Fearless: Professor Janet Powers and Linnea Goebel

This week we would like to recognize Professor Janet Powers and recent graduate Linnea Goebel ’13 for their work in Bosnia this summer helping to set up a group of female embroiderers with an Amazon Marketplace account to sell their wares on the internet. [excerpt

Real income rose significantly between 1991 and 2014 on average: First indication of return to increased income inequality

The real disposable income of private households in Germany, accounting for inflation, rose by 12 percent between 1991 and 2014. This is what the present study based on data from the Socio-Economic Panel (SOEP) has shown. However, the trends varied greatly depending on income group. While the middle income segment rose by more than eight percent, the highest income segment increased by up to 26 percent. The lower income segment, on the contrary, declined in real terms. Consequently, income inequality has increased overall, especially in the first half of the 1990s, in the period from 1999 to 2005, and after 2009. It stagnated or even decreased in the interim periods. The proportion of people at risk of poverty has recently become greater again. Gainful employment still provides the most effective protection against income poverty, but more and more employed persons are at risk of becoming poor. Containment of the low wage sector, by revoking the privileged status of mini-jobs, for example, could counteract this effect. And single parents should no longer be fiscally disadvantaged in comparison to childless coupled households - this could also reduce the number of children at risk of poverty

Reduction in income inequality faltering

Inequality of disposable incomes in Germany has decreased slightly since its peak in 2005. However, this trend did not continue in 2011. The most important reasons for this were the inequality in market incomes, including capital incomes, which had increased again. Besides this finding, the updated analyses of personal income distribution based on the Socio-Economic Panel Study (SOEP) show that the risk of poverty did not rise further after a long period of upward movement. Income mobility over time is equally important in terms of social policy, i.e., the upward or downward movement of individual groups of people in the income hierarchy. Here, the most recent analyses confirm the trend of significantly decreasing income mobility since German reunification. For example, the odds of exiting the risk of poverty within a period of four years has dropped by ten percentage points to 46 percent in recent years

Performance of charge-injection-device infrared detector arrays at low and moderate backgrounds

Three 2 x 64 element charge injection device infrared detector arrays were tested at low and moderate background to evaluate their usefulness for space based astronomical observations. Testing was conducted both in the laboratory and in ground based telescope observations. The devices showed an average readout noise level below 200 equivalent electrons, a peak responsivity of 4 A/W, and a noise equivalent power of 3x10 sq root of W/Hz. Array well capacity was measured to be significantly smaller than predicted. The measured sensitivity, which compares well with that of nonintegrating discrete extrinsic silicon photoconductors, shows these arrays to be useful for certain astronomical observations. However, the measured readout efficiency and frequency response represent serious limitations in low background applications

Detector arrays for low-background space infrared astronomy

The status of development and characterization tests of integrated infrared detector array technology for astronomy applications is described. The devices under development include intrinsic, extrinsic silicon, and extrinsic germanium detectors, with hybrid silicon multiplexers. Laboratory test results and successful astronomy imagery have established the usefulness of integrated arrays in low-background astronomy applications

Study of the performance and capability of the new ultra-fast 2 GSample/s FADC data acquisition system of the MAGIC telescope

In February 2007 the MAGIC Air Cherenkov Telescope for gamma-ray astronomy was fully upgraded with an ultra fast 2 GSamples/s digitization system. Since the Cherenkov light flashes are very short, a fast readout can minimize the influence of the background from the light of the night sky. Also, the time structure of the event is an additional parameter to reduce the background from unwanted hadronic showers. An overview of the performance of the new system and its impact on the sensitivity of the MAGIC instrument will be presented.Comment: Contribution to the 30th ICRC, Merida Mexico, July 2007 on behalf of the MAGIC Collaboratio

HOLLOTRON switch for megawatt lightweight space inverters

The feasibility of satisfying the switching requirements for a megawatt ultralight inverter system using HOLLOTRON switch technology was determined. The existing experimental switch hardware was modified to investigate a coaxial HOLLOTRON switch configuration and the results were compared with those obtained for a modified linear HOLLOTRON configuration. It was concluded that scaling the HOLLOTRON switch to the current and voltage specifications required for a megawatt converter system is indeed feasible using a modified linear configuration. The experimental HOLLOTRON switch operated at parameters comparable to the scaled coaxial HOLLOTRON. However, the linear HOLLOTRON data verified the capability for meeting all the design objectives simultaneously including current density (greater than 2 A/sq cm), voltage (5 kV), switching frequency (20 kHz), switching time (300 ns), and forward voltage drop (less than or equal to 20 V). Scaling relations were determined and a preliminary design was completed for an engineering model linear HOLLOTRON switch to meet the megawatt converter system specifications