Impacts of new technologies on media usage and social behaviour in domestic environments

Technological infrastructure at home is changing continuously and is becoming increasingly interconnected. Media devices, including the TV set, provide access to the Internet and offer manifold opportunities to consume media on demand. Additionally, personal devices, such as smartphones, also enable flexible consumption and sharing of media. Questions about how these technologies change the user's media usage and how these changes affect the social structure of a household, however, remain largely unanswered. In order to gain insight into the adoption of new technologies into daily routines, we explored these changes in respect of people's media usage in a qualitative long-term Living Lab study. We will present findings regarding personal routines, flexible integration of new devices into existing practices, influences on households as social systems and related issues in device access and collective use. We will highlight potentials and conflicts regarding device shifts and roles; restrictions in device access; social influences in the living room; and individual changes in media consumption.     

Data collection in global software engineering research: learning from past experience

Global Software Engineering has become a standard in today’s software industry. Research in distributed software development poses severe challenges that are due to the spatial and temporal distribution of the actors, as well as to language, intercultural and organizational aspects. These challenges occur in addition to “traditional” challenges of the domain itself in large-scale software projects, like coordination and communication issues, requirements volatily, lack of domain knowledge, among others. While several authors have reported empirical studies of global software development projects, the methodological difficulties and challenges of this type of studies have not been sufficiently discussed. In this paper, we share our experiences of collecting and analysing qualitative data in the context of Global Software Engineering projects. We discuss strategies for gaining access to field sites, building trust and documenting distributed and complex work practices in the context of several research projects we have conducted in the past 9 years. The experiences described in this paper illustrate the need to deal with fundamental problems, such as understanding local languages and different cultures, observing synchronous interaction, or dealing with barriers imposed by political conflicts between the sites. Based on our findings, we discuss some practical implications and strategies that can be used by other researchers and provide some recommendations for future research in methodological aspects of Global Software Engineering.     

7-(Dialkylamino)coumarin-4-yl]methyl-Caged Compounds as Ultrafast and Effective Long-Wavelength Phototriggers of 8-Bromo-Substituted Cyclic Nucleotides

[7-(Dimethylamino)coumarin-4-yl]methyl (DMACM) and [7-(diethylamino)coumarin-4-yl]methyl (DEACM) esters of 8-bromoadenosine 3',5'-cyclic monophosphate (8-Br-cAMP) and 8-bromoguanosine 3',5'-cyclic monophosphate (8-Br-cGMP) are described as novel caged compounds for 8-bromo-substituted cyclic nucleotides. Synthesis is accomplished by treatment of the free acids of the cyclic nucleotides with the corresponding 7(dialkylamino)-substituted 4(diazomethyl)coumarins. Irradiation of the DMACM- and DEACM-caged cyclic nucleotides with UV light stimulates the release of the cyclic nucleotides within roughly a nanosecond. The new caged compounds are resistant to hydrolysis in aqueous buffers and exhibit long-wavelength absorption properties with maxima at 400 nm, high extinction coefficients, and high quantum yields (0.15-0.31). Their favorable properties render these compounds the most efficient and rapid phototriggers of 8-bromo-substituted cyclic nucleotides known. The usefulness of the compounds for physiological studies under nondamaging light conditions was examined in HEK293 cells expressing the alpha subunit of the cyclic-nucleotide-gated (CNG) channel of cone photoreceptors (CNGA3) and of olfactory neurons (CNGA2) by using confocal laser scanning microscopy and the patch clamp technique.     

Reduction of NOx by H2 on WOx-Promoted Pt/Al2O3/SiO2 Catalysts Under O2-Rich Conditions

This work addresses the reduction of NO_x by H₂ under O₂-rich conditions using Al₂O₃/SiO₂-supported Pt catalysts with different loads of WO_x promotor. The samples were thoroughly characterised by N₂ physisorption, temperature-programmed desorption of CO, scanning electron microscopy, X-ray diffraction, laser raman spectroscopy, X-ray photoelectron spectroscopy and diffuse reflectance infrared fourier transform spectroscopy with probe molecule CO. The catalytic studies of the samples without WO_x showed pronounced NO_x conversion below 200 °C, whereas highest efficiency was related to small Pt particles. The introduction of WO_x provided increasing deNO_x activity as well as N₂ selectivity. This promoting effect was referred to an additional reaction path at the Pt-WO_x/Al₂O₃/SiO₂ interface, whereas an electronic activation of Pt by strong metal support interaction was excluded.

Graphic Abstract

     

Compatibilisation of PPE/SAN blends by triblock terpolymers: Correlation between block terpolymer composition, morphology and properties

Immiscible blends of poly(2,6-dimethyl-1,4-phenylene ether) (PPE) and poly(styrene-co-acrylonitrile) (SAN) with a weight composition of 60/40 were compatibilised by polystyrene-block-polybutadiene-block-poly(methyl methacrylate) triblock terpolymers (SBM) using a two-stage melt-processing approach. In order to investigate the influence of the SBM composition on the compatibilisation efficiency, the block lengths of the triblock terpolymers were systematically varied. The resulting morphological features of the blend systems as function of SBM composition and processing parameters are correlated with the resulting thermal and thermo-mechanical properties. In the ideal case, SBM should be located at the interface as PS is miscible with PPE while PMMA is miscible with SAN. The elastomeric middle block as an immiscible component should remain at the interface. This particular morphological arrangement is known as the ‘raspberry morphology’. A detailed TEM analysis of the blend morphologies following initial extrusion-compounding revealed a high compatibilisation efficiency of the SBM types with equal lengths of the end blocks and, furthermore, the desired raspberry morphology was achieved. In contrast, high PS contents in comparison to the other blocks led to a pronounced micelle formation in the PPE phase. Further evaluation of the blend structures following injection-moulding indicated that the morphologies remain relatively stable during this second melt-processing step. A detailed thermal analysis of all blend systems supports the interpretation of the observed morphological features. The fundamental correlation between SBM composition and blend morphology established in this study opens the door for the controlled development of interfacial properties of such compatibilised PPE/SAN blends during melt-processing.     

Liquid flow and phase holdup—measurement and CFD modeling for two-and three-phase bubble columns

Bubble columns are an important class of contacting devices in chemical industry and biotechnology. Their simple setup makes them ideal reactors for two- and three-phase operations such as fermentations or heterogeneous catalysis. Still, design and operation of these reactors is subject to widely empirical scale-up strategies. With recent advances in the development of measurement techniques, a more detailed approach to the development of optimized reactors for specific operations should become possible. This report is based on detailed measurements of local dispersed phase holdups in a pilot plant-sized bubble column operated at high superficial gas velocities and solid holdups. It deals with the influence of superficial gas velocity, solid loading and sparger geometry on measured and computed liquid flow velocities and holdup distributions. Liquid velocity measurements have been performed using the electrodiffusion method, modeling calculations have been carried out using the computational fluid dynamics (CFD) code CFX-4.3. Measurement results presented here give an insight into the development of liquid circulation and fluctuating velocity distribution depending on superficial gas velocity, solid loading and sparger geometry. CFD results implementing a multi-fluid model with k-ε turbulence and special momentum exchange terms for direct gas-solid interactions show that, even on standard PC workstations, this kind of computations can deliver qualitatively reasonable agreement with measurements.     

Extended bisection method for parameter identification of the transient heat conduction equation for thermo-elastic deformations during drilling

A new interdisciplinary approach is discribed to identifying unknown parameters using an extended version of the known interval bisection method. This developed method is based on the use of finite elements for calibrating the simulation calculation. The resulting thermo-elastic deformations which occur in drilling processes with impaired cooling lubrication are to be used as correction values for tool positioning in the NC control. Based on the strong impact on workpiece temperature of machining, a simulation approach is presented for calculating the temperature fields and their thermo-elastic consequences. In addition, methods are presented to correct these effects. This paper particularly deals with the temperature fields of drilling operations. Special attention is paid to the technique employed for iterative numerical determination of the unknown heat flux η _w and heat transfer coefficient \(\bar {\gamma }\) values. Finally, the data obtained from experiments are compared with those achieved by numerical simulation in order to verify the efficiency of simulation and determination of parameters.     

State of the Art Treatment of Non-Ferrous Castings 3-in-1 Heat Treatment Systems Combine Foundry Processes

The interior of a high-pressure die-casting is of an unsatisfactory quality. Engine blocks made with this die casting process show lower specific engine performance. Pressure die-casting can hardly be heat treated for obvious reasons PSM (Precision Sand Molds) process uses sand and organic binder to generate a mold and even allows the manufacturing of complex diesel engine blocks in aluminum alloys. Combined technologies are available for semi-permanent mold castings with cores and castings made in Precision Sand Molds with organic binders. Castings are placed into the special heat treatment furnace immediately after pouting without the operations in stand alone machinery. This patented Sand Lion^R 3-in-1 technology processes hot castings and carries out three (3) foundry processes simultaneously in one (1) automated machine: 1) De-coring and sand removal; 2) Thermal sand reclamation; 3) Solution heat treatment of castings. The combination of several main casting processes is reflected in significant reductions of energy consumption, of production costs, and improving the quality of the castings. Audits in foundries using the 3-in-1 process showed an average reduction in production costs of more than 30%.     

“From microtiter plates to droplets” tools for micro-fluidic droplet processing

Droplet-based microfluidic allows high throughput experimentation in with low volume droplets. Essential fluidic process steps are on the one hand the proper control of the droplet composition and on the other hand the droplet processing, manipulation and storage. Beside integrated fluidic chips, standard PTFE-tubings and fluid connectors can be used in combination with appropriate pumps to realize almost all necessary fluidic processes. The segmented flow technique usually operates with droplets of about 100–500 nL volume. These droplets are embedded in an immiscible fluid and confined by channel walls. For the integration of segmented flow applications in established research workflows—which are usually base on microtiter plates—robotic interface tools for parallel/serial and serial/parallel transfer operations are necessary. Especially dose–response experiments are well suited for the segmented flow technique. We developed different transfer tools including an automated “gradient take-up tool” for the generation of segment sequences with gradually changing composition of the individual droplets. The general working principles are introduced and the fluidic characterizations are given. As exemplary application for a dose–response experiment the inhibitory effect of antibiotic tetracycline on Escherichia coli bacteria cultivated inside nanoliter droplets was investigated.