CW-diode laser crystallization of sputtered amorphous silicon on glass, SiNx, and SiO2 intermediate layers

CW-diode laser crystallization of amorphous silicon (a-Si) deposited by sputtering or by electron beam evaporation onto different substrates (glass without or with SiN_x or SiO₂ intermediate layers) is investigated. The resulting grain sizes and orientations are characterized by electron backscatter diffraction, optical microscopy, and x-ray diffraction. We demonstrate that 200 nm thick sputtered a-Si layers can be crystallized on all of the used substrates to result in grains from 1 up to 100 μm in size, depending on the laser irradiation parameters (intensity, exposure time). Electron beam evaporated a-Si films can be crystallized only on sputtered SiN_x intermediate layers to result in grains of 100 μm in size. Similar crystallographic film properties follow from laser treatment if the product of laser peak intensity and square root of exposure time is kept constant, independent of the scan velocity used. A high fraction of preferred (100)-oriented silicon grains can only be observed for samples with crystallites less than 10 μm in size.     

Characterisation of CO/NO/SO2 emission and ash-forming elements from the combustion and pyrolysis process

Bioenergy is considered as a sustainable energy which can play a significant role in the future’s energy scenarios to replace fossil fuels, not only in the heat production, but also in the electricity and transportation sectors. Emission formation and release of main ash-forming elements during thermal conversion of biomass fuels at different conditions have been the scope of this study. The experiments were conducted in a quartz glass reactor where the temperature and atmosphere could be controlled. The selected fuels represent a wide range of biomass compositions. They are torrefied softwood, spruce bark, waste wood, miscanthus, and wheat straw. The fuels were first grinded and then pressed with a pellet maker into pellets of the same size and weight. For each fuel, the experiments were carried out under both oxidation and pyrolysis condition, with atmosphere of 3 % O₂ + 97 % N₂ and 100 % N₂, respectively, at four residence times. The selected temperatures under which experiments were performed are 800, 900, and 1,050 °C. The concentration of SO₂, NO, CO, and CO₂ emissions and O₂ were monitored online by three analysers, simultaneously. The residue weight was measured after each process, and the comparison with the ash content of the fresh pellet is made. Additionally, the release of several ash-forming elements (K, Zn, Na, and Mn) from the fuels has been quantified as function of temperature and residence time by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Time-dependent formation of NO and SO₂ and other emissions is presented and discussed with respect to different temperature and combustion conditions.     

Solubilisation of calcium and magnesium from the marine red algae Lithothamnion calcareum

Marine minerals are a potential source of calcium and magnesium for nutritional supplementation. This study analysed the solubilisation of calcium and magnesium from the skeletal remains of Lithothamnion calcareum. Scanning electron microscopy analysis demonstrated a nonporous microstructure. Spectrophotometric determination showed that the calcium and magnesium contents were 30.01 and 6.22% (w/w), respectively. Solubilisation of calcium and magnesium was highly pH dependent. The temperature‐dependent solubilisation of calcium fitted the shrinking core model. The apparent activation energy for calcium solubilisation was 28.6 kJ mol^?1. Inclusion of caseinophosphopeptides (CPPs), casein‐derived mineral binding peptides, during the solubilisation of calcium and magnesium appeared to decrease the extent of calcium solubilisation at pH 6.0 and 8.0. The results herein have implications for the choice of optimal pH conditions for the sustained release of calcium and magnesium from marine mineral sources.     

Adaptive controller placement for wireless sensor–actuator networks with erasure channels

Wireless sensor–actuator networks offer flexibility for control design. One novel element which may arise in networks with multiple nodes is that the role of some nodes does not need to be fixed. In particular, there is no need to pre-allocate which nodes assume controller functions and which ones merely relay data. We present a flexible architecture for networked control using multiple nodes connected in series over analog erasure channels without acknowledgments. The control architecture proposed adapts to changes in network conditions, by allowing the role played by individual nodes to depend upon transmission outcomes. We adopt stochastic models for transmission outcomes and characterize the distribution of controller location and the covariance of system states. Simulation results illustrate that the proposed architecture has the potential to give better performance than limiting control calculations to be carried out at a fixed node.     

Broccoli leaf powder as an attractive by-product ingredient: effect on batter behaviour,technological properties and sensory quality of gluten-free mini sponge cake

Broccoli by-products, in particular leaves, are rich sources of nutritional and bioactive components thus could constitute a valuable food additive. Although an upsurge in quantity of gluten-free products is observed further studies are required on improvement of their nutritional quality and palatability. This study aimed to investigate the influence of broccoli leaf powder (BLP) on dough behaviour, and technological characteristics and sensory quality of gluten-free mini sponge cake (GFS). Broccoli leaf powder replaced an equivalent amount (2.5%, 5%, 7.5%; w/w) of corn and potato starches in GFS formulation. Applied BLP increased the instrumental firmness of GFS but sensorial attributes (elasticity, crustiness, mastication and adhesiveness) were similar to the control. All broccoli GFS were vividly green, had small size pores properly distributed. Among them, sample with 2.5% BLP was distinguished for its desirable sensory quality, despite a slightly perceived cabbage aroma and taste. Moderate amount of BLP allows to preserve a good quality GFS improving its attractiveness and palatability.     

Investigation of the Equivalence of National Dew-Point Temperature Realizations in the ?50?°C to +?20?°C Range

In the field of humidity quantities, the first CIPM key comparison, CCT-K6 is at its end. The corresponding European regional key comparison, EUROMET.T-K6, was completed in early 2008, about 4?years after the starting initial measurements in the project. In total, 24 NMIs from different countries took part in the comparison. This number includes 22 EURAMET countries, and Russia and South Africa. The comparison covered the dew-point temperature range from ?50?°C to +20?°C. It was carried out in three parallel loops, each with two chilled mirror hygrometers as transfer standards in each loop. The comparison scheme was designed to ensure high quality results with evenly spread workload for the participants. It is shown that the standard uncertainty due to the long-term instability was smaller than 0.008?°C in all loops. The standard uncertainties due to links between the loops were found to be smaller than 0.025?°C at ?50?°C and 0.010?°C elsewhere. Conclusions on the equivalence of the dew-point temperature standards are drawn on the basis of calculated bilateral degrees of equivalence and deviations from the EURAMET comparison reference values (ERV). Taking into account 16 different primary dew-point realizations and 8 secondary realizations, the results demonstrate the equivalence of a large number of laboratories at an uncertainty level that is better than achieved in other multilateral comparisons so far in the humidity field.     

Failure of Titanium Condenser Tubes After 24 Years Power Plant Service

The titanium condenser has been in operation for 24 years at Amager unit 3 power plant. In February 2012, the plant was contaminated by seawater due to a failed condenser tube and some tubes were plugged. A month later, the plant tripped again. Small leaks were found again and finally approx. 200 tubes were plugged before the condenser was in service again. A series of inspections, NDT, and destructive examinations were conducted to try and understand the cause of failure in the tubes within the condenser. After such investigations, degradation mechanisms such as inner fouling, steam impingement, and fretting/erosion around the supports could be discounted. Ductile cracks were found in the tube within the tubesheet. From circumstantial evidence, it was concluded that failure was caused by a semi-filled condenser which led to a mismatch in expansion coefficients of filled tubes and unfilled tubes during a plant trip. In addition, small amounts of titanium hydride were revealed to be present in the tubes within the tubesheet indicating that the carbon steel tubesheet was corroding due to ingress of salt water. Although this was not the reason for the failure, it indicated the need for repair of the epoxy coating in the waterbox.     

A Symmetrical Diester as the Sex Attractant Pheromone of the North American Click Beetle Parallelostethus attenuatus (Say) (Coleoptera: Elateridae)

Hexanoic acid, 1-octanol, 1,8-octanediol, octyl hexanoate, 1,8-octanediol monohexanoate, and 1,8-octanediol dihexanoate were identified in headspace volatiles collected from the crushed abdomen of a female click beetle of the species Parallelostethus attenuatus (Say) (Elaterinae, tribe Elaterini). In field trials carried out in Illinois, South Carolina, North Carolina, and Virginia, adult male beetles were strongly attracted to 1,8-octanediol dihexanoate alone. Blends of the dihexanoate with one or more of the other compounds proved to be less attractive than the dihexanoate alone, suggesting that the pheromone of this species may consist of a single compound. The symmetrical diester structure of the pheromone is a novel natural product and appears to be structurally unique among insect pheromones.

     

A Danish case: portfolio evaluation and its impact on energy efficiency policy

A political agreement from 2005 stated that an evaluation of the entire Danish energy efficiency policy portfolio must be carried out before the end of 2008, with the aim to assess the following: (1) Is the policy portfolio sufficient to meet the energy efficiency targets? (2) Do the policies enable the national goals to be met in a cost-effective manner? (3) Is the overall design of the policy portfolio appropriate? The evaluation gave recommendations on how to improve and develop the portfolio, mainly using cost-effectiveness as criteria. The evaluation was completed in December 2008, and this paper presents the main findings and the subsequent impact on Danish policy. A key lesson learned is the importance of including all energy efficiency policies in the evaluation. Examining the entire portfolio of policies (as opposed to only selected policies) gave way to findings that would otherwise not have been captured. With its broad perspective, the evaluation found that the policy instruments prioritised the commercial and industrial sectors less than the household and public sectors. The recommendations made by the authors contributed to the implementation of new taxes for the commercial and industrial sectors together with the reform of the Electricity Saving Trust to a Centre for Energy Savings charged with energy savings within all sectors, except transport—both which have been important steps towards a more cost-effective solution.