Local dimming light‐guiding plate type backlight system using alignment‐controlled polymer‐dispersed liquid crystals

A new technology which enables a local brightness control according to the displayed images has been expected in the thin and lightweight backlight systems to improve a contrast ratio and power consumption of the liquid crystal displays (LCDs). In this paper, we have proposed a novel local‐dimming backlight system using alignment‐controlled polymer‐dispersed liquid crystals as a light‐guiding plate and investigated the forming conditions of polymer‐dispersed liquid crystals to achieve both a high‐luminance ratio and a fast response speed. As a result, we found that a luminance ratio and response speed of the backlight system can be improved by using bifunctional LC monomer materials and forming fine and rigid polymer network in the LCs, and achieved high luminance ratio of 16:1 and fast response time less than 0.5 ms. In addition, we fabricated the twisted nematic‐mode LCD using the local dimming light‐guiding plate‐type backlight based on this design, and successfully realized eight times higher contrast ratio than that of the traditional twisted nematic‐mode LCD.     

Survival of Salmonella Enteritidis PT 30 on inoculated almond kernels in hot water treatments

Almonds are blanched by exposure to hot water or steam-injected water to remove the pellicle (skin) from the kernel. This study evaluated the survival of Salmonella Enteritidis PT 30, Salmonella Senftenberg 775W and Enterococcus faecalis on whole raw almond kernels exposed to hot water. Whole, inoculated (7 to 9 log CFU/g) Nonpareil almonds (40 g) were submerged in 25 L of water maintained at 60, 70, 80 and 88 °C. Almonds were heated for up to 12 min, drained for 2 s, and transferred to 80 mL of cold (4 °C) tryptic soy broth. Almonds in broth were stomached at high speed for 2 min, serially diluted, plated onto tryptic soy and bismuth sulfite agars (Salmonella) or bile esculin agar (Enterococcus) and incubated at 37 °C for 24 and 48 h, respectively. D values of 2.6, 1.2, 0.75 and 0.39 min were calculated for exposure of S. Enteritidis PT 30 to water at 60, 70, 80 and 88 °C, respectively; the calculated z value was 35 C°. D values determined for Salmonella Senftenberg 775W and E. faecalis at 88 °C were 0.37 and 0.36 min, respectively. Neither Salmonella serovar could be recovered by enrichment of 1-g samples after almonds inoculated at 5 log CFU/g were heated at 88 °C for 2 min. These data will be useful to validate almond industry blanching processes.     

Wind Force Coefficients for Designing Porous Canopy Roofs

Wind force coefficients for designing porous canopy roofs have been investigated based on a series of wind tunnel experiments. Gable, troughed and mono-sloped roofs were tested. The roof models were made of 0.5 mm thick perforated duralumin plates, the porosity of which was changed from 0 to about 0.4. Overall aerodynamic forces and moments acting on the roof model were measured in a turbulent boundary layer with a six-component force balance for various wind directions. The results indicate that the wind loads on canopy roofs generally decrease with an increase in porosity of the roof. Assuming that the roof is rigid and supported by the four corner columns with no walls, the axial forces induced in the columns are regarded as the most important load effect for discussing the design wind loads. Two loading patterns causing the maximum tension and compression in the columns are considered. Based on a combination of the lift and moment coefficients, the design wind force coefficients on the windward and leeward halves of the roof are presented for the two loading patterns as a function of the roof pitch and porosity. The effect of porosity is taken into account as a reduction factor of the wind loads.     

The Reaction of Alkynes with Model Gold Catalysts: Generation of Acetylides,Self-coupling and Surface Decomposition

Catalysis Letters - Alkynes are one of the most important groups of building blocks in organic chemistry as they work as nucleophiles upon deprotonation of its acidic hydrogen. On the surface of a...     

Spectroscopic studies of triboluminescence from a sliding contact between diamond, SiO2, MgO, NaCl, and Al2O3 (0001)

We have measured spectra of the light emission from the frictional contact between the pin of natural diamond, synthetic fused silica, MgO, or NaCl and the disk of quartz or synthetic sapphire in a vacuum in the wavelength range between 380 and 1000 nm. Each spectrum shows the relaxation of electronic excited vacancies, which are thought to be produced at the solid surface by mechanical abrasion.     

Observation of non-chemical equilibrium effect on Ar-CO2-H2 thermal plasma model by changing pressure

The authors developed a two-dimensional one-temperature chemical non-equilibrium (1T-NCE) model of Ar-CO₂-H₂ inductively coupled thermal plasmas (ICTP) to investigate the effect of pressure variation. The basic concept of one-temperature model is the assumption and treatment of the same energy conservation equation for electrons and heavy particles. The energy conservation equations consider reaction heat effects and energy transfer among the species produced as well as enthalpy flow resulting from diffusion. Assuming twenty two (22) different particles in this model and by solving mass conservation equations for each particle, considering diffusion, convection and net production terms resulting from hundred and ninety eight (198) chemical reactions, chemical non-equilibrium effects were taken into account. Transport and thermodynamic properties of Ar-CO₂-H₂ thermal plasmas were self-consistently calculated using the first-order approximation of the Chapman-Enskog method. Finally results obtained at atmospheric pressure (760 Torr) and at reduced pressure (500, 300 Torr) were compared with results from one-temperature chemical equilibrium (1T-CE) model. And of course, this comparison supported discussion of chemical non-equilibrium effects in the inductively coupled thermal plasmas (ICTP).     

Synthesis of sulfonated organic–inorganic hybrids through the radical copolymerization of vinyl sulfonate esters and vinyl trialkoxysilanes

Novel organic–inorganic hybrids with sulfonic acid groups were prepared using random copolymers composed of vinyl sulfonate esters and vinyl trialkoxysilanes. Five vinyl sulfonate esters with different substituent groups were employed as protecting monomers for the production of the poly(vinyl sulfonic acid) component, and three vinyl trialkoxysilanes were used as cross-linkable monomers. Free radical and reversible addition-fragmentation chain transfer (RAFT) copolymerizations were performed for the production of random copolymers with two different functional groups. The selective deprotection of the sulfonate esters of the copolymers proceeded smoothly and resulted in the formation of copolymers with lithium vinyl sulfonate units and cross-linkable trialkoxysilane units. The co-condensation of the trialkoxysilane moieties in the deprotected copolymers with cross-linkers yielded transparent hybrid films that contained lithium sulfonate groups without aromatic rings or ester linkages.