Characteristics of steam hydrogasification of wood using a micro-batch reactor

Hydrogasification of pinewood was studied in the presence of steam using a micro-batch reactor. A series of reaction experiments were performed at temperatures ranging from 873 to 1043 K, and pressures ranging from 5 to 35 bar. It was found that steam significantly increases not only the rate of the hydrogasification reaction but also the conversion of carbon into product gases. The enhancement of the formation of total carbon-containing gases (CH₄, CO, CO₂ and C₂+) by adding steam is estimated to be as high as 30 times greater compared to dry hydrogasification at 1043 K. Increased hydrogen pressure also enhanced methane formation in the product gas.     

Higher order eigenfields in mode II cracks under elastic-plastic deformation

The explicit formulation of theJ-integral and theM-integral is constructed in terms of the stress intensity factor and the higher order stress coefficients for Mode II cracks under small or large scale yielding. Furthermore, the stress intensity factor and the higher order stress coefficients as well are computed with the aid of the two-stateJ- and theM - integral, which is found to be accurate and efficient. It is found that the contribution from the higher order singularities to theJ - integral is closely related to the configuration of the plastic zone.     

Physical separation using an autogenous medium on coal

The dry beneficiation for 1–5 and 5–10-mm-size coal using an air table was investigated. Separation was conducted using autogenously formed media in the feed coal. The separation density was around 1.8–2.0 g/cm³ and the average Ep (Ecart Probability) value ranged from 0.08–0.1 for the 5–10-mm fraction, to around 0.1–0.12 for the 1–5-mm fraction. For the 5–10-mm fraction, the feed ash decreased from 44% to 8.4% in the clean coal product, with 89.5% ash rejection rate in the rejects. For the 1–5-mm fraction, the feed ash decreased from 33.7% to 9.4%, and the reject ash was 88.7%.     

Semi-transparent thin film solar cells by a solution process

Easily processed, low cost, and highly efficient solar cells are desirable for photovoltaic conversion of solar energy to electricity. We present the fabrication of precursor solution processed CuInGaS2 (CIGS) thin film solar cells on transparent indium tin oxide (ITO) substrates. The CIGS absorber film was prepared by a spin-coating method, followed by two successive heat treatment processes. The first annealing process was on a hot plate at 300 °C for 30 min in air to remove carbon impurities in the film; this was followed by a sulfurization process at 500 °C in an H₂S(1%)/Ar environment to form a polycrystalline CIGS film. The absorber film with an optical band-gap of 1.52 eV and a thickness of about 1.1 µm was successfully synthesized. Because of the usage of a transparent glass substrate, a bifacial CIGS thin film device could be achieved; its power conversion efficiency was measured to be 6.64% and 0.96% for front and rear illumination, respectively, under standard irradiation conditions.     

CuO formation control as a function of mixed ratio of Cu-free powders in the synthesis of YBCO superconductors on Cu substrates

YBa₂Cu₃O_x (Y123) superconducting films were fabricated on Cu substrates using a simple screen-printing method, from Cu-free powders (Y₂O₃ and BaCO₃). In the process, CuO, which causes superconducting properties of Y123 films to deteriorate, was formed on the film surface. By varying the atomic ratio of Y to Ba (Y:Ba = 1:1∼1:4), the ratio needed to prevent CuO formation was found for the film surface that had been heat-treated at 980^∘C for 17 s. The film, with the ratio of Y to Ba (Y:Ba = 1:1), is reheat-treated at 930^∘C for 9 min 30 s to form a superconducting Y123 phase. It was possible to prevent CuO formation by controlling the ratio of Cu-free powders in the mixture and to fabricate YBCO superconductors on Cu substrates using a two-step heat-treatment.     

Water extract of licorice (Glycyrrhiza uralensis Fisch.) Supplementation is related with decreased lipid peroxidation among healthy male smokers with glutathione-S-transferase M1 positive genotype

Recently, licorice (Glycyrrhiza uralensis Fisch., GU) has demonstrated significant in vitro and in vivo antioxidant properties. In this study, it was tested that a daily regimen of supplementation with water extract of GU would ameliorate oxidative stress and whether effects were modulated by the glutathion-S-transferase (GST) polymorphisms. Forty healthy male smokers aged 20–60 were divided evenly into 2 groups and given either 260 mL of GU extracted with hot water or 260 mL of oligosaccharide based placebo every day for 8 weeks without any change of usual food intake, and blood samples were drawn before and after the intervention. Eight weeks of GU supplementation significantly decreased plasma conjugated dienes (a maker for lipid peroxidation) in GSTM1 positive subjects, but not in the GSTM1 null genotype group. Our finding suggests that consumption of licorice water extract might be effectively decreasing lipid peroxidation in the subgroup of smokers who have GSTM1 gene.     

Efficiency improvement of polymer light-emitting diodes using a quantum dot interlayer between a hole transport layer and an emitting layer

The current efficiency of polymer light-emitting diodes (PLEDs) were improved using a quantum dot interlayer between a hole transport layer and an emitting layer. The quantum dot interlayer played a role of controlling the hole transport in the PLEDs and enhanced the charge balance in the emitting layer. The current efficiency of the PLEDs was increased by more than 20% by the quantum dot interlayer. In particular, the efficiency improvement was significant at high luminance due to reduced efficiency roll-off in the quantum dot-embedded PLEDs.     

Enhanced transformation of triclosan by laccase in the presence of redox mediators

Triclosan (TCS), an antimicrobial agent, is an emerging and persistent environmental pollutant that is often found as a contaminant in surface waters and sediments; hence, knowledge of its degradability is important. In this study we investigated laccase-mediated TCS transformation and detoxification, using laccase (from the fungus Ganoderma lucidum) in the presence and absence of redox mediators. Transformation products were identified using HPLC, ESI-MS and GC-MS, and transformation mechanisms were proposed. In the absence of redox mediator, 56.5% TCS removal was observed within 24 h, concomitant with formation of new products with molecular weights greater than that of TCS. These products were dimers and trimers of TCS, as confirmed by ESI-MS analysis. Among the various mediators tested, 1-hydroxybenzotriazole (HBT) and syringaldehyde (SYD) significantly enhanced TCS transformation (∼90%). The presence of these mediators resulted in products with lower molecular weights than TCS, including 2,4-dichlorophenol (2,4-DCP; confirmed by GC-MS) and dechlorinated forms of 2,4-DCP. When SYD was used as the mediator, dechlorination resulted in 2-chlorohydroquinone (2-CHQ). Bacterial growth inhibition studies revealed that laccase-mediated transformation of TCS effectively decreased its toxicity, with ultimate conversion to less toxic or nontoxic products. Our results confirmed the involvement of two mechanisms of laccase-catalyzed TCS removal: (i) oligomerization in the absence of redox mediators, and (ii) ether bond cleavage followed by dechlorination in the presence of redox mediators. These results suggest that laccase in combination with natural redox mediator systems may be a useful strategy for the detoxification and elimination of TCS from aqueous systems.     

Fast full‐color reflective display via photoluminescent enhancement

Reflective displays are advantageous in applications requiring low power or daylight readability. However, there are no low‐cost reflective technologies capable of displaying bright colors. By employing photoluminescence to more efficiently use ambient light, we created a prototype display that provides bright, full color in a simple, low‐cost architecture. This prototype includes a novel electrokinetic shutter, a layer that incorporates patterned luminescent red, green, and blue sub‐pixel elements, and a novel optical out‐coupling scheme. The luminescent elements convert otherwise‐wasted portions of the incident spectrum to light in the desired color band, resulting in improved color saturation and lightness. This prototype provides a color gamut that is superior to competing reflective display technologies that utilize color filters in single‐layer side‐by‐side sub‐pixel architectures. The current prototype is capable of switching in <0.5 s; future displays based on an alternative electro‐optic shutter technology should achieve video rate operation. A transflective version of this technology has also been prototyped. The transflective version utilizes its backlight with a power efficiency that is at least three times that of a conventional liquid crystal display. These photoluminescence‐based technologies enable a host of applications ranging from low‐power mobile products and retail pricing signage to daylight readable signage for outdoor advertising segments.     

Uncertain clustering algorithms based on rough and fuzzy sets for real-time image segmentation

In real pattern recognition applications, the complete and accurate information of a given set is not always easy to get. Such incomplete knowledge may lead to imperfect expressions of the set using many pattern recognition methods. Rough sets theory is designed to approximately describe an imprecise set by a pair of lower and upper approximations which are weighted by different parameters. As the distributive character varies from one set to another, it is undesirable to employ a constant weighted parameter for controlling the importance of the lower and upper approximations on describing various given sets. This paper presents an improved rough-fuzzy c-means clustering algorithm in which a parameter selection strategy is designed to adaptively adjust the weighted parameter depending on the distributive character of each cluster instead of manually choosing a constant parameter. Such an online-decision method enables the formed prototype to get close to the desirable location. Experimental results on synthetic datasets, real-life datasets, and image segmentation problems confirm the effectiveness of the proposed adaptive parameter selection strategy. With the introduction of adaptive parameter selection strategy, the improved rough sets-based clustering algorithm outperforms its counterparts in certain cases.