperature profiles in the target and surrounding areas is of great significance for the effect of therapy. An ultrasound-based temperature imaging method has advantages over other approaches. When the temperature around the tumor is calculated by using the propagation speed of ultrasound, there always exist overshoot artifacts along the boundary between different tissues. In this paper, we present a new method combined with empirical mode decomposition (EDM), similarity constraint, and continuity constraint to optimize the temperature images. Simulation and phantom experiment results compared with those from our previously proposed method prove that the EMD-based method can build a better temperature field image, which can adaptively yield better temperature images with less computation for assistant medical treatment control.

The objective of this study is to develop and test a unique X-ray-induced acoustic computed tomography system that combines the advantages of high X-ray imaging contrast and high ultrasonic spatial resolution. The system features a 5 MHz 128-element ultrasound transducer ring-array formed into a full circular aperture. A parallel data receiver, which consists of a dedicated 128-channel preamplifier and a 128-channel data acquisition module, provides full tomographic imaging at a speed of up to 25 frames per second. Details of the system design and calibration are presented, along with the characteristic results of the imaging resolution. The tomographic imaging performance is demonstrated through images of a phantom with a spatial resolution up to 138 μm. The study results indicate that this imaging device and the methodology provide a rapid and high resolution approach for the dynamic imaging of information, and it may have the potential for becoming a promising noninvasive imaging modality to be used in...

The inspection system is crucial to ensure the system is always in a good condition. A technique that can be used for inspection system is process tomography. By promising non-destructive approach; various types of process tomography applied in civil, manufacturing and electrical applications. The purpose of this paper is to review the types of process tomography such as ultrasonic tomography, x-ray tomography, optical tomography, electrical resistance tomography, and electrical impedance tomography that had been applied to the inspection system. Variety techniques of inspection based on those sensors briefly discussed in this paper. The result showed that the process tomography expanded tremendously in the inspection system. Finally, a potential future research on the inspection system in the civil application proposed in this paper.

The advantage of using a tomography system is that it provides visualization of component distributions inside a pipe or a process vessel. Tomography is widely used in the medical field. Due to its non-intrusive nature, tomography has caught the interest of various researchers in process applications. There is an extensive research using ultrasonic tomography for various applications. This paper is a review which expounds the principles of ultrasonic tomography systems, the hardware, and the software used in such systems.

In a first pilot study with 3D Ultrasound Computer Tomography especially the speed of sound images of the breast showed promising results for breast cancer detection. Yet, the resolution of transmission tomography in our system is limited in comparison to the reflectivity volumes. In this paper we describe a setup for an improved device overcoming this limitation. An optimized geometry of the transducers in a sparse distribution improves both the contrast in reflection and contrast and resolution in transmission tomography by nearly an order of magnitude. Furthermore data acquisition is accelerated from 10 to less than 2 minutes. The derived methods, simulation, and measuring results are described.

Terahertz (THz) tomography is a recent imaging technique allowing 3D inspection of opaque objects. In this paper, we investigate a dual-energy experimental setup and a THz tomographic reconstruction algorithm based on dual-energy measurements. We discuss how this dualenergy approach is able to extract physical properties of acquired samples in addition to the 3D reconstruction from acquisitions measured with a 84/287GHz transmission scanner.

The measurement of volume fractions and their spatial distribution in multiphase flows is of great interest in many industrial applications. Ultrasound methods are well-suited for the differentiation between liquid and gaseous phases. In a system for ultrasound process tomography, the signal transmission characteristics strongly vary with the composition and the spatial distribution of the phases in the multiphase flow. In this contribution, a simulation technique for ultrasound process tomography of gas / liquid flows is presented, which uses ray-tracing for the simulation of ultrasound wave propagation. The received signals obtained after transmission through the liquid phase and scattering at the interfaces between the liquid and the gaseous inhomogenities are efficiently calculated in the frequency domain. The simulation concept and some results of simulated exemplary scenarios are discussed.

This paper presents a reconstruction method for a conveyor belt X-ray scanning geometry, consisting of a static X-ray source/detector system and an object in uniform motion. Applying conventional reconstruction methods to data acquired in this geometry leads to severe artefacts. We show that by incorporating prior knowledge of the material as well as domain specific knowledge, such artefacts can be largely reduced. This is done by combining concepts of discrete tomography with the expected object domain.

Tomography is a method that has been used for image reconstruction in the medical and engineering fields. Optical tomography is one of the various methods applied in tomography systems. This tomography method is widely used in the medical and processing industries fields because of its special characteristics, such as immunity to electrical noise and interference, high resolution and its hard field sensors. The basic principle of the optical tomography system in measuring an object is based on its wave and radiation source. This article is a review of the characteristics of light and its interaction with matter, the types of optical tomography system, the basic construction of an optical tomography system, types of optoelectronic sensors and image reconstruction.

Electrical capacitance tomography (ECT) is an imaging technique commonly used for imaging dielectric permittivity of insulating objects. In applications such industrial process tomography and non-destructive testing (NDT), the objects under test may exhibit variations in both dielectric permittivity and electrical conductivity. In particular, a sample that includes high conductivity, such as metal, can cause a large change in electrical field in ECT. The metal sample in imaging area will cause a large change in the sensitivity map of ECT compared to free space, which will make the ECT image reconstruction inaccurate. This effect is more severe in grounded conductor than floating conductors, so this paper focuses on grounded conductor. In order to update the sensitivity map, one needs to gain information about the conductivity distribution in ECT problem. Magnetic induction tomography (MIT) is sensitive to electrical conductivity and not sensitive to permittivity variations; therefore, it can be used to visualize the conductivity distribution of the target under test. In this paper, a dual-modality MIT and ECT system is proposed to image a medium including conductors and dielectrics. Both simulated and experimental results are presented, which demonstrate the feasibility of the proposed method.

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In this chapter, we briefly recall the theory of non-commutative tomography in a pedagogical way. We then consider its applications to signal analysis. The advantages and drawbacks of these techniques to finite samples of data are discussed. Then the method is applied, first to signals originating from reflectometry measurements in magnetized fusion plasmas, and then to data obtained from the advection of tracers in a two-dimensional time-dependent flow generated by three point vortices. In the first case, we show that the tomogram allows to pick a base to represent our signal which has the advantage of isolating the reflection coming from the plasma and then to improve the estimation of the density profile. In the second case, we show how, with a "tricky transformation" the method allows us to detect Lévy flights and extract some of their properties.

Transient three-dimensional multiphase flows are a characteristic feature of many industrial processes. The experimental observations and measurements of such flows are extremely difficult, and industrial process tomography has been developed over the last decade into a reliable method for investigating these complex phenomena. Gas-solids flows, such as those in pneumatic conveying systems, exhibit many interesting features and these can be successfully investigated by using electrical capacitance tomography. This paper discusses the current state of the art in this field, advantages and limitations of the technique and required future developments. Various levels of visualization and processing of tomographic data obtained in a pilot-plant-scale pneumatic conveying system are presented. A case study outlining the principles of measuring the mass flow rate of solids in a vertical channel is shown.

Gas/solids flow measurement presents many challenges to academics and engineers. Although this subject has been investigated for many years, it still remains a notorious task. The main difficulty is that all existing multi-phase flow meters are flow-regime-dependent and suffer from severe non-linearity problems. Industrial process tomography is based on measuring a subject, such as a gas/solids flow, from many different viewing angles and reconstructing cross-sectional distributions, i.e. tomographic images. From the images the flow regime can be identified, the solids fraction and velocity profiles be derived, and the volumetric flow rate be measured. This paper discusses these possibilities, in particular with electrical capacitance tomography (ECT). Some new results are presented.

Pixel-based tomography has been used with great success for medical applications where it is most appropriate but this approach does not always transfer easily to industrial applications. For example pixel-based image reconstruction from electrical impedance tomography measurements is well known to be an ill- posed problem and with high noise levels such tomograms cannot be reliable. An alternative approach is to use a parametric representation of the tomogram for which reconstruction can be better posed. The primary reason for parametric modelling however is interpretatio n. This paper compares parametric modelling to other methods and then gives an example of the method for an application to a hydrocyclone. Two tomographic modalities are discussed and the results from parametric modelling are validated. This example demonstrates the great power achievable from a parametric modelling approach to tomographic imaging of industrial processes.

In contrast to X-rays, neutrons can penetrate most metals easily. Neutron attenuation is strongly isotope dependent, and a high contrast is possible for many light-weight elements. Especially their high sensitivity for hydrogen makes them a valuable tool for the detection of organic materials like lubricants, plastics or sealants within metal housings. Neutron radiography and tomography complement the application of X-rays for the inspection of complex and critical components like in automotive and aerospace applications. However, the requirements for beam geometry are much higher for tomography than for simple radiography because the sample cannot be close to the detector, as the sample has to be rotated in the beam, usually by 180°. This paper gives an overview on tomography requirements and limitations, applications and future prospects.

Electrodes at the surface of the volume apply electrical potential into the surrounding area and emergent charge is measured at the boundary. The measured data is then used in an electrostatic model to determine the dielectric permittivity properties of the object. Three-dimensional ECT imaging will become an important tool for industrial imaging for process monitoring in the future

From the Department of Radiology, Division of Neuroradiology,a and Division of Musculoskeletal Imaging,b Indiana University School of Medicine. Reprint requests: Karen S. Caldemeyer, MD, Indiana University School of Medicine, University Hospital, Room 0279, 550 N University Blvd, Indianapolis, IN 46202-5253. J Am Acad Dermatol 1999;41:768-71. Copyright © 1999 by the American Academy of Dermatology, Inc. 0190-9622/99/$8.00 + 0 16/1/98499 C omputed tomography (CT) and magnetic resonance imaging (MRI) are the most widely used cross-sectional imaging methods used in medicine. CT was a revolutionary development of the 1970s. The term computed tomography derives from computed (with computer), tomo (to cut), and graph(y) (pictures). CT uses ionizing radiation, or x-rays, coupled with an electronic detector array to record a pattern of densities and create an image of a “slice” or “cut” of tissue. The x-ray beam rotates around the object within the scanner such that multiple x-ray projections pass through the object (Fig 1). The internal structure of the object can then be reconstructed from the multiple projections of that object.1 As x-rays pass through the patient, they are attenuated. The amount of attenuation depends on the type of tissue through which the x-ray beam passes. X-ray imaging contrast is generated as a consequence of differences in attenuation between adjacent tissues. The higher the attenuation of the x-ray beam, the brighter the tissue on CT images, and the lower the attenuation, the darker the tissue on CT images. Therefore bone and calcification that significantly attenuate the x-ray beam are white. Fat, being rich in carbon, is more transparent than water containing oxygen, which attenuates x-rays to a greater degree.1 Therefore fat is blacker than water on CT. Air causes little attenuation of x-rays and is very black (Figs 2 and 3). Regional or focal deviations from the normal CT appearance will be

This paper is concerned with the development of a novel light source which aids the study of the optoelectronic properties of amorphous semiconductors as optical sensors for process tomography. The light source is an integral part of a prototype industrial process tomographic system which is being developed for the detection and imaging of multiphase flows. In this paper, the design, assembly and performance of the light source are discussed in detail. Findings of the research into the suitability of amorphous semiconductors for industrial process tomography will be presented at a later stage in a subsequent paper.

The method enabling one to obtain tomographic images of an electrically conductive or dielectric object by the excitation of the variable magnetic field inside it and by measuring the resulting field around the object is described. The main equations and theoretical estimations are given. It is shown that phasesensitive measurements should be used in magnetic induction tomography. The measuring system providing the data set necessary for the image reconstruction is discussed. Under the conditions of the measurements discussed in this paper, image reconstruction is possible with the use of a simple method of convolution and back-projection along magnetic lines. Computer simulation demonstrates the visualization of the conductivity distribution by the method of magnetic induction tomography with phase measurements.

Electron tomography is a powerful technique for 3D characterization at the nanoscale. Recent developments focus on extracting a wide range of information about a sample in 3D [1]. Of special interest is the combination of electron tomography with spectroscopic techniques EFTEM, EELS and EDS to recover the information present in spectroscopic signals in three dimensions. Analytical electron tomography allows mapping of chemical variations and gradients, approaching the goal of full 3D elemental quantification [2]. Additionally, EELS tomography can be used to extract information about materials properties or chemical bonding [3,4]. In this presentation we will discuss the steps necessary to successfully combine spectroscopy and tomography and show respective applications.

This paper describes an investigation into the use of optical-fibre sensors in a tomographic measurement system, designed to measure the flow of dry solids in gravity-drop and pneumatic conveyors. A simple model of the system is provided and used to predict the response of both individual sensors and the full system. Results are provided which show that the model is acceptable. The system is used to provide tomographic images of solid concentration within a gravity conveyor.

SummaryMinimally invasive procedures are increasingly combined with radiologic imaging to optimise access and treatment techniques. While endoscopy has become a standard technique in the surgical field for diagnosis and therapy, tomographic guidance is new. Combining both modalities, the transparency of computed tomography and of ultrafast electron beam tomography, together with magnetic resonance imaging (MRI), will optimise both guidance and therapy. By using tomographic scanners for precise instrument positioning, the diameter of instruments [mechanical, laser, radiofrequency (RF), endoscopes etc.] can be minimised. Also electronic equipment, for visualisation and therapy should be integrated into a tomographic work-station. Instruments and electronic equipment are sensitive to MRI and ferromagnetic alloys, and electric impulses cause artifacts in imaging. These problems have to be solved for future therapeutic workstations.

A condensed review of recent advances accomplished in the development and the applications of noninvasive tomographic and velocimetric measurement techniques to multiphase flows and systems is presented. In recent years utilization of such noninvasive techniques has become widespread in many engineering disciplines that deal with systems involving two immiscible phases or more. Tomography provides concentration, holdup, or 2D or 3D density distribution of at least one component of the multiphase system, whereas velocimetry provides the dynamic features of the phase of interest such as the flow pattern, the velocity field, the 2D or 3D instantaneous movements, etc. The following review is divided into two parts. The first part summarizes progress and developments in flow imaging techniques using γ-ray and X-ray transmission tomography; X-ray radiography; neutron transmission tomography and radiography; positron emission tomography; X-ray diffraction tomography; nuclear magnetic resonance imaging; electrica...

This paper focuses on the application of 3D X-ray Computed Tomography (CT) to precisely detect and confirm semiconductor internal physical defects without the need to decapsulate the sample. Equipped with advanced technologies and innovations, today's X-ray machine is capable of reconstructing the two-dimension (2D) sliced images to form 3D images and videos in much shorter time. With the introduction of 3D X-ray CT designed for electronics field, failure mechanisms once only visible after destructive analysis can now be revealed in non-destructive way. The technique not only saves cost, it shortens the turnaround time tremendously and allows customer's response and relevant improvement actions to be taken more efficiently.

Electrical capacitance tomography (ECT) is one of process tomography technique which is developed rapidly in recent years. ECT is an imaging technique to obtain the internal permittivity distribution of a vessel or pipe by using capacitance electrodes sensor. This method has been integrated with ultrasonic tomography as multimodality system to perform multiphase flow measurement such as crude oil separation and oil process industry. In the present paper, a novel type of ECT sensor was developed using copper FR4 material. The electrode sensors can be flexibly bend or curve to fit the pipe surface for optimum measurement. Thus, every single sensor strip is designed to be functioned independently. Such system has lower sensing capability in the central of the sensing area which often contributes to poor imaging result. This problem can be overcome by combining the ECT with ultrasonic tomography to form a dual modality tomography system. By implementing the new ECT sensor, multiphase flow measurement image results can be achieved. The reconstructed image results are presented in this paper.

Electrical resistance tomography (ERT) has the advantages of low cost, non-invasion, no radiation and visualization, and it is a hot research topic in the industrial process tomography (PT). The ERT technology applied to the agriculture is a new research field, which can be used in the crop growth status monitoring, new varieties nurturing and fine cultivation of plants. In the paper, the working model of ERT under the condition of soil environment is studied; the sensitive field model is established and simulated by using COMSOL software. The affects brought by different excitation/measurement with different soil conductivity are studied in detail. The research can provide the significant guidance for the further study of backward problem in tuber ERT system.

X-ray computed tomography is a 3D imaging technique for the non-invasive, non-destructive visualisation and measurement of the internal microstructure of materials. Using X-rays, a series of radiographs of a sample are recorded from different angles, and then used to reconstruct the internal 3D microstructure by means of a suitable reconstruction algorithm. The method has a high penetrating power and probing efficiency, and is unlimited by morphological complexity. This chapter describes the technique, its advantages and limitations, the latest technological advances, and reviews of applications in food systems.