Mobile Network Evolution – “The Return of the Pipe”

The mobile network evolution from second generation to third generation systems has opened possibilities for inclusion of new technologies both in the network infrastructure as well as on the radio access. Within this paper, we concentrate on the evolution of the network infrastructure towards a future mobile network that balances the demand for increased flexibility with the necessity of limiting system complexity. Based on existing architectures, to lower complexity such as layered architecture for the core network and mobile packet backbone, we describe one possible evolution path for the control layer. Our approach is a step towards a control space that includes packetpipe control functions for a multitude of packetpipes. Such control function needs to be supported in the heterogeneous networks of today and the future.     

High-throughput mass spectrometer using atmospheric pressure ionization and a cylindrical ion trap array

The analytical performance of an atmospheric pressure sampling, multiple-channel, high-throughput mass spectrometer was investigated using samples of a variety of types. The instrument, based on an array of cylindrical ion traps, was built with four independent channels and here is operated using two fully multiplexed channels (sources, ion optics, ion traps, detectors) capable of analyzing different samples simultaneously. Both channels of the instrument were incorporated within the same vacuum system and operated using a common set of control electronics. A multichannel electrospray ionization source was assembled and used to introduce samples including solutions of organic compounds, peptides, and proteins simultaneously into the instrument in a high-throughput fashion. Cross-talk between the channels of the instrument occurred in the detection system and could be minimized to 1-2% using shielding between detector channels. In this initial implementation of the instrumentation, an upper mass/charge limit of approximately 1300 Th was observed (+13 charge state of myoglobin) and unit mass/charge resolution was achieved to approximately 800 Th. The rather limited dynamic range (2-3 orders of magnitude for low-concentration analytes) is due to cross-talk contributions from more concentrated species introduced into a different channel. Analysis of mixtures of alkylamines and peptides is demonstrated, but analysis of mixtures with a wide spread in mass/charge ratios was not possible due to mass discrimination in the ion optics. Further refinement of the vacuum system and ion optics will allow the addition of more channels of parallel mass analysis and facilitate applications in fields such as proteomics and metabolomics.     

On the nature of the fourth sound

The density-density correlation function of He II bounded by solid walls is calculated in the hydrodynamic region. The migration of its poles as a function of the resistance parameter is investigated, and it is found that the fourth-sound pole can only be related to the first-sound pole far enough (_s0/₀>1/9) from the critical temperature. Otherwise, it arises from a mixture of the first- and second-sound poles. The contributions of poles to the sum rules are also discussed.     

Stochastic modelling of individual cell growth using flow chamber microscopy images

In this paper, we analysed individual cell growth images obtained by flow chamber microscopy system. We used replicate flow chamber experiment data as reported by [Elfwing, A., Le Marc, Y., Baranyi, J., Ballagi, A., 2004. Observing the growth and division of large number of individual bacteria using image analysis. Applied and Environmental Microbiology 70, 675-678] involving both unstressed and heat shocked Listeria innocua cells. After observing the kinetics of a large number of cells, we propose a new stochastic model for their individual growth. By comparing our model with other existing models in the literature, we demonstrate that ours can accurately describe the growth of both stressed and unstressed cells. Our results indicate that the lag period, in terms of cell division, coincides dominantly with a lag period in terms of cell size. We also reveal various connections between cell length, lag time and cell division models. Finally, we present the results of our investigation on the effect of the duration of sublethal heat shock on the found growth properties.     

Antimicrobial functionalization of Ca alginate-coconut oil latent heat storing microcapsules by Ag nanoparticles

Latent heat storage by phase change materials (PCM) is a promising way of thermal energy storage for equilibrating the daily fluctuation of temperature in office- and home buildings. Bio-originated compounds have got great importance to evade further plastic contamination all over the world. Durability of biodegradable natural materials by means of environmentally friendly agents is an exciting challenge. In this study Ca alginate-coconut oil eco-friendly core-shell PCM microcapsules were functionalized with Ag nanoparticles, following their synthesis using harmless reducing agents. Throughout the preparation of the PCM microcapsules by repeated interfacial coacervation/crosslinking procedure, the Ag nanoparticles were homogeneously dispersed in the Ca alginate shell. High coconut oil content was achieved in the Ag nanoparticle-loaded microcapsules, which was not influenced by the Ag nanoparticle content. The high PCM content resulted in correspondingly high latent heat storing capability. The freezing and melting heat storing capacities were in the range of 83.6 and 85.6 J/g, as well as 89.7 to 92.6 J/g, respectively, matching to the extremely high PCM content in the range of 82.7% to 84.8% (m/m). Leaking of the heat storing microcapsules was not observed after 200 heating-cooling cycles. The Ag nanoparticle content did not influence the PCM ratio of the microcapsules, although as expected their antimicrobial potential was significantly enhanced by it. The highest Ag nanoparticle loading, that was 1.3% (m/m) related to the total mass of microcapsules, exerted excellent antibacterial and antifungal impact.