Review of progress, QNDE

Methods and devices for emitting volatile materials are disclosed. In some embodiments, methods and devices for emitting two or more fragrance compositions are disclosed. In one non-limiting embodiment of a device, the device has a housing, and the housing is supported on an electrical outlet by a plug at least indirectly joined to the housing. The device contains a first volatile composition and a second volatile composition. The first volatile composition is emitted in an alternating period relative to said second volatile composition. In one embodiment of the method, the volatile compositions are alternately emitted during periods that are greater than 15 minutes and less than 2 hours.

Systems and devices for emitting volatile compositions

Scattering of elastic waves in simple and complex polycrystals

An automatic discharge device (10) includes a housing (20) having a top portion (104) and a base (100) portion, wherein surfaces defining a recess (200) are provided there between for securely holding a container (60). At least one gear (404) is disposed substantially between the recess and a rear panel of the housing. A drive motor (40) is in association with the at least one gear. An actuator arm (30) is also provided. Activation of the drive motor and the at least one gear provides for movement of the actuator arm between at least one of a,pre-actuation position and a discharge position along a path that has a directional component parallel to a longitudinal axis of the recess.

Compact spray device

Ultrasonic backscattering in polycrystals with elongated single phase and duplex microstructures.

In the inspection of titanium material intended for use in aircraft engines, a number of unusual phenomena are observed, including significant fluctuations of the amplitude and phase of back-surface echoes and of the amplitudes of pulse-echo signals from nominally identical flaws[1]. Practical implications include a broadening of the probability of detection curves and difficulties in determining the ultrasonic attenuation, a parameter used in interpreting flaw response data. Incorrect determination of attenuation can lead to errors in distance-gain corrections and hence in estimates of the magnitude of the flaw response. In this paper, we report experiments designed to elucidate the mechanisms responsible for these signal fluctuations.

https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=3243&context=qnde

Ultrasonic Attenuation Measurements in Jet-Engine Titanium Alloys

Developing a quantitative understanding of ultrasonic beam propagation in engineering materials such as Ti-6A1-4V is important because flaw signals can be altered greatly by the macrostructure that the ultrasonic beam propagates through between the transducer and the flaw. Two consequences of the macrostructure are particularly important: 1) back scattered noise which competes with flaw signals and 2) forward scattered signals and the associated beam profile fluctuations which can modulate the strength of flaw signals [1,2,3], These effects are particularly important when ultrasonic beams are used to detect subtle defects such as unvoided, uncracked hard-alpha inclusions (regions with a high content of interstitial nitrogen or oxygen), because the flaw signal is inherently weak due to a small mismatch of acoustic impedance. Each of these effects is controlled by the inherently complex macrostructure which develops during routine processing. Current theories suggest that the most important physical feature which controls noise is the two-point correlation of elastic constants, which is in turn controlled by local variations in crystallographic orientation [4]. Therefore, in order to quantify the effects of the macrostructure on ultrasonic beam propagation, one must determine the elastic constants on a microscopic level with length scales less than the ultrasonic wavelength, approximately 600 μm at 10 MHz.

https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=3603&context=qnde

Use of Electron Backscatter Diffraction in Understanding Texture and the Mechanisms of Backscattered Noise Generation in Titanium Alloys

A system for determining properties of settling suspensions includes a settling container, a mixer, and devices for ultrasonic interrogation transverse to the settling direction. A computer system controls operation of the mixer and the interrogation devices and records the response to the interrogating as a function of settling time, which is then used to determine suspension properties. Attenuation versus settling time for dilute suspensions, such as dilute wood pulp suspension, exhibits a peak at different settling times for suspensions having different properties, and the location of this peak is used as one mechanism for characterizing suspensions. Alternatively or in addition, a plurality of ultrasound receivers are arranged at different angles to a common transmitter to receive scattering responses at a variety of angles during particle settling. Angular differences in scattering as a function of settling time are also used to characterize the suspension.

System and technique for ultrasonic characterization of settling suspensions

During ultrasonic inspection for flaws in engineering materials, it is important to understand the interactions between the inspecting beam and the microstructure in which flaws are embedded. It has been found that in certain materials such interactions can have dramatic effects on the characteristics of the beam as it propagates to and from a flaw and consequently can have deleterious effects on both flaw characterization and the probability of detection. It is well known that, the microstructure can backscatter energy, creating noise which can mask small flaws. In addition, a flaw signal can be attenuated by the removal of energy from the beam by absorption and scattering. Considerable progress has been made towards developing a theoretical understanding of these phenomena. For example, backscattered grain noise has been successfully modeled by Han and Thompson [1] for duplex microstructures that commonly occur in Ti-17 and Ti-6A1-4V alloys used in the rotating components of aircraft engines. In addition, attenuation has been modeled for randomly oriented, equiaxed, cubic microstructures [2], for textured, equiaxed, cubic, stainless-steel [3], and also for elongated textured microstructures [4].

https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=4077&context=qnde

Paul D. Panetta

Papers

Scattering of elastic waves in simple and complex polycrystals

Ultrasonic Attenuation Measurements in Jet-Engine Titanium Alloys

Use of Electron Backscatter Diffraction in Understanding Texture and the Mechanisms of Backscattered Noise Generation in Titanium Alloys

System and technique for ultrasonic characterization of settling suspensions

Observation and Interpretation of Microstructurally Induced Fluctuations of Back-Surface Signals and Ultrasonic Attenuation in Titanium Alloys