Nonequilibrium and hysteretic low temperature dielectric response to strain in glasses

We present data on the nonequilibrium ac dielectric response of amorphous insulators to the application of a quasi-dc mechanical strain field below 150 mK. The behavior of the system after perturbation by a strain field is analogous to that observed after the application of a dc electrical field. In the current theoretical framework the nonequilibrium response is due to a time dependent density of states correction resulting from TLS-TLS interactions. In addition, an anomalous hysteresis in fast strain and electric field sweeps is reported which may represent the predicted dynamical response of relaxing independent TLS.     

Personalisierung in der E-Welt Aus dem Blickwinkel der informationellen Selbstbestimmung gesehen

Personalisation in the E-World — Seen from the Perspective of Informational Self-Determination Compared to the material world, data traces will to an increasing degree be used for the purpose of personalisation in the e-world. The article examines both the risks for the self-determination of the data subject and the safeguards of data protection law in this world. It is apparent that the requirements of data protection law are frequently not observed. However, the law is able to form the legal basis of necessary personalisations and to protect the data subject if this process is carried out without his/her consent. It is important to distinguish these single processes from the accumulating effects of ubiquitous electronic personalisation. The latter form fundamental problems for democratic societies, and data protection laws do not have the ability to solve these issues. In contrast, there is a strong need for the separation between personalisation and control on a technical level.

Eingereicht am 2006-09-17, nach überarbeitung angenommen am 2006-09-22 durch die Herausgeber des Schwerpunktheftes.     

Evaluating and improving environmental performance of HC's recovery system: A case study of distillation unit

Waste solvents/valuable products in the effluent stream are one of the major environmental problems in the chemical industry if not properly controlled. Separation processes are vital for the recovery of waste solvent/valuable product from the effluent stream to reduce the pollution along with improvement in economic performance. Among the various separation processes, distillation is most widely used. A number of environmental indicators, each satisfying researchers own need, and methodologies such as life cycle assessment (LCA), minimum environmental impact assessment (MEIM), waste reduction algorithm (WAR) and environmental fate and risk assessment (EFRAT) are available for evaluation of environmental performance of chemical processes. In this article, a systematic procedure, introducing an environmental performance index (EPI) based on potential environmental impact (computed from waste reduction algorithm (WAR)), energy consumption, resource conservation and fugitive emission, for evaluating environmental performance is presented. Analytical hierarchy process (AHP) is used at two levels for the determination of weighting of individual categories. The procedure is applied for the study of environmental performance of distillation column (steam stripping column) from a real chemical plant for the recovery of acetone and HC's from the off gases of the distillation fraction (DF) plant. Alternatives are compared using environmental performance index and best alternative is selected.     

Planning - topography and climate

The presentation of local climatic data has wide-reaching effects for planners, designers and those living and working in an area, report Sven Lindqvist and Jan O. Mattsson of the Department of Geography at the University of Lund.     

Compounding, micro injection moulding and characterisation of polycarbonate-nanosized alumina-composites for application in microoptics

The addition of nanosized ceramics to polymers allows for a tailoring of the thermomechanical and optical properties of the used thermoplastic matrix polymers. In this work, the impact of nanosized γ-alumina filler to polycarbonate APEC2097 on the compounding process and the resulting physical properties is reported. Polymer degradation during compounding affects a plasticising effect and a reduction of the Charpy impact strength. The refractive indices of the polycarbonate-alumina-composites increase with increasing solid load. Due to nanoparticle agglomeration the optical transmittance drops with growing alumina content.     

A method for identifying Web applications

Web applications are ubiquitous in today’s businesses. The security of these applications is of utmost importance since security breaches might negatively impact good reputation, and even result in bankruptcy. There are different methods of assessing security of Web applications, mainly based on some automated method of scanning. One type of scan method feeds random data to the application and monitors its behavior. The other type uses a database with predefined vulnerabilities that are checked one by one until either a vulnerability is found, or it can be claimed that the application does not have any known vulnerabilities. The important step in latter type of scan process is the identification of the application since in this case we are narrowing number of checks and, as a consequence, the scan process is faster. This paper describes a method for Web application identification based on a black box principle. Our method is based on the invariance of certain characteristics of Web applications. We experimentally tested and confirmed the usefulness of this approach.     

Fabrication of RF MEMS variable capacitors by deep X-ray lithography and electroplating

Radio frequency micro electro-mechanical systems (RF MEMS) vertical cantilever variable capacitors fabricated using deep X-ray lithography and electroplating are presented. Polymethylmethacrylate (PMMA) layers of 100 μm and 150 μm have been patterned and electroplated with 70 μm and 100 μm thick nickel. A 3 μm thick titanium layer was used as plating base as well as etch time-controlled sacrificial layer for the release of the cantilever beam. The parallel plate layout includes narrow gaps and cantilever beams with an aspect ratio in nickel of up to 60 for 1 mm long features. Auxiliary structures support the beams and gaps during the processing. Room temperature electroplating significantly reduces the risk of deformations compared to the standard process temperature of 52°C. The capacitors operate in the 1–5 GHz range, and demonstrate good RF performance, with quality factors on the order of 170 at 1 GHz for a 1 pF capacitance.