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21.
《Organic Electronics》2014,15(1):299-305
A direct comparison of charge transport and electronic traps in representative polymer–fullerene blend, poly (3-hexylthiophene) (P3HT) and 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C61 (PCBM), is carried out in dark and illuminated conditions based on the measurements of temperature-dependent current–voltage characteristics. In dark condition, the charge transport presents a transition from Ohmic to trap-limited current. While the trap-filled space charge limited current is observed under illumination at the same applied bias. From evaluations of trap density and energy distribution by a differential method, it is reveal that the diverse charge transport in dark and illuminated conditions is mainly caused by the different trap states distribution, which strongly affects the space charges and the electrical field in P3HT: PCBM blends. 相似文献
22.
《International Journal of Hydrogen Energy》2022,47(3):1499-1515
Dark fermentation (DF) is a promising technology for biohydrogen production. Low efficiency of biohydrogen production is a bottleneck of the scale-up prospects for DF. Additives have been extensively studied to improve the biohydrogen production efficiency. Among of them, iron-based additives present a promising application potential due to their demonstrated significant enhancement of DF efficiency and among the low-cost bioactive agents. However, current reviews mainly examined the effects of nano-materials on DF and an in-depth analysis of enhancing mechanisms with addition of iron-based additives in DF is still lacking. To this end, this article comprehensively reviewed and evaluated the effects of iron-based additives on DF. Further, the potential mechanisms, including altering metabolic pathways, improving activities of microbes and enzymes, promoting electron delivery, and enriching hydrogen-producing bacteria, were discussed. Lastly, prospects and challenges of iron-based additives for subsequent research and large-scale application for DF were summarized. 相似文献
23.
Daniele Lettieri-BarbatoDebora Villaño Bram BeheydtFiorella Guadagni Isabel TroghMauro Serafini 《Food chemistry》2012,132(3):1305-1310
The association between in vitro antioxidant capacity of dark chocolates with different cocoa percentage and the in vivo response on antioxidant status was investigated. In a randomized crossover design, 15 healthy volunteer consumed 100 g of high antioxidants dark chocolate (HADC) or dark chocolate (DC). In vitro, HADC displayed a higher Total Antioxidant Capacity (TAC) than DC. In vivo, plasma TAC significantly peaked 2 h after ingestion of both chocolates. TAC levels went back to zero 5 h after DC ingestion whilst levels remained significantly higher for HADC. HADC induced a significantly higher urinary TAC in the 5-12 h interval time than DC. No change was detected in urinary excretion of F2-isoprostanes. Plasma thiols and triacylglycerol (TG) levels significantly increased for both chocolate with a peak at 2 h remaining significantly higher for DC after 5 h respect to HADC. Results provide evidence of a direct association between antioxidant content of chocolate and the extent of in vivo response on plasma antioxidant capacity. 相似文献
24.
Ciro Vasmara Massimo Pindo Diego Micheletti Rosa Marchetti 《International Journal of Hydrogen Energy》2018,43(18):8707-8717
This study addresses for the first time the influence of initial pH on the evolution of microbial consortia in dark fermentation of scotta permeate, using a high-throughput sequencing approach. Three fermentation phases could be detected: 1) a lag phase with no substantial differences in microbial composition at different initial pH values; 2) an exponential H2 production phase, accompanied by a general increase of Clostridium genus components and higher incidence of Trichococcus genus at neutral and alkaline pH; 3) a final stationary phase, characterized by a general increase of Bifidobacterium and Lactobacillus genera in all reactors. The initial pH value influenced the relative abundance of Trichococcus at 16–48 h of incubation. The metabolic activity of this genus increased the amount of metabolic precursors of H2 so that, when pH lowered to 5.4, clostridia in the reactors with initial alkaline pH become more active H2-producers than those in the others. 相似文献
25.
Tami Astie Ulhiza Noor Illi Mohamad Puad Azlin Suhaida Azmi 《International Journal of Hydrogen Energy》2018,43(49):22148-22158
Sago wastewater (SWW) causes pollution to the environment due to its high organic content. Annually, about 2.5 million tons of SWW is produced in Malaysia. In this study, the potential of SWW as a substrate for biohydrogen production by Enterobacter aerogenes (E. aerogenes) was evaluated. Response Surface Methodology (RSM) was employed to find the optimum conditions. From preliminary optimization, it was found that the most significant factors were yeast extract, temperature, and inoculum size. According to Face Centered Central Composite Design (FCCCD), the maximum hydrogen concentration and yield were 630.67 μmol/L and 7.42 mmol H2/mol glucose, respectively, which is obtained from the sample supplemented with 4.8 g/L yeast extract concentration, 5% inoculum, and incubated at the temperature of 31 °C. Cumulative hydrogen production curve fitted by the modified Gompertz equation suggested that Hmax, Rmax, and λ from this study were 15.10 mL, 2.18 mL/h, and 9.84 h, respectively. 相似文献
26.
The effects of N/C, P/C and Fe/C ratios on dark fermentative hydrogen gas production from activated carbon treated WPT hydrolysate were investigated using Box–Behnken statistical experiment design. N/C, P/C and Fe/C ratios were chosen as independent variables while the H2 yield and SHPR were set as the objective functions. H2 yield and SHPR functions were described by two quadratic model functions. The addition of a proper amount of N, P and Fe to the fermentation media was found to be essential to enhance the H2 production performance. Linear and interaction terms of N/C and Fe/C did have a significant effect on the H2 yield in the model function. However, the SHPR was significantly affected by the linear and interaction terms of N/C and P/C. The most convenient N/C, P/C and Fe/C ratios resulting maximum H2 yield (0.656 mol H2/mol glucose) and SHPR (241.64 mL H2/g biomass.h) were determined as 0.05, 0.09 and 0.003 (w/w), respectively. 相似文献
27.
Inline electron holography and VEELS for the measurement of strain in ternary and quaternary (In,Al,Ga)N alloyed thin films and its effect on bandgap energy
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J.M. MÁNUEL C.T. KOCH V.B. ÖZDÖL W. SIGLE P.A. VAN AKEN R. GARCÍA F.M. MORALES 《Journal of microscopy》2016,261(1):27-35
We present the use of (1) dark‐field inline electron holography for measuring the structural strain, and indirectly obtaining the composition, in a wurtzite, 4‐nm‐thick InAlGaN epilayer on a AlN/GaN/AlN/GaN multinano‐layer heterosystem, and (2) valence electron energy‐loss spectroscopy to study the bandgap value of five different, also hexagonal, 20–50‐nm‐thick InAlGaN layers. The measured strain values were almost identical to the ones obtained by other techniques for similarly grown materials. We found that the biaxial strain in the III‐N alloys lowers the bandgap energy as compared to the value calculated with different known expressions and bowing parameters for unstrained layers. By contrast, calculated and experimental values agreed in the case of lattice‐matched (almost unstrained) heterostructures. 相似文献
28.
研究了一种新型相关双采样CTIA结构的焦平面读出电路,该电路采用光学调制器产生的信号来控制MOS管轮流导通,通过积分电容充放电,实现光电流转化为电压的过程。基于CSMC0.6μm DPDM CMOS工艺的BSIM 3V3 spice模型,采用Spectre对电路进行了仿真验证。在5V工作电源下,该读出方式在强背景应用中,不仅能有效地增加图像的动态范围和信噪比,而且也能提高输出电压摆幅、减小电路输出噪声。 相似文献
29.
Ya-Chieh Li Chen-Yeon Chu Shu-Yii Wu Chia-Ying Tsai Chia-Chi Wang Chun-Hsiung Hung Chiu-Yu Lin 《International Journal of Hydrogen Energy》2012
In this study, the yield of hydrogen production was investigated under different feedstock pretreatment conditions. The feedstock for dark fermentative hydrogen production was textile wastewater which was obtained from the de-sizing process in a textile factory, located in northern Taiwan. The wastewater was pretreated with activated carbon, cation exchange resin or was not pretreated before being fed into the batch bottles. Biohydrogen production was carried out in a batch reactor with the sludge of mixed-culture using the feedstock from the pretreated wastewater. The sludge was obtained from the Taichung municipal wastewater treatment plant. The yield of hydrogen production using the two pretreatment methods or non – treatment were compared. 相似文献
30.
We studied the influence of initial pH on hydrogen (H2) production using permeate from scotta (a partially deproteinized cheese whey from ricotta production) as substrate (51 g L?1 lactose). Dark fermentation was carried out at 35 °C in laboratory batch reactors, in an unbuffered system. Hydrogen production and metabolite (volatile fatty acids, ethanol, and lactic acid) evolution during a 96-h period were monitored in reactors with initial pH varying in the range 4–10. In all reactors, H2 production started only when pH fell below 6. However, it was much higher (+31%) in the reactors with initial alkaline pH. We conclude that H2 production occurs only at acidic pH values, but initial alkaline pH values increase the overall H2 production in dark fermentation of lactose-rich substrates. 相似文献