The modern aircrafts are built using various composite materials such as carbon/glass fibre reinforced plastics, GLARE and honeycombs. Manufacturing technologies of composite materials are complicated and include many stages. Small deviations from the technology parameters may cause relatively small defects, but influence of these defects on a total strength of a construction may be essential. ...

Cervical Carotid Imaging With a ContinuousWave Doppler Flowmeter • A noninvasive technique for carotid arteriography using an ultrasonic directional Doppler flowmeter to image the carotid bifurcations is described. The technique uses a position sensing arm to hold the sharply focusing probe and translates the position of arterial flow onto an image storage screen. By multiple manual sweeps acro...

Ultrasonic testing and evaluation procedures typically depend on reference reflectors to establish detection sensitivity and evaluation of test data. Rules and regulations governing safety-related components emphasize on test procedures that assure the detectability of discontinuities at all over the component and oriented in any arbitrary direction. Existing procedures, however, do not provide...

A method is presented based on tomographic reconstruction techniques for the visualization of an ultrasonic field. The tall, narrow piezoelectric elements of a one-dimensional receiving array, rotated about its central axis, provide parallel projection input data for tomographic reconstruction of the field. The technique is demonstrated using simulated ultrasonic beams and experimental measurem...

the aim of this study was to assess the efficacy of apical negative pressure (anp), manual dynamic agitation (mda), passive ultrasonic irrigation (pui) and needle irrigation (ni) as final irrigation activation techniques for smear layer removal in curved root canals.mesiobuccal root canals of 80 freshly extracted maxillary first molars with curvatures ranging between 25° and 35° were used. a gl...

OBJECTIVE The efficiency of rotary, manual and ultrasonic root canal instrumentation techniques was investigated in proximally flattened root canals. MATERIAL AND METHODS Forty human mandibular left and right central incisors, lateral incisors and premolars were used. The pulp tissue was removed and the root canals were filled with red die. Teeth were instrumented using three techniques: (i) ...

Objectives: a) to evaluate the efficacy of various instruments in removal of Ca(OH)2 from the root canals. b) to find out the best instrument or technique out of all five experimental groups. c) to access the inter group comparison among them. Methodology: For this study 70 teeth were selected from an adult population with sufficient crown, complete roots and fully formed apices. Following that...

in biological wastewater treatment large quantities of sludge are produced. this sludge is highly putrescible.for disposal and safe usage should be stabilized. the anaerobic digestion is a standard technique for stabilization. due to the rate imiting step of sludge hydrolysis, anaerobic degradation is a slow process with high digestion time. due to high retention time and sludge dewatering prob...

An ultrasonic inspection method for a graphite ingot was developed to detect internal planar flaws that are oriented in various directions; this method is necessary to perform quality assurance of throat inserts of solid rocket motors. Major problems that are unique to this graphite inspection were solved. An ultrasonic beam in graphite shows uneven propagation behavior both within and among in...

The freezing stage governs several critical parameters of the freeze drying process and the quality of the resulting lyophilized products. This paper presents an integrated ultrasonic transducer (UT) in a stainless steel bottle and its application to real-time diagnostics of the water freezing process. The sensor was directly deposited onto the stainless steel bottle using a sol-gel spray techn...