Types Of Diagnostic Techniques Research Articles

Diagnostic investigations on the Barberini harp

In the frame of the CO.B.RA project, funded by the Lazio Regional Authority, ENEA carried out a series of diagnostic investigations on numerous instruments from the rich collection of the National Museum of Musical Instruments of Rome. This paper presents the results related to the study of the conservation status of one of the rarest and most significant museum’s instruments, the Barberini harp. To study the original wood essence, the decorative apparatus, the integrity of the instrument structure and to assess its conservation status, two types of diagnostic techniques were used: X-ray radiography and observation of micro-samples under scanning electron microscopy (SEM). Both the analysis methods performed enlighten the realisation techniques and materials of the Barberini harp as well as its state of conservation. The data collected from the diagnostic investigations, in particular those on the wood essence, will be useful for the building of modern instruments, having identical structural characteristics to the old ones, which could be played without the conservative problems connected to the handling of an instrument hundreds of years old, obtaining at the same time the same kind of sound.

Fault tolerant system design and SEU injection based testing

The methodology for the design and testing of fault tolerant systems implemented into an FPGA platform with different types of diagnostic techniques is presented in this paper. Basic principles of partial dynamic reconfiguration are described together with their impact on the fault tolerance features of the digital design implemented into the SRAM-based FPGA. The methodology includes detection and localization of a faulty module in the system and its repair and bringing the system back to the state in which it operates correctly. The automatic repair process of a faulty module is implemented by a partial dynamic reconfiguration driven by a generic controller inside the FPGA. The presented methodology was verified on the ML506 development board with Virtex5 FPGA for different types of RTL components. Fault tolerant systems developed by the presented methodology were tested by means of the newly developed SEU simulation framework. The framework is based on the SEU simulation through the JTAG interface and allows us to select the region of the FPGA where the SEU is placed. The simulator does not require any changes in the tested design and is fully independent of the functions in the FPGA. The external SEU generator into FPGA is implemented and its function is verified on an evaluation board ML506 for several types of fault tolerant architectures. The experimental results show the fault coverage and SEU occurrence causing faulty behavior of verified architectures.

Analysis of Early Deaths After Isolated Lung Transplantation

To determine the causes of death in patients dying within 30 days after lung transplantation at the University of Florida, to assess the importance of several diagnostic modalities for determining the causes of their decline, and to construct an algorithm for the evaluation of patients with severe respiratory compromise occurring early after lung transplantation. Retrospective review of medical records and pathology slides from all patients dying within 30 days after lung transplantation, and biopsy specimen diagnoses from all lung allograft recipients at the University of Florida. Nine deaths occurred during the first 30 days after transplantation among 117 patients undergoing 123 isolated lung transplantation operations. Infections accounted for the greatest number of deaths (bacterial pneumonia, four patients; catheter-related bacteremia, one patient). Persistent pneumonia confirmed by biopsy specimen was usually accompanied by histologic manifestations of acute cellular rejection and was associated with poor patient outcome (ie, death or subsequent development of bronchiolitis obliterans syndrome). In two patients, antibody-mediated rejection either was the immediate cause of death (hyperacute rejection, one patient) or preceded a fatal case of pneumonia (accelerated antibody-mediated rejection, one patient). Other causes of death included hypoxic-ischemic encephalopathy secondary to an intraoperative cardiac arrest (one patient), pulmonary venous thrombosis with bacterial colonization of the thrombotic material (one patient), and ischemic reperfusion injury (one patient). In most patients, more than one type of diagnostic technique was needed to ascertain the cause of the catastrophic decline. The causes of early posttransplant death in our patient group included infections, antibody-mediated rejection, hypoxic-ischemic encephalopathy secondary to cardiac arrest, pulmonary venous thrombosis, and ischemic reperfusion injury. Because these processes often demonstrate overlapping clinical and morphologic features requiring multiple diagnostic techniques for resolution, a systematic multimodality approach to diagnosis is advantageous for determining the causes of decline in individual patients and for estimating the incidences of the different causes of early graft and patient loss in the lung transplant population.

Field Testing of Machine Tool Diagnostic Techniques Using Surface Metrology

Surfaces generated by machine tools are finger print of the machine and tool combination. Any change in the condition of either should be reflected in the component produced specially in the nature of component surfaces generated and its dimensions. If the variables involved in the process like cutting tool, workpiece material and cutting conditions are standardized then the variation in the condition of the machine alone would affect the component produced. The changes in the component surfaces and dimensions could then be used to diagnose the condition of the machine tool. This paper summarizes the results of field trials of this type of diagnostic technique applied to CNC milling machine.

Determination of Magnetic Imperfections in Thin Films

By means of a selective ferromagnetic resonance technique, we have succeeded in determining the spatial distribution of the magnetic properties of thin magnetic films. In contrast to other types of diagnostic techniques, the method determines the relevant local magnetic parameters of the sample directly. This is accomplished by sequentially exposing small areas of the film to an rf magnetic field via an aperture in one of the walls of a microwave cavity. To obtain maximum resolution at a given apparatus sensitivity, the aperture wall is substituted by a vacuum-deposited copper film on a dielectric substrate. To data, magnetic quantities such as anisotropy, exchange constant, linewidth, gyromagnetic ratio, magnetization, etc. of regions as small as 5 μ in diameter have been selectively examined. Since spatial variation of these quantities is due to imperfections in the material, results of our measurement exhibit the direct influence of these imperfections on the local magnetic properties of the film. For example, we have found that the effective magnetization decreases and linewidth increases substantially near a nonmagnetic imperfection, and also the existence of regions where the magnetic easy axis rotates gradually over π/2 rad, etc. Typical data on Permalloy films are presented along with a discussion of the theoretical and experimental aspects of the method.