Line creep in paper peeling

The dynamics of a “peeling front” or an elastic line is studied under creep (constant load) conditions. Our experiments show in most cases an exponential dependence of the creep velocity on the inverse force (mass) applied. In particular, the dynamical correlations of the avalanche activity are discussed here. We compare various avalanche statistics to those of a line with non-local elasticity, and study various measures of the experimental avalanche-avalanche and temporal correlations such as the autocorrelation function of the released energy and aftershock activity. From all these we conclude, that internal avalanche dynamics seems to follow “line depinning”-like behavior, in rough agreement with the depinning model. Meanwhile, the correlations reveal subtle complications not implied by depinning theory. Moreover, we also show how these results can be understood from a geophysical point of view.     

A Novel Environment Characterization Metric for Clustered MIMO Channels

In this work we introduce a novel metric for characterizing the double-directional propagation environment and use this metric to assess the performance of a SAGE parameter estimator for MIMO channels. Using the IlmProp, a geometry-based MIMO channel modeling tool, we construct synthetic channels for three different scenarios showing: (i) well separated clusters containing dense propagation paths, and single-bounce scattering; (ii) partly overlapping clusters containing widely spread propagation paths, and single-bounce scattering; (iii) unclustered multipath components (“rich scattering”), and double-bounce-only scattering. We model the scatterers and the receiver in the environment as fixed, but the transmitter as moving. The Initialization and Search-Improved SAGE (ISIS) estimation tool is used to extract the propagation paths from the constructed channels. Both true and estimated paths are fed to the new system-independent metric which genuinely reflects the structure of the channel and the compactness of the propagation paths. We use this metric to decide on the accuracy of the channel estimator. The results show a convincing agreement between true and estimated paths.     

Near-Infrared Laser-Induced Decomposition of C60 Dissolved in Toluene

In this paper we describe the efficient and substantial decomposition of C₆₀ in toluene solution, induced by moderate intensity (I = 20 - 55 MW cm^-2) near infrared (γ = 1064 nm) laser radiation. This behavior is surprising since both uncharged fullerene and toluene do not have any absorption bands at this wavelength. The decomposition efficiency and products are investigated with UV-Vis absorption spectrophotometry and high-performance liquid-chromatography (HPLC). Possible mechanisms of the fullerene decomposition are discussed.     

Effect of curing process on simulated antisoiling properties of sol–gel coating on pine sapwood

Recently, inorganic–organic hybrid coatings produced by the sol–gel route have proven to be a potential protective treatment for wooden surfaces. In this study, the effect of curing process on simulated antisoiling properties of sol–gel coating was investigated. The sol–gel coating was spray-coated on pine sapwood and cured with different temperature and time combinations. The antisoiling properties were studied by measuring the water contact angle of the coating after different curing processes. In addition, abrasion resistance and contact angle of oleic acid were measured. An optical profilometer was used to investigate surface roughness of the coating. Sufficient hydro- and oleophobicity were obtained with all of the curing parameters. The comparison between curing parameters showed that lower temperature and 1–3 h curing time leads to significant improvement in the durability of the water and oil repellent properties of the coating.     

A qualitative H NMR study of CHCl3 adsorption on conjugated acid–base pairs in cation exchanged Y-zeolites

Solution state ¹H NMR is employed to study the mode and strength of chloroform adsorption on conjugated acid–base pairs of cation-exchanged Y-zeolites. ¹H NMR results indicate that two different surface bonding orientations may exist. An acidic hydrogen site of zeolite favours orientation where the chloroform hydrogen points towards the zeolite cage centre. An exchanged electropositive cation increases the basicity of framework oxygens of zeolite and directs the chloroform to adsorb on framework oxygens with a hydrogen bond. In this adsorption site the chemical shift of the chloroform hydrogen has a linear dependence on the electronegativity of the cation.     

Role of Bose enhancement in photoassociation

Abstract

We discuss the role of Bose enhancement of the dipole matrix element in photoassociation, using stimulated Raman adiabatic passage as an example. In a non-degenerate gas the time scale for coherent optical transients tends to infinity in the thermodynamic limit, whereas Bose enhancement keeps this time scale finite in a condensate. Coherent transients are therefore absent in photoassociation of a thermal non-degenerate gas, but are feasible if the gas is a condensate.     

Gravure offset printing of polymer inks for conductors

A gravure offset printing process has been developed for Ag-filled polymer conductor ink. Pad printing and roller type printing have been used. Curing and electrical properties have been studied. A roller type of gravure offset printing has been used to evaluate the printing process and pad printing to print on the non-planar substrates. Based on differential scanning calorimetry (DSC) and resistivity measurements during ink curing, it was found that the ink had an optimum curing temperature of 140 °C. Square resistance of 300 and 150 μm wide lines can be as low as 20 and 28 mΩ/sq., respectively, for 7–8.5 μm thick line. The minimum line width was 70 μm. This minimum line width can be reduced with different ink solvents, but in this case the line thickness suffers and the square resistance increases, respectively.     

A framework for local and regional energy system integration between industry and municipalities—Case study UPM-Kymmene Kaukas

The integration of different energy systems, e.g., industrial and municipal, is potentially important for the efficient utilization of energy. It is important that the tools for analysing this type of integration can handle the energy systems on different levels, e.g., regional, site, plant and process levels. In this work, a framework for investigating the cost-efficient integration of large-scale energy systems is presented and tested at the UPM-Kymmene Kaukas pulp and paper plant and in the municipality of Lappeenranta, Finland. In addition to the different levels, the framework also aims to take into account several sub-problems, e.g., fuel logistic, optimal heat exchanger network and overall efficiency versus flexibility. The case in question shows that the presented framework can be used as a systematic tool for analysing the potential of integrating large energy systems and that it is able to handle both the synthesis of flexible heat exchanger networks and analyse the cost-efficiency of changes to the existing systems.     

Comparison of Two Integrated BiCMOS 950 MHz Direct I/Q Modulators

Two integrated direct I/Q modulators suitable for directupconversion with an output frequency of 950 MHz and baseband frequencies of60 to 500 kHz are fabricated in a 1.2 µm and 0.8 µm BiCMOSprocess, respectively, and their performance under various operatingconditions is discussed. The modulators use different phase shiftertopologies, one of which is based on digital CML latches and the other ondifferential pairs with resistive and capacitive emitter degeneration. Bothcircuits are operated using a single 5 V supply and they consume 50 mA or115 mA depending on the topology. The main properties of the CML modulatorare, for example, an output power of –11 ± 0.5 dBm at 100 MHzand –15 ± 2.25 dBm at 950 MHz over the temperature range of–10 to +85°C, LO suppression of 38 dBc and image rejection of41 dBc.