Thin-film quantum dot photodiode for monolithic infrared image sensors

Imaging in the infrared wavelength range has been fundamental in scientific, military and surveillance applications. Currently, it is a crucial enabler of new industries such as autonomous mobility (for obstacle detection), augmented reality (for eye tracking) and biometrics. Ubiquitous deployment of infrared cameras (on a scale similar to visible cameras) is however prevented by high manufacturing cost and low resolution related to the need of using image sensors based on flip-chip hybridization. One way to enable monolithic integration is by replacing expensive, small-scale III-V-based detector chips with narrow bandgap thin-films compatible with 8- and 12-inch full-wafer processing. This work describes a CMOS-compatible pixel stack based on lead sulfide quantum dots (PbS QD) with tunable absorption peak. Photodiode with a 150-nm thick absorber in an inverted architecture shows dark current of 10(-6) A/cm(2) at 2 V reverse bias and EQE above 20% at 1440 nm wavelength. Optical modeling for top illumination architecture can improve the contact transparency to 70%. Additional cooling (193 K) can improve the sensitivity to 60 dB. This stack can be integrated on a CMOS ROIC, enabling order-of-magnitude cost reduction for infrared sensors

Draft genome sequence of Xanthomonas fragariae reveals reductive evolution and distinct virulence-related gene content

Background: Xanthomonas fragariae (Xf) is a bacterial strawberry pathogen and an A2 quarantine organism on strawberry planting stock in the EU. It is taxonomically and metabolically distinct within the genus Xanthomonas, and known for its host specificity. As part of a broader pathogenicity study, the genome of a Belgian, virulent Xf strain (LMG 25863) was assembled to draft status and examined for its pathogenicity related gene content. Results: The Xf draft genome (4.2 Mb) was considerably smaller than most known Xanthomonas genomes (similar to 5 Mb). Only half of the genes coding for TonB-dependent transporters and cell-wall degrading enzymes that are typically present in other Xanthomonas genomes, were found in Xf. Other missing genes/regions with a possible impact on its plant-host interaction were: i) the three loci for xylan degradation and metabolism, ii) a locus coding for a beta-ketoadipate phenolics catabolism pathway, iii) xcs, one of two Type II Secretion System coding regions in Xanthomonas, and iv) the genes coding for the glyoxylate shunt pathway. Conversely, the Xf genome revealed a high content of externally derived DNA and several uncommon, possibly virulence-related features: a Type VI Secretion System, a second Type IV Secretion System and a distinct Type III Secretion System effector repertoire comprised of multiple rare effectors and several putative new ones. Conclusions: The draft genome sequence of LMG 25863 confirms the distinct phylogenetic position of Xf within the genus Xanthomonas and reveals a patchwork of both lost and newly acquired genomic features. These features may help explain the specific, mostly endophytic association of Xf with the strawberry plant

Overview of the 84th Annual UCEA Conference: Blurring the Boundaries of the Academy

To meet the challenges of the next century, continuing higher education is recreating itself to assume position of campus-wide leadership. Traditional continuing education units that were simply the university\u27s off-campus course providers are using their organizational flexibility to take on innovative and expanded roles that include for-profit distance learning centers, international educational partnerships, welfare-to-work initiatives, and post-baccalaureate programs for the changing workforce. While maintaining the academy\u27s high standards of scholarship and research, continuing education is also being asked to become a lead voice in conceiving the new academy and in linking the university to the demands of society. These new roles and initiatives are resulting in unprecedented growth and a reconfiguration of the academy\u27s traditional relationships

Directional eddy current probe configuration for in-line detection of out-of-plane wrinkles

Real-time monitoring of carbon fibre composites during Automated Fibre Placement (AFP) manufacturing remains a challenge for non-destructive evaluation (NDE) techniques. An directional eddy-current (EC) probe with asymmetric transmit and differential receive (Tx-dRx) coils is designed, constructed and characterized to evaluate the detectability of out-of-plane wrinkles. Initial studies were conducted to determine suitable excitation frequencies and to analyse the impact of relative orientations of driver and pickup coils on wrinkle detectability. The probe configurations are evaluated experimentally and employ a new finite element modelling approach to better understand the relationship between eddy-current density and defect detection. The findings indicate that a probe configuration with an asymmetric driver coil normal to the material surface and aligned with the fibre directions, and with differential pickup coils 90 degrees to the scanning direction, shows the best capability for out-of-plane wrinkle detection, with SNR >20 for wrinkles over 1.3 mm in amplitude