Harry Israel Ringermacher

Towards a Flat-Bottom Hole Standard for Thermal Imaging

Transient thermal imaging has not as yet found a niche among industrial NDE methodologies even though the field has been active since the mid 1980’s. Difficulty with image interpretation is perhaps the primary reason. An ambiguous image leads to false calls and lack of confidence. Ultrasonics, on the other hand appears not to generally suffer from these issues for a simple reason — the term “flat-bottom hole” (FBH) is second nature in the field. Such standards encourage quantitative imaging. The present work provides a deeper insight into certain invariances in 1-D and 2-D heat flow that permit the use of flatbottom hole standards to quantify thermal imaging yielding reproducible and interpretable images of flaws. The very simple theoretical basis for these effects will be described with emphasis placed on the thermal images obtained and the accuracy of the quantitative results. We describe recent work both at GE-CRD and UTRC in the area of thermal standards evaluation.

A new formula describing the scaffold structure of spiral galaxies

We describe a new formula capable of quantitatively characterizing the Hubble sequence of spiral galaxies including grand design and barred spirals. Special shapes such as ring galaxies with inward and outward arms are also described by the analytic continuation of the same formula. The formula is r(φ) =A/log [B tan (φ/2N)]. This function intrinsically generates a bar in a continuous, fixed relationship relative to an arm of arbitrary winding sweep. A is simply a scale parameter while B, together with N, determines the spiral pitch. Roughly, greater N results in tighter winding. Greater B results in greater arm sweep and smaller bar/bulge, while smaller B fits larger bar/bulge with a sharper bar/arm junction. Thus B controls the ‘bar/bulge-to-arm’ size, while N controls the tightness much like the Hubble scheme. The formula can be recast in a form dependent only on a unique point of turnover angle of pitch – essentially a one-parameter fit, aside from a scalefactor. The recast formula is remarkable and unique in that a single parameter can define a spiral shape with either constant or variable pitch capable of tightly fitting Hubble types from grand design spirals to late-type large barred galaxies. We compare the correlation of our pitch parameter to Hubble type with that of the traditional logarithmic spiral for 21 well-shaped galaxies. The pitch parameter of our formula produces a very tight correlation with ideal Hubble type suggesting it is a good discriminator compared to logarithmic pitch, which shows poor correlation here similar to previous works. Representative examples of fitted galaxies are shown.

Flash‐Quenching for High Resolution Thermal Depth Imaging

The Flash lamp “thermal forcing function” is typically an exponentially decaying source. Ideally, one would like to achieve a short rectangular heating pulse simulating a Dirac Delta function. Then heat input is precisely limited so that image analysis can begin, without distortion from incoming heat, immediately following the flash. This allows the earliest temporal resolution of events and thus permits thickness measurements of very thin metal components or thermally thin materials. We will describe a high power handling, compact, electrical approach for lamp quenching that cuts off the lamp exponential tail precisely and present results of its effects on measurement. It can handle up to a 1.2 MW‐average pulse (2400J / 2ms), thus cutting off undesirable tail after 2 ms. These units can be placed in series with every lamp thus optimizing power usage.

The 'how to' of antigravity

Antigravity devices are continuously being proposed without a consistent physical basis. There are, however, models that can be developed, using the General Theory of Relativity, that will allow investigators to examine proposals for antigravity. These models will require both the equations of motion and the field equations from General Relativity. If electromagnetic forces are to be used then the fields must also satisfy Maxwells equations. Several illustrations for modeling antigravity devices are presented, some using a newly proposed extension to General Relativity that is directly applicable to antigravity devices.

Quantitative evaluation of discrete failure events in composites using infrared imaging and acoustic emission

We describe the successful synchronization of thermal imaging with acoustic emission to observe and characterize for the first time the thermal responses of discrete fiber breaks and matrix cracks in composite panels under load in real time. These events can be accurately described by ideal buried point and line thermal sources.

Thermal Imaging at General Electric

We will describe advances in and current applications of thermal imaging at General Electric. Time‐of‐Flight methods are in use at several GE facilities. This approach is sufficiently robust to be used in production. Examples presented include evaluation of metal airfoils and ceramic materials.

Induced matter: Curved N-manifolds encapsulated in Riemann-flat N+1 dimensional space

Liko and Wesson have recently introduced a new five-dimensional induced matter solution of the Einstein equations, a negative curvature Robertson-Walker space embedded in a Riemann-flat five-dimensional manifold. We show that this solution is a special case of a more general theorem prescribing the structure of certain N+1 dimensional Riemann-flat spaces which are all solutions of the Einstein equations. These solutions encapsulate N-dimensional curved manifolds. Such spaces are said to “induce matter” in the submanifolds by virtue of their geometric structure alone. We prove that the N-manifold can be any maximally symmetric space.

Simple Fit of Data Relating Supermassive Black Hole Mass to Galaxy Pitch Angle

Seigar et al. have recently demonstrated a new, tight correlation between galactic central supermassive black hole (BH) mass and the pitch angle of the spiral arm in disk galaxies which they attribute to other indirect correlations. They fit a double power law, governed by five parameters, to the BH mass as a function of pitch. Noting the features of their fitted curve, we show that a simple linear proportion of the BH mass to the cotangent of the pitch angle can obtain the same fit, within error. Such a direct, elegant fit may help shed light on the nature of the correlation.

Lateral heat flow method for thickness independent determination of thermal diffusivity

A pulsed transient thermography method is described where a high-intensity light pulse is used to heat a long, uniform stripe on the surface of a plate. A high spatial resolution, high frame rate focal plane array infrared camera is used to monitor surface temperature. We explain the theoretical model and data analysis framework used to experimentally determine all three thermal diffusivity components from the temperature measurements. The analysis does not require any fitting to the temperature profile and is based on the creation of thermal time-of-flight (tof) images from the temperature data and the relationship between tof and the distance from the stripe edge. The in-plane components of thermal diffusivity are obtained without the need for thickness information. Experimental validation of this procedure was carried out using anisotropic carbon fiber reinforced polymer composites.

Advances in Thermal Time‐of‐Flight Imaging with Flash Quenching

Flash quenching, that is, cutting off the tail of the exponentially decaying light flash, permits great strides in realizing the ideal analysis of high resolution IR data. We will describe some current applications of Quenched Thermal Time‐of‐Flight Imaging to high‐resolution evaluation of metals and fast materials.