Copolymers from 1-phenyl-2-(3-vinylphenylthio)-diazen and styrene and grafting with acrylonitrile

Summary A new azo monomer (2) was synthesized and copolymerized with styrene. The resulting azo copolymer could be used as an initiator for the acrylonitrile polymerisation yielding grafted copolymers. Quantitative treatment of the grafting experiments leads to the conclusion that the intermediate thiyl radicals show less reactivity towards monomers than phenyl radicals.     

Field-implant-free isolation by double-well split drive-in

A double-well CMOS concept well suited to conventional and state-of-the-art isolation techniques is presented. Sufficient field doping is achieved by solely distributing the well drive-in thermal budget before and after field oxidation. Segregation effects, in particular dopant loss in the p-well, are compensated. At the same time the body factor and parasitic capacitances are kept low. The split drive-in approach makes channel-stop implants and corresponding lithography steps superfluous. The field doping adjustment is self-aligned, a very significant advantage in submicrometer regime processing     

Interventricular septal motion in patients with proximal and distal left anterior descending coronary artery lesions

In order to evaluate the ability of the echocardiogram to detect and localize left main or left anterior descending (LAD) coronary artery lesions, 43 patients were studied. The systolic excursion of the left side of the septum and the ratio of posterior wall to septal excursion were measured. Seventeen patients had no LAD lesions; all had systolic septal excursion of 3 mm or greater. Twelve patients with septal excursion of 2 mm or less all had left main or LAD lesions, but 14 other patients with LAD lesions had septal excursions of 3 mm or greater. Nine of 16 patients with LAD lesions proximal to the first septal branch had reduced or absent septal excursion, as did three of ten with LAD lesions distal to the first septal branch. In a setting of coronary artery disease reduced or absent septal motion on echocardiography suggests involvement of the left main or left anterior descending coronary. However, the technique is relatively insensitive, with 54% of the LAD patients having normal septal motion.     

The influence of p-polysilicon gate doping on the dielectric breakdown of PMOS devices

The influence of the gate electrode p-polysilicon doping concentration on gate oxide breakdown data is investigated. It is shown that a small variation in doping concentration of p-doped polysilicon gates as well as an inversion layer in p-polysilicon gate strongly affects the results, if PMOS devices are stressed in inversion biasing mode by applying a constant current stress.     

SiC encapsulation of (V)HTR components and waste by laser beam joining of ceramics

From the technological point of view as well as under the aspect of increasing safety requirements high-temperature resistant materials gain increasing importance in the nuclear sector. The non-oxide ceramics are characterized by their truly unusual properties. In this field high-tech ceramics such as silicon carbide (SiC) and silicon nitrite (Si₃N₄) play an outstanding role. However, their application used to be limited by the lack of a really suitable joining technology for high-temperature applications.At the Dresden University of Technology (TUD) an innovative laser beam joining technology for these ceramics has been developed in a joint project over the last few years. This technology makes it possible to join SiC as well as Si₃N₄ ceramics with high-temperature resistant, vacuum-tight seams that are resistant to most chemical substances. As no protective atmosphere is needed and the joining process takes less than a minute, the complete joining process can be configured very efficiently also in economic terms.For demonstration of the new possibilities SiCeram GmbH has developed several ceramic components which are tailored to V(HTR) requirements in material and geometries. Examples will be demonstrated.The overall ceramic encapsulation of fuel particles provides an additional thick barrier against the release of fission products, increasing the margins for operation at very high temperatures. Simultaneously ceramic encapsulation of the main core components facilitates the approach to the non-catastrophic behaviour of (V)HTR. Additional future research and the qualification of SiC encapsulated pebbles or compacts may result in important benefits also for waste management and final storage.     

Vergleichende Untersuchung raumakustischer Konzepte von Mehrpersonenbüros hinsichtlich Sprachverständlichkeit,Arbeitsgedächtnisleistung und Arbeitsbehaglichkeit durch Hörversuche

Comparative studies of room‐acoustic concepts for open‐plan offices with regard to speech intelligibility, short‐term memory perfomance and acoustic comfort. Increasing use of tempering the core of reeinforced concrete ceilings of open‐plan offices for cooling and if necessary for heating strongly limits the implementation of sound‐absorbing ceilings. In these cases the classic concept for offices with fully sound‐absorbing ceilings and screen barriers is not applicable anymore. As an alternative to this concept of screen barriers a so‐called partition wall concept is going to be implemented in these open‐plan offices. In this case a sound‐absorbing ceiling is not used anymore; instead room‐high partition walls are mounted, which are highly sound‐absorbing on both sides. The objective of the study was to compare these two concepts for open‐plan offices regarding speech intelligibility on the phone, ability to concentrate and acoustic comfort. In addition to that the effect of low‐frequency absorbers was investigated. To evaluate the acoustic concepts of theses offices audibility tests were conducted. For this purpose the room‐acoustic conditions of the office situations were auralized with the help of measured binaural room impulse responses of original open‐plan offices. For comparison an open‐plan office without room‐acoustic measures was included. With this procedure different office situations are directly comparable.     

Assessing oxide reliability targets with fast WLR measurements

In this article, oxide reliability targets are discussed, and the significance of the extrinsic branch of a bimodal Weibull plot is critically described. The slope of the extrinsic branch plays an important role, and it is demonstrated that a worst case slope can be determined for extrapolation purpose. A strategy is laid out for the confirmation of the oxide reliability requirements.     

Prevalence of internet addiction in the general population: results from a German population-based survey

Despite a growing number of publications, there is still no generally agreed-upon definition and assessment procedure for Internet addiction, and there is a lack of representative data on its prevalence in the general population. Based on a reliable and valid scale of Internet addiction, the purpose of this study was to determine the proportion of the general population of Internet addiction with psychometric evidence and to identify associated psychosocial and health consequences. Out of a representative survey of the German population (N=2512) the leisure time Internet users (n=1382) were queried by standardised questionnaires on Internet addiction, depression, anxiety (HADS) and depersonalisation (CDS-2). According to strict criteria of the Assessment of Internet and Computer Game Addiction (AICA-S), 2.1% of the sample was characterised as addicted by meeting criteria of craving, withdrawal symptoms, tolerance, etc. These reported daily Internet use, excessive online times. The majority reported additional adverse psychosocial and health consequences. Risk factors were male gender and social factors (unmarried, unemployment, students, low income). Online gambling, social networks, gaming chats and pornography were preferentially used by Internet addicts. Assessment of Internet addiction requires a multifaceted approach; the AICA-S is an instrument suitable for further epidemiological study.     

Orts- und temperaturabh?ngige W?rme��bergangskoeffizienten bei der Spr��hk��hlung von AlSi10Mg-Gussplatten

The purpose of the current investigations is the measurement and modelling of the heat transfer coefficients?? spatial and temperature dependency, which are determined for the spraying properties of circular and flat fan nozzles. Thermographically measured cooling curves from spray-cooled discs of an AlSi10Mg aluminium cast-alloy serve as data for calculating the heat transfer coefficients. The computation is carried out by means of a model which uses the series solution for a semi-infinite plate. The heat transfer coefficients could be determined and modelled as a function of both the location of an impinging spray on a plate??s surface as well as the surface temperature. The influence of the spraying parameters air pressure and water pressure as well as the test piece temperature on the heat transfer coefficients, which were observed in other research, is confirmed.