Emerging technologies for the non-invasive characterization of physical-mechanical properties of tablets

The density, porosity, breaking force, viscoelastic properties, and the presence or absence of any structural defects or irregularities are important physical-mechanical quality attributes of popular solid dosage forms like tablets. The irregularities associated with these attributes may influence the drug product functionality. Thus, an accurate and efficient characterization of these properties is critical for successful development and manufacturing of a robust tablets. These properties are mainly analyzed and monitored with traditional pharmacopeial and non-pharmacopeial methods. Such methods are associated with several challenges such as lack of spatial resolution, efficiency, or sample-sparing attributes. Recent advances in technology, design, instrumentation, and software have led to the emergence of newer techniques for non-invasive characterization of physical-mechanical properties of tablets. These techniques include near infrared spectroscopy, Raman spectroscopy, X-ray microtomography, nuclear magnetic resonance (NMR) imaging, terahertz pulsed imaging, laser-induced breakdown spectroscopy, and various acoustic- and thermal-based techniques. Such state-of-the-art techniques are currently applied at various stages of development and manufacturing of tablets at industrial scale. Each technique has specific advantages or challenges with respect to operational efficiency and cost, compared to traditional analytical methods. Currently, most of these techniques are used as secondary analytical tools to support the traditional methods in characterizing or monitoring tablet quality attributes. Therefore, further development in the instrumentation and software, and studies on the applications are necessary for their adoption in routine analysis and monitoring of tablet physical-mechanical properties

Current state of methods and means of ultrasonic control rental with use of electromagnetic-acoustic converters

Выполнен анализ информационных источников по теоретическому и модельному исследованиям, разработкам способов и приборов для электромагнитно-акустического контроля металлоизделий, а также применению таких устройств для дефектоскопии, толщинометрии, диагностики и определения физико – механических характеристик материалов металлоизделий. Установлено, что на сегодня не разработаны общие теоретические основы построения электромагнитно-акустических преобразователей различного назначения. Поэтому работы в этом направлении актуальны. Показана перспективность использования импульсного намагничивания изделий, что позволяет увеличивать индукцию магнитного поля до 2…3 Тл. Однако необходимо решать вопрос подавления шумов Баркгаузена. Кроме того, при контроле ферромагнитных изделий типа труб, заготовок, рельсов, листов и др. необходимо решать вопрос сильного притяжения преобразователя к металлу, а при использовании постоянных магнитов – налипания отслоившейся окалины. Экспериментально показана высокая эффективность применения устройств и установок для дефектоскопии, особенно при автоматическом контроле больших объемов катаных изделий.The analysis of information sources on theoretical and model research, the development of methods and devices for electromagnetic - acoustic control of metal products, as well as the use of such devices for flaw detection, thickness measurement, diagnostics and determination of physico - mechanical characteristics of metal products is carried out. It is established that today the general theoretical foundations of constructing electromagnetic - acoustic transducers for various purposes have not been developed. Therefore, work in this direction is relevant. The prospects of using pulsed magnetization of products is shown, which allows to increase the magnetic field induction to 2 ... 3 T. However, it is necessary to resolve the issue of Barkhausen noise reduction. In addition, when monitoring ferromagnetic products such as pipes, billets, rails, sheets, etc., it is necessary to solve the issue of strong attraction of the converter to the metal, and when using permanent magnets, the adhesion of exfoliated scale. The high efficiency of the use of devices and installations for flaw detection has been experimentally shown, especially with automatic control of large volumes of rolled products

A noncontact ultrasonic platform for structural inspection

Miniature robotic vehicles are receiving increasing attention for use in nondestructive testing (NDE) due to their attractiveness in terms of cost, safety, and their accessibility to areas where manual inspection is not practical. Conventional ultrasonic inspection requires the provision of a suitable coupling liquid between the probe and the structure under test. This necessitates either an on board reservoir or umbilical providing a constant flow of coupling fluid, neither of which are practical for a fleet of miniature robotic inspection vehicles. Air-coupled ultrasound offers the possibility of couplant-free ultrasonic inspection. This paper describes the sensing methodology, hardware platform and algorithms used to integrate an air-coupled ultrasonic inspection payload into a miniature robotic vehicle platform. The work takes account of the robot's inherent positional uncertainty when constructing an image of the test specimen from aggregated sensor measurements. This paper concludes with the results of an automatic inspection of a aluminium sample

Current state of methods and means of ultrasonic control rental with use of electromagnetic-acoustic converters

Выполнен анализ информационных источников по теоретическому и модельному исследованиям, разработкам способов и приборов для электромагнитно-акустического контроля металлоизделий, а также применению таких устройств для дефектоскопии, толщинометрии, диагностики и определения физико – механических характеристик материалов металлоизделий. Установлено, что на сегодня не разработаны общие теоретические основы построения электромагнитно-акустических преобразователей различного назначения. Поэтому работы в этом направлении актуальны. Показана перспективность использования импульсного намагничивания изделий, что позволяет увеличивать индукцию магнитного поля до 2…3 Тл. Однако необходимо решать вопрос подавления шумов Баркгаузена. Кроме того, при контроле ферромагнитных изделий типа труб, заготовок, рельсов, листов и др. необходимо решать вопрос сильного притяжения преобразователя к металлу, а при использовании постоянных магнитов – налипания отслоившейся окалины. Экспериментально показана высокая эффективность применения устройств и установок для дефектоскопии, особенно при автоматическом контроле больших объемов катаных изделий.The analysis of information sources on theoretical and model research, the development of methods and devices for electromagnetic - acoustic control of metal products, as well as the use of such devices for flaw detection, thickness measurement, diagnostics and determination of physico - mechanical characteristics of metal products is carried out. It is established that today the general theoretical foundations of constructing electromagnetic - acoustic transducers for various purposes have not been developed. Therefore, work in this direction is relevant. The prospects of using pulsed magnetization of products is shown, which allows to increase the magnetic field induction to 2 ... 3 T. However, it is necessary to resolve the issue of Barkhausen noise reduction. In addition, when monitoring ferromagnetic products such as pipes, billets, rails, sheets, etc., it is necessary to solve the issue of strong attraction of the converter to the metal, and when using permanent magnets, the adhesion of exfoliated scale. The high efficiency of the use of devices and installations for flaw detection has been experimentally shown, especially with automatic control of large volumes of rolled products

Magnetic phase transitions in Gd64Sc36 studied using non-contact ultrasonics

The speed and attenuation of ultrasound propagation can be used to determine material properties and identify phase transitions. Standard ultrasonic contact techniques are not always convenient due to the necessity of using couplant; however, recently reliable non-contact ultrasonic techniques involving electromagnetic generation and detection of ultrasound with electromagnetic acoustic transducers (EMATs) have been developed for use on electrically conducting and/or magnetic materials. We present a detailed study of magnetic phase transitions in a single crystal sample of Gd64Sc36 magnetic alloy using contact and non-contact ultrasonic techniques for two orientations of external magnetic field. Phase diagrams are constructed based on measurements of elastic constant C33, the attenuation and the efficiency of generation when using an EMAT. The EMATs are shown to provide additional information related to the magnetic phase transitions in the studied sample, and results identify a conical helix phase in Gd64Sc36 in the magnetic field orientation

Analytical ultrasonics for evaluation of composite materials response. Part 2: Generation and detection

To evaluate the response of composite materials, it is imperative that the input excitation as well as the observed output be well characterized. This characterization ideally should be in terms of displacements as a function of time with high spatial resolution. Additionally, the ability to prescribe these features for the excitation is highly desirable. Various methods for generating and detecting ultrasound in advanced composite materials are examined. Characterization and tailoring of input excitation is considered for contact and noncontact, mechanical, and electromechanical devices. Type of response as well as temporal and spatial resolution of detection methods are discussed as well. Results of investigations at Virginia Tech in application of these techniques to characterizing the response of advanced composites are presented

Effective Focal Area Dimension Optimization of Shear Horizontal Point-Focusing EMAT Using Orthogonal Test Method

To overcome the shortcomings of low energy conversion efficiency of electromagnetic acoustic transducers (EMATs), point-focusing shear horizontal (PFSH) wave EMAT is used to focus the wave energy into a specific area. Many factors will affect the capability of the focusing transducer, and in addition to considering the signal intensity, the detection accuracy is also required to be investigated. Specifically, to simplify the test process, we use the orthogonal test method to study the effect of different influence parameters on signal intensity and focal area dimensions. Seven factors are selected, and three results are determined in the test. Range analysis shows that for signal amplitude M , the top three impact factors are the coil width w , coil turns n , and focal length lF (equal to bandwidth factor α ). Moreover, magnet number m and frequency fc dominate the effective focal length lfd , and aperture angle θ determines the effective focal width wfd . To enable higher signal intensity and smaller focal area dimensions, it is necessary to consider various factors on the PFSH-EMAT focusing performance. The test’s signal intensity with optimized parameters’ combination at the focal point is nearly 144.42% higher than the average of all the tests, lfd decreased by 37.84%, and wfd decreased by 50.59%. The experiment also verified that focusing EMAT with optimized parameters has a better focusing performance

Orthogonal Optimal Design Method for Point-Focusing EMAT Considering Focal Area Dimensions

Although ultrasonic focusing methods have been widely used in electromagnetic acoustic transducers (EMATs) to solve the problem of their low energy conversion efficiency, the influence of focusing accuracy on defect identification also warrants consideration. The dimension of the focal area that acts as an important factor and affects the detection accuracy has not been fully investigated recently to our knowledge. In this work, we report a parameter optimization method using an orthogonal test when considering the focusing intensity and focal area together. The results of the range analysis show that the factor lift-off distance hl has the greatest impact on signal intensity M. Considering the dimensions of the focal area, bandwidth factor α has the largest effect on the effective focal length Lfd. For effective focal width Wfd, the concentric line source (CLS) number n has the largest effect. Therefore, a smaller lift-off distance, larger CLS number, and suitable bandwidth factor α are required in a point-focusing SV EMAT (PFSV-EMAT). The optimal combination of parameters can be obtained by considering the influence of different factors on the results. The experiment shows that the signal intensity of the optimized transducer is nearly 400% higher than non-optimized ones and the effective focal length and width are reduced by 15% and 57%, respectively

Coupled Finite Element Modelling and Transduction Analysis of a Novel EMAT Configuration Operating on Pipe Steel Materials

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonElectromagnetic Acoustic Transducers (EMATs) are advanced ultrasonic transducers that generate and detect acoustic waves in an electrically conducting material without making physical contact with the material unlike its counterpart, the piezoelectric transducers (PZT). The conventional EMAT consists of copper coil that generates the dynamic field when excited with a sinusoidal current, a permanent or electromagnet that provides the bias field and the conducting material specimen. The complex interaction between the bias field and the Eddy current induced within the skin depth of the conducting material by the dynamic field gives rise to the acoustic wave that then propagates within the surface of the material. Within the research a finite element EMAT model was developed using commercial software Comsol Multiphysics, to study and compare the Eddy current density and Lorentz force density generated by three EMAT configurations: The Meander-line, Spiral and Key Type EMAT configuration respectively. It was observed that apart from the ease of fabrication and simplicity of connectivity when stacked in layers, the Key Type coil EMAT showed a high tendency to generate higher amplitude of Eddy current and Lorentz force test materials especially when stacked in layers. Also, the effect of varying some key EMAT parameters was investigated to determine the optimal performance of Key Type EMAT configuration on CS70 pipe steel plate. The research further developed a coupled finite element model using the same software, Comsol Multiphysics to account for the generation, propagation and detection of acoustic wave by the Key Type EMAT configuration on CS70 grade of pipe steel. The model can solve the magnetostatic, electrodynamic and elastic equations that give rise to acoustic wave generation, propagation and detection on the test material. The developed coupled finite element model was validated both analytically and experimentally to establish the validity of the finite element model. The analytical and experimental results obtained were consistent with the numerical result with an average discrepancy less than 9 % percent. Finally, the research developed a novel modelling strategy to decouple and quantify the various transduction forces in operation when normally-biased EMAT and magnetostrictive EMAT configurations are used on various grades of pipe steel materials. The strategy established the value of the critical excitation current beyond which acoustic wave is generated solely by the dynamic Lorentz force mechanism. The critical excitation currents when Magnetostrictive EMAT configurations are used to generate acoustic wave was found to be; 268A, 274A, 279A, 290A and 305A for CS70, L80SS, L80A, TN80Cr3 and J55 respectively. While for Normally-Biased EMAT configurations, the critical excitation current was found to be 190A, 205A, 240A, 160A and 200A respectively. This work also compared the critical excitation current of the two EMAT configurations studied and established that normally-biased EMATs are more efficient in the generation of acoustic waves than their magnetostrictive counterpart due to their lower value of critical excitation current.Petroleum Technology Development Fund (PTDF) Nigeri