Black Forest Engineering (United States)

To ensure that the aging pipeline infrastructure in the USA can be safely operated, the mechanical properties of the pipe materials must be verified. It is hypothesized that characterization of the pipeline steels and their microstructures through nondestructive methods will allow for the estimation of the mechanical properties of interest, namely yield strength, tensile strength, toughness, and ductile-to-brittle transition temperature. This work will discuss how material properties, such as microstructure and chemical composition, affect the mechanical properties as well as strategies for measuring the material properties nondestructively using magnetic Barkhausen emission and ultrasonic velocity and attenuation measurements. Preliminary results on a limited sample set will be shown and challenges encountered will be discussed.

Nearly three decades of research on mentoring has offered empirically supported processes in developing a mentoring relationship. Yet the application of mentoring within family businesses has received little exploration. Since much of the current mentoring literature is focused on general workplace mentoring, it is not clear how the multidimensional and interdependent systems within family businesses might complicate the translation of the existing literature to family business populations. This study examines interorganizational family business mentoring relationships to determine whether there are any issues which differentiate it from the existing mentoring research findings.

The performance of Geiger-mode LAser Detection and Ranging (LADAR) cameras is primarily defined by individual pixel attributes, such as dark count rate (DCR), photon detection efficiency (PDE), jitter, and crosstalk. However, for the expanding LADAR imaging applications, other factors, such as image uniformity, component tolerance, manufacturability, reliability, and operational features, have to be considered. Recently we have developed new 32×32 and 32×128 Read-Out Integrated Circuits (ROIC) for LADAR applications. With multiple filter and absorber structures, the 50-μm-pitch arrays demonstrate pixel crosstalk less than 100 ppm level, while maintaining a PDE greater than 40% at 4 V overbias. Besides the improved epitaxial and process uniformity of the APD arrays, the new ROICs implement a Non-uniform Bias (NUB) circuit providing 4-bit bias voltage tunability over a 2.5 V range to individually bias each pixel. All these features greatly increase the performance uniformity of the LADAR camera. Cameras based on these ROICs were integrated with a data acquisition system developed by Boeing DES. The 32×32 version has a range gate of up to 7 μs and can cover a range window of about 1 km with 14-bit and 0.5 ns timing resolution. The 32×128 camera can be operated at a frame rate of up to 20 kHz with 0.3 ns and 14-bit time resolution through a full CameraLink. The performance of the 32×32 LADAR camera has been demonstrated in a series of field tests on various vehicles.

The stressed liquid-crystal (SLC) electro-optic effect promises fast electro-optic response times even for design wavelengths in the infrared (IR). Here we report characteristics of SLC devices appropriate for use as liquid-crystal-onsilicon (LCOS) spatial light modulators (SLMs) in the near ( λ = 1.8-2.5 μm), mid (3-5.5 μm) and far (8-14 μm) IR bands. For these three bands we fabricated SLC devices with 5, 10, and 20 μm thicknesses; at drive voltages of 25, 50, and 125 V respectively these devices gave half-wave modulation with response speeds in the 1.3-1.6 ms range. Visiblelight measurements on a 20-μm-thick SLC device between crossed polarizers gave a contrast ratio of 360:1 which improved to nearly 18,000:1 with a Babinet-Soleil compensator offsetting residual SLC retardance. Widely available high-voltage options in standard CMOS processes offer sufficient drive for near- and mid-IR SLCOS devices; with modest increase of SLC material birefringence Δn and dielectric anisotropy Δε far-IR devices would be feasible, too. Pixel drivers utilizing these options have pitches less than 24 μm, making 1000 ×1000 SLMs feasible.

We report here on analog modulation effects in ferroelectric liquid crystal (FLC) materials and electrical drive schemes that are appropriate to FLC/VLSI spatial light modulations (SLMs). The deformable-helix ferroelectric (DHF) effect paired with fixed-charge drive can give sub- millisecond grey-scale response with VLSI-compatible drive voltages. New DHF materials with long-pitch nematic phases give superior alignment quality and contrast ratio. We present analog FLC driver circuits suitable for VLSI implementation, and show that providing adequate read/write isolation in optically addressed FLC/VLSI SLMs requires special care.