Hexagrid – hexagonal tube structures for tall buildings: patterns,modeling, and design

This paper provides a first insight on tube configurations based on the hexagonal shape (hexagrid) for tall buildings. The idea is to investigate the mechanical properties of hexagrid to assess their applicability in tall buildings and to compare their potential efficiency to the more popular diagrid systems. For the above purposes, a general homogenization approach has been established for dealing with any structural patterns, and a methodology for characterizing the structural patterns from the mechanical point of view has been developed and specified for hexagrids and diagrids. Then on the basis of a simple stiffness criterion, a design procedure has been proposed and applied to a tall building case study, and several structural solutions (both hexagrids and diagrids) have been designed and assessed by varying the major geometrical parameters of the patterns. Copyright © 2015 John Wiley & Sons, Ltd.     

Progress on large area n‐type silicon solar cells with front laser doping and a rear emitter

We report on the progress of imec's n‐type passivated emitter, rear totally diffused rear junction silicon solar cells. Selective laser doping has been introduced in the flow, allowing the implementation of a shallow diffused front surface field and a reduction of the recombination current in the contact area. Simplifications have been implemented towards a more industrial annealing sequence, by replacing expensive forming gas annealing steps with a belt furnace annealing. By applying these improvements, together with an advanced texturing process and emitter passivation by atomic layer deposition of Al₂O₃, 22.5% efficient cells (three busbars) have been realized on commercial 156 · 156 mm² Czochralski‐Si. This result has been independently confirmed by ISE CalLab. Copyright © 2016 John Wiley & Sons, Ltd.     

Degradation of pharmaceutical compound pentoxifylline in water by non-thermal plasma treatment

The decomposition of a model pharmaceutical compound, pentoxifylline, in aqueous solution was investigated using a dielectric barrier discharge (DBD) in coaxial configuration, operated in pulsed regime, at atmospheric pressure and room temperature. The solution was made to flow as a film over the surface of the inner electrode of the plasma reactor, so the discharge was generated at the gas-liquid interface. Oxygen was introduced with a flow rate of 600 sccm. After 60 min plasma treatment 92.5% removal of pentoxifylline was achieved and the corresponding decomposition yield was 16 g/kWh. It was found that pentoxifylline degradation depended on the initial concentration of the compound, being faster for lower concentrations. Faster decomposition of pentoxifylline could be also achieved by increasing the pulse repetition rate, and implicitly the power introduced in the discharge, however, this had little effect on the decomposition yield. The degradation products were investigated by liquid chromatography-mass spectrometry technique (LC-MS). The evolution of the intermediates during plasma treatment showed a fast increase in the first 30 min, followed by a slower decrease, so that these products are almost completely removed after 120 min treatment time.     

Polarity reversal induced by electrochemically generated thiazol-2-ylidenes: The Stetter reaction

The inversion of the normal reactivity (umpolung) of aldehydes has been induced via N-heterocyclic carbenes (NHCs) thiazol-2-ylidenes 2a or 3a, generated by simple electrolyses of solutions containing thiazolium salt 2 or 3. Accordingly, 1,4-dicarbonyl compounds have been obtained, in mild conditions and in moderate to very high yields, via 1,4-addition of the Breslow intermediates to the suitable Michael acceptor. The procedure has been performed in classical organic solvents (VOCs) as well as in room temperature ionic liquids (RTILs). The different reactivity of aliphatic aldehydes vs the one of aromatic and heteroaromatic aldehydes has been emphasized.     

Systematic synthesis of functional unsymmetric FeZn model complexes for plant purple acid phosphatases

The heterodinuclear complexes [FeZn(L)(CH₃CO₂)₂]⁺ (L = ICIMP or IPCPMP) are structural models for the dinuclear active sites of plant purple acid phosphatases. They can be systematically synthesized from mononuclear iron complexes and enhance the rate of transesterification of 2-hydroxypropyl p-nitrophenyl phosphate, an assay for the catalytic hydrolysis performed by purple acid phosphatases.     

Effect of coffee physical structure on volatile release

The mechanisms of volatile release from soluble coffee powders with different roasting degrees were studied. The presence of volatiles in the headspace during coffee humidification was analyzed by gas chromatography. Small amounts of volatiles were observed at low water activities (a_w), independently from the roasting degree; as the a_w increased headspace volatiles rose and then decreased as the moisture further increased. The changes in a_w and volatiles went along with the changes of coffee structure from a free-flowing powder to a sticky viscous fluid. The mechanism of volatiles release was controlled by both kinetic and thermodynamic factors. The former prevailed at low a_w in glassy systems; while the latter became important at high a_w when, due to increased mobility, equilibrium conditions were approached. Modified state diagrams were used to predict the critical temperature and a_w at which structural collapse and volatile release occurred. As far as equilibrium condition was achieved, coffee volatiles were partially re-adsorbed in the liquid phase.     

In vitro fermentation characteristics of diets with different forage/concentrate ratios: comparison of rumen and faecal inocula

BACKGROUND: The aim of this trial was to evaluate the replacement of rumen fluid with faeces as inoculum in studying the in vitro fermentation characteristics of diets for ruminants using the in vitro gas production technique. Six iso‐protein diets with different forage/concentrate ratios were incubated with rumen fluid (RI) or faeces (FI) collected from sheep. RESULTS: Most of the fermentation parameters were influenced by diet and inoculum (P < 0.01). With both inocula, organic matter degradability (dOM), cumulative gas production (OMCV) and maximum fermentation rate (R_max) increased as the amount of concentrate in the diet increased. R_max was lower with FI vs RI (P < 0.01); dOM was higher with FI vs RI and the diet × inoculum interaction was significant. As expected, with both inocula, R_max increased as the neutral detergent fibre content of the diet decreased. Significant correlations were obtained using both inocula between OMCV/dOM and gas/volatile fatty acid (VFA), while the correlation VFA/dOM was significant only with FI. The microbial biomass yield calculated by stoichiometric analysis for all diets was higher with FI vs RI. With FI the organic matter used for microbial growth showed an overall decreasing trend as the amount of concentrate in the diet increased. CONCLUSION: The results indicate that both faeces and rumen fluid from sheep have the potential to be used as inoculum for the in vitro gas production technique. Copyright © 2011 Society of Chemical Industry     

Recent developments in cold plasma-based enzyme activity (browning,cell wall degradation,and antioxidant) in fruits and vegetables

According to the Food and Agriculture Organization of United Nations reports, approximately half of the total harvested fruits and vegetables vanish before they reach the end consumer due to their perishable nature. Enzymatic browning is one of the most common problems faced by fruit and vegetable processing. The perishability of fruits and vegetables is contributed by the various browning enzymes (polyphenol oxidase, peroxidase, and phenylalanine ammonia-lyase) and ripening or cell wall degrading enzyme (pectin methyl-esterase). In contrast, antioxidant enzymes (superoxide dismutase and catalase) assist in reversing the damage caused by reactive oxygen species or free radicals. The cold plasma technique has emerged as a novel, economic, and environmentally friendly approach that reduces the expression of ripening and browning enzymes while increasing the activity of antioxidant enzymes; microorganisms are significantly inhibited, therefore improving the shelf life of fruits and vegetables. This review narrates the mechanism and principle involved in the use of cold plasma technique as a nonthermal agent and its application in impeding the activity of browning and ripening enzymes and increasing the expression of antioxidant enzymes for improving the shelf life and quality of fresh fruits and vegetables and preventing spoilage and pathogenic germs from growing. An overview of hurdles and sustainability advantages of cold plasma technology is presented.     

Exposure to fine and ultrafine particles from secondhand smoke in public places before and after the smoking ban, Italy 2005

Background

A smoking ban in all indoor public places was enforced in Italy on 10 January 2005.

Methods

We compared indoor air quality before and after the smoking ban by monitoring the indoor concentrations of fine (<2.5 μm diameter, PM_2.5) and ultrafine particulate matter (<0.1 μm diameter, UFP). PM_2.5 and ultrafine particles were measured in 40 public places (14 bars, six fast food restaurants, eight restaurants, six game rooms, six pubs) in Rome, before and after the introduction of the law banning smoking (after 3 and 12 months). Measurements were taken using real time particle monitors (DustTRAK Mod. 8520 TSI; Ultra‐fine Particles Counter‐TRAK Model 8525 TSI). The PM_2.5 data were scaled using a correction equation derived from a comparison with the reference method (gravimetric measurement). The study was completed by measuring urinary cotinine, and pre‐law and post‐law enforcement among non‐smoking employees at these establishments

Results

In the post‐law period, PM_2.5 decreased significantly from a mean concentration of 119.3 μg/m³ to 38.2 μg/m³ after 3 months (p<0.005), and then to 43.3 μg/m³ a year later (p<0.01). The UFP concentrations also decreased significantly from 76 956 particles/cm³ to 38 079 particles/cm³ (p<0.0001) and then to 51 692 particles/cm³ (p<0.01). Similarly, the concentration of urinary cotinine among non‐smoking workers decreased from 17.8 ng/ml to 5.5 ng/ml (p<0.0001) and then to 3.7 ng/ml (p<0.0001).

Conclusion

The application of the smoking ban led to a considerable reduction in the exposure to indoor fine and ultrafine particles in hospitality venues, confirmed by a contemporaneous reduction of urinary cotinine.     

Intracellular localization of dietary and naked DNA in intestinal tissue of Atlantic salmon, Salmo salar L. using in situ hybridization

There is a continuing interest in the fate of DNA from genetically modified organisms (GMO) in the food chain including the uptake of DNA by intestinal cells from dietary sources containing GM feed ingredients. The objective of this study was to elucidate the uptake and persistence of foreign DNA in the intestinal tract of Atlantic salmon Salmo salar L. using in situ hybridization (ISH) that enables the intracellular localization of the DNA, and polymerase chain reaction (PCR) to verify the ISH results qualitatively. Two salmon intestinal models were employed for the investigations; intestinal tissues were sampled in two models namely (a) in vivo from salmon-fed diets containing 30% GM soybeans or 30% nonGM (nGM) soybeans, and (b) ex vivo from intestinal sleeves incubated using different concentrations of PCR-amplified test DNAs (211 and 305 bp) designed from the 35S promoter/plant DNA junction of the RoundupReady soybean (RRS) genome. Additionally, for the incubation study, the effect of a mucolytic agent dithiothreitol (DTT) and a permeability enhancer sodium deoxycholate (SDA) on DNA uptake were investigated. Both treatments were found to enhance DNA uptake ex vivo. Dietary DNA and PCR-amplified DNA could be visualized by ISH in the salmon intestine with more frequently observed signals in the ex vivo model compared to the in vivo model. All results could be verified by PCR. Dietary DNA was localized in the cell vacuolar system and in lamina propria of the mid intestine. Thus, based on the investigated DNA fragment lengths, this study shows that foreign DNA, can be taken up by Atlantic salmon intestinal tissue.