Low noise charge injection in the CCD22

The inclusion of a charge injection structure on a charge coupled device (CCD) allows for the mitigation of charge transfer loss which can be caused by radiation induced charge trapping defects. Any traps present in the pixels of the CCD are filled by the injected charge as it is swept through the device and consequently, the charge transfer efficiency is improved in subsequently acquired images. To date, a number of different types of CCD have been manufactured featuring a variety of charge injection techniques. The e2v Technologies CCD22, used in the EPIC MOS focal plane instruments of XMM-Newton, is one such device and is the subject of this paper. A detailed understanding of charge injection operation and the use of charge injection to mitigate charge transfer losses resulting from radiation damage to CCDs will benefit a number of space projects planned for the future, including the ESA GAIA and X-ray Evolving Universe Spectrometry (XEUS) missions.The charge injection structure and mode of operation of the CCD22 are presented, followed by a detailed analysis of the uniformity and repeatability of the charge injection amplitude across the columns of the device. The effects of proton irradiation on the charge injection characteristics are also presented, in particular the effect of radiation induced bright pixels on the injected charge level

Analysis of Vertebrae Pathologies of Grave A650 Chryssi Island, Crete, Greece

This study of multiple, co-mingled adult individuals located in grave A650 on Chryssi Island, Crete, Greece, examines the prevalence of several pathologies of the vertebrae. This grave was built into a collapsed Late Minoan period house (1400-1100 B.C.E.). Grave A650, which likely dates to the 5th – 7th century C.E., shows evidence of being used over a long period of time and may have served as an ossuary. The pathologies of approximately 30 recovered vertebrae, both complete and incomplete, show signs of degenerative joint disease, spondylolisthesis, and body expansion. Researching this data aims to accomplish a comprehensive understanding of what the present pathologies indicate about the physical activity endured by individuals during their lifetime. Conclusions of this data reveal these co-mingled individuals endured intense and sustained physical activity throughout their lives. There were high numbers of degenerative joint diseases in the thoracic vertebrae, which could indicate repetitive movement in bending down. A plausible cause of this intense labor could be slavery, as revealed by accompanying evidence in the ossuary itself

Is This an OER? : Addressing the Complex Relationship Between Open and Affordable Course Materials

Our poster will examine the work that open educational resource (OER) advocates do to highlight OER and how this work often intersects with other affordable course material initiatives. Specifically, we will highlight the complex intersections between OER and affordable learning and why the differences between these types of course materials matter. In addition to discussing the unique challenges that present themselves when advocating for both OER and affordable course materials, this poster will address: Messaging for instructors and institutional stakeholders about what counts as OER Navigating support for the use of affordable course materials without undercutting the open message The institutional labor connected to these material type

The impact of low energy proton damage on the operational characteristics of EPIC-MOS CCDs

The University of Tübingen 3.5 MeV Van de Graaf accelerator facility was used to investigate the effect of low energy protons on the performance of the European Photon Imaging Camera (EPIC), metal–oxide semiconductor (MOS), charge coupled devices (CCDs). Two CCDs were irradiated in different parts of their detecting areas using different proton spectra and dose rates. Iron-55 was the calibration source in all cases and was used to measure any increases in charge transfer inefficiency (CTI) and spectral resolution of the CCDs. Additional changes in the CCD bright pixel table and changes in the low X-ray energy response of the device were examined. The Monte Carlo code Stopping Range of Ions in Matter (SRIM) was used to model the effect of a 10 MeV equivalent fluence of protons interacting with the CCD. Since the non-ionising energy loss (NIEL) function could not be applied effectively at such low proton energies. From the 10 MeV values, the expected CTI degradation could be calculated and then compared to the measured CTI changes

Isolated hip and ankle fatigue are unlikely risk factors for anterior cruciate ligament injury

Lower extremity neuromuscular fatigue purportedly increases anterior cruciate ligament (ACL) injury risk through promotion of extreme landing mechanics. However, the impact of fatigue on muscle groups critical to the landing strategy remains unclear. This study examined the effects of isolated hip rotator and triceps surae fatigue on lower extremity landing biomechanics. Sixteen healthy females (18–22 years) reported for testing on two occasions, with one muscle group fatigued per session. Subjects performed three single-leg landings onto a force platform pre- and post-fatigue, defined as an 80% decrease in peak torque in the targeted muscle group. Hip rotator fatigue was induced via alternating concentric contractions and triceps surae fatigue through concentric plantar flexion contractions on an isokinetic dynamometer. Initial contact (IC) kinematics and peak stance (PS) kinetics and kinematics were analyzed pre- and post-fatigue. Hip rotator fatigue increased IC ( P =0.05) and PS ( P =0.04) hip internal rotation angles. Triceps surae fatigue decreased IC knee flexion ( P =0.01) angle. Isolated hip rotator and triceps surae fatigue each produced modifications in lower limb kinematic parameters viewed as risk factors for ACL injury. These modifications, however, do not appear of sufficient magnitude to compromise ligament integrity, suggesting injury via an integrative lower extremity fatigue mechanism is more likely.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78722/1/j.1600-0838.2009.01076.x.pd

IO3- and I- Sorption from Groundwater by Layered Double Hydroxides

Several subsurface water plumes are found at the Hanford U.S. DOE site. These plumes contain many different types of hazardous components including radioactive iodate (IO3-) and iodide (I-), which may have deleterious health effects. To selectively uptake IO3- and I-, inorganic layered double hydroxide (LDH) compounds were synthesized and tested. LDHs are mixed transition metal hydroxides that contain positively charged layers that undergo anion exchange. When LDHs are submerged in the plume water, they can selectively uptake IO3- and I- and remove them from the plume. Raman spectroscopy was used to monitor the uptake of IO3- and I-. The thermodynamic properties of the LDHs were determined by differential scanning calorimetry (DSC), where a phase transition was observed in the thermogram of each LDH compound. The thermodynamic properties describe the temperature range where the LDH compounds are stable and uptake the highest concentration of IO3- and I-. Raman spectroscopy indicated which LDH compounds were the most selective for IO3-. Further experiments will be performed to determine IO­3- and I- sorption of LDH compounds in groundwater. Similar technology can then be applied to radioactive waste where interferences from other compounds are present

Network Leadership and Practice: Lessons From the Savory Global Network

This report summarizes findings from a five-year partnership between University of Colorado Boulder researchers and the Savory Global Network team. The aim of this report is to highlight five key themes around network leadership and practice identified over the course of studying Savory Global Network activities.</p