Reaction-diffusion Model Describing the Morphogenesis of Urban Systems in the US

Urbanization is currently one of the greatest challenges facing mankind. In order to be able to anticipate the rapid changes in urban structures, models are in need, mapping the morphological development of these structures. In this paper we present an urban development model that is based on reaction diffusion equations and can be interpreted sociologically. We apply this model to the urban development of US-American cities and show that this very simple model can already map basic characteristics of urban development

mm-Wave operation of AlN/GaN-devices and MMICs at V- & W-band

This paper presents recent device and MMIC results of a 70 nm AlN/GaN-HEMT technology. Based on DC-transfer characteristics, a high saturated drain current of more than 1700 mA/mm, and a maximum transconductance of 470 mS/mm were measured for this technology. A transit frequency of ft = 110 GHz along with a maximum oscillation frequency f max = 300 GHz has been extracted. A maximum PAE of 60 %, and a maximum output power density of more than 2.6 W/mm have been demonstrated on single-device level by performing load-pull measurements. The achieved device performance is further verified based on circuit level by the realization of two power amplifiers. MMIC 1 demonstrates a high saturated output power of more than 30 dBm (1 W) between 70-86 GHz. A maximum output power of P out = 28.5 dBm (700 mW) was determined at 94 GHz for MMIC 2

A “Vortex of Identities”: Freemasonry, Witchcraft, and Postcolonial Homophobia

The recent moral panic in Cameroon about a supposed proliferation of “homosexuality” is related to a special image of “the” homosexual as un Grand who submits younger persons, eager to get a job, to anal penetration, and are thus corrupting the nation. This image stems from the popular conviction that the national elite is deeply involved in secret societies like Freemasonry or Rosicrucianism. The tendency to thus relate the supposed proliferation of homosexuality in the postcolony to colonial impositions is balanced by other lines in its genealogy—for instance, the notion of “wealth medicine,” which Günther Tessmann, the German ethnographer of the Fang, linked already in 1913 to same-sex intercourse. This complex knot of ideas and practices coming from different backgrounds can help us explore the urgent challenges that same-sex practices raise to African studies in general. The Cameroonian examples confuse current Western notions about heteronormativity, GLBTQI+ identities, and the relation between gender and sex. Taking everyday assemblages emerging from African contexts as our starting point can help not only to queer African studies, but also to Africanize queer studies. It can also help to overcome unproductive tendencies to oppose Western/colonial and local/ traditional elements. Present-day notions and practices of homosexuality and homophobia are products of long and tortuous histories at the interface of Africa and the West

Broadband GaN-based power amplifier MMIC and module for V-band measurement applications

This work presents a balanced GaN-based power amplifier targeting the entire V-band frequency range. The fabricated chip was packaged in a split block WR-15 waveguide environment to make it applicable for high-power measurement applications. The designed GaN MMIC provides a high small signal gain of more than 20 dB within a frequency range of 49 GHz up to 83 GHz. On-wafer large-signal measurements of the MMIC at 75 GHz demonstrate a linear gain of 26.3 dB, along with a saturated output power of 29.3 dBm (850 mW) and a maximum power added efficiency of 13.5 %. For the assembled module, an average saturated output power of 28.1 dBm (645 mW) within a variance of ±0.4 dB has been measured for the entire V-band (50-75 GHz)

A 300 GHz low-noise amplifier S-MMIC for use in next-generation imaging and communication applications

A WR-3 (220- 330 GHz) low-noise amplifier (LNA) circuit has been developed for use in next-generation high resolution imaging applications and ultra-high capacity communication links. The submillimeter-wave monolithic integrated circuit (S-MMIC) was realized by using a 35 nm InAlAs/InGaAs based metamorphic high electron mobilittransistor (mHEMT) technology in combination with grounded coplanar waveguide topology (GCPW) and cascode transistors, thus leading to a very low noise figure in combination with high gain and large operational bandwidth. The packaged LNA circuit achieved a maximum gain of 29 dB at 314 GHz and more than 26 dB in the frequency range from 252 to 330 GHz. An average room temperature (T = 293 K) noise figure of 6.5 dB was measured between 280 and 330 GHz. Furthermore, the LNA circuit has been used to realize a very compact WR-3 single-chip receiver module, demonstrating an average conversion gain of 6.5 dB and a noise figure of 8.6 dB at the frequency of operation

Bestandsaufnahme der Weiterbildung in Mecklenburg-Vorpommern 1992

Mit einer von BUeSTRO (Buero fuer Strukturforschung Rostock) von Mai bis August 1992 durchgefuehrten Untersuchung zur Weiterbildung in Mecklenburg-Vorpommern sollte ein moeglichst vollstaendiger und detaillierter Ueberblick ueber die Struktur der Bildungseinrichtungen und das Angebot an Massnahmen zur Verfuegung gestellt werden. An der Befragung beteiligten sich 350 Bildungstraeger; neben schriftlichen Befragungen von Kursteilnehmern (n=1.055) wurden in 82 Einrichtungen Interviews mit den Geschaeftleitungen, Dozenten und Lehrgangsteilnehmern gefuehrt. ' Bei der Bestandsaufnahme von Bildungstraegern werden folgende Aspekte beruecksichtigt: - die fachliche Ausrichtung der Traeger, - die regionale Struktur der Traeger, - die Kapazitaet der Traeger und die Auslastung der Kurse, -der Ausbildungsstandard des Lehrpersonals, Bildungstraeger, - die personelle und finanzielle Ausstattung der Traeger. Das Angebot an Massnahmen wird unter folgenden Gesichtspunkten erfasst: - nach der inhaltlichen Struktur des Bildungsangebots, differenziert nach Branchen und Berufen, - nach der Dauer der Massnahmen, Wort kommen auch die Teilnehmer an den Kursen, und zwar hinsichtlich - der Eingangsqualifikation, - der Einschaetzung des Lehrgangs bezueglich Qualitaet und Lernbedingungen, - der Zufriedenheit mit der Massnahme, - einer Einschaetzung des Kursbesuches im Hinblick auf kuenftige Arbeitsmarktchancen.' (IAB2)Available from IAB / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Testbed for phased array communications from 275 to 325 GHz

The first modular 4-channel frontend for exploring phased array communications at a carrier frequency of 300 GHz was developed. A metamorphic HEMT process with a gate length of 35 nm was the key enabling technology for the integration of each transmit and receive channel. All channels implemented the quadrature direct conversion architecture. The measured RF bandwidth exceeded 55 GHz for the receive array respectively 45 GHz for the transmit array using a continuous wave baseband test signal. Phase shifting in the local oscillator path was the focus of this work. The concept was realized by using four synchronized direct digital synthesis channels followed by a high power frequency multiplier-by-12 MMIC. Investigating and assessing the array coherency at 300 GHz by the use of higher order modulation schemes was also proposed, highlighted on the example of a 16-QAM signal at 4 Gbaud in comparison to phase noise measurements of each channel

Carbapenem-resistant Gram-negative bacteria – analysis of the data obtained through a mandatory reporting system in the Rhine-Main region, Germany, 2012–2015

Background: Multidrug-resistant Gram-negative bacteria (MRGN) and the infections they cause are a serious threat and a challenge to the healthcare system. This particularly applies to carbapenem-resistant Gram-negative bacteria (CRGN). Currently, the introduction of a nationwide mandatory notification system for CRGN in Germany is under consideration. Against this background, this paper presents an analysis of the mandatory reporting system for CRGN in effect since November 2011 in the federal state of Hesse (Germany). Materials and methods: All carbapenem-resistant Gram-negative bacteria and the detected carbapenemases reported to the public health department of the city of Frankfurt am Main, Hesse, Germany, on the basis of the mandatory notification system were analyzed.Results: 827 CRGN cases were reported to the public health department of Frankfurt/Main between April 2012 and December 2015. The following bacterial species were reported: spp. (n=268), spp. (n=183), spp. (n=195), spp. (n=77), (n=75) and others (n=29). Between 2012 and 2015, a reduction of the CRGN reports was noticed, mainly due to changes in the reporting of spp. Between 2012 and 2015, the total number of notifications decreased slightly, although the number of reported CRGN in screening samples increased, thus giving no indication of a decreased testing frequency. For 10.5% of the patients, the place of residence was not Germany, 18.0% of the patients had previously stayed in hospitals abroad, often in countries with a high CRGN prevalence. CRGN bacteria were reported from all of Frankfurt’s hospitals, and 3.9% were reported from out-patient care facilities. Carbapenemases were detected and reported in 251 CRGN bacteria, including 73 OXA-48, 76 OXA-23, 56 NDM subtypes, and 21 KPC subtypes. There have been no major epidemiological signs of outbreak scenarios.Discussion: CRGN bacteria are already widespread in patients from hospitals and out-patient care facilities. Clearly, infection control measurements should therefore not only include hospital patients but also those receiving out-patient care. Screening strategies focused on patients from foreign countries with high MRGN prevalence is not sufficient, as only 10.5% of MRGN patients resided in those countries, and only 18% of the patients had been previously treated in a foreign hospital. In a public health context, infection control measures should therefore encompass broader screening strategies