Hyperconjugated side chained benzodithiophene and 4,7-di-2-thienyl-2,1,3-benzothiadiazole based polymer for solar cells

A novel donor-acceptor (D-A) copolymer (P3TBDTDTBT), including hyperconjugated side chained benzodithiophene as a donor and 4,7-di-2-thienyl-2,1,3-benzothiadiazole (DTBT) as an acceptor, was designed and synthesized. Due to the introduction of the hyperconjugated side chain, the resultant polymer exhibited good thermal stability with a high decomposition temperature of 437 degrees C, a low band-gap of 1.67 eV with an absorption onset of 742 nm in the solid film, and a deep highest occupied molecular orbital (HOMO) energy level of -5.26 eV. Finally, the polymer solar cell (PSC) device based on this polymer and [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM) showed the best power conversion efficiency (PCE) of 3.57% with an open-circuit voltage (V-oc) of 0.78 V, a short-circuit current density (J(sc)) of 8.83 mA cm(-2) and a fill factor (FF) of 53%

Effect of heat extraction on water-soluble taste substances in processing products of chilled large yellow croaker (Pseudosciaena crocea)

In this paper, we analyzed the umami amino acids composition and content in minced meat (MM), fish head meat (HM), and fish roe (R). According to different ratios of material to liquid, we extracted water-soluble taste substances from the three materials and then compared composition and content of the umami amino acids and taste nucleotides in the different water-soluble taste substances. Finally, we analyzed Taste Activity Value (TAV) and the Equivalent Umami Concentration (EUC) between umami amino acids and taste nucleotides. The results showed that umami amino acids total content in MM, HM, and R samples were, respectively, 50.63 mg/100 g, 41.95 mg/100 g, and 67.06 mg/100 g. When the water-soluble taste substances extracted from the above samples were in the “D” state (MM), the “C” state (HM), and the “C” state (R), respectively, the umami amino acid content could be comparable to the original sample. And the highest EUCs were respectively 1.37 g MSG/100 g, 0.87 g MSG/100 g, and 0.49 g MSG/100 g (MSG: Sodium Glutamate). To some extent, the results of this study indicated that the water-soluble taste substances could be equivalent to the original sample and could be further applied as a taste regulator in some respects

Effects of Radio Frequency Tempering on the Texture of Frozen Tilapia Fillets

Radio frequency (RF) tempering has been proposed as a new alternative method for tempering frozen products because of its advantages of rapid and volumetric heating. In this study, the texture of RF-tempered frozen tilapia fillets was determined under different RF conditions, the effects of related factors on the texture were analyzed, and the mechanisms by which RF tempering affected the texture of the tempered fillets were evaluated. The results show that the springiness (from 0.84 mm to 0.79 mm), cohesiveness (from 0.64 mm to 0.57 mm), and resilience (from 0.33 mm to 0.25 mm) decreased as the electrode gap was increased and the power remained at 600 W, while the shear force increased as the power was increased for the 12 cm electrode gap (from 15.18 N to 16.98 N), and the myofibril fragmentation index (MFI) values were markedly higher at 600 W than at 300 W or 900 W (p < 0.05). In addition, the tempering uniformity had a positive effect on hardness and chewiness. The statistical analysis showed that the texture after RF tempering under different RF conditions correlated relatively strongly with the free water content, cooking loss, and migration of bound water to immobilized water. The decrease in free water and bound water migration to immobilized water resulted in a significant increase in cohesiveness and resilience

Effect of Storage Temperature and Time on Biogenic Amines in Canned Seafood

Biogenic amines in canned seafood are associated with food quality and human health. In this study, a total of nine biogenic amines (histamine (HIS), phenylethylamine (PHE), tyramine (TYM), putrescine (PUT), cadaverine (CAD), tryptamine (TRY), spermine (SPM), spermidine (SPD), and octopamine (OCT)) were used as standards. The biogenic amines of five canned seafood species (canned mud carp, canned sardine, canned mantis shrimp, canned scallop, and canned oyster) were investigated every three months for 12 months at different storage temperatures (4, 10, 25, and 30 °C). The biogenic amine contents were determined by the ultrasound-assisted dispersive solid-phase extraction method combined with reversed-phase high-performance liquid chromatography-photodiode array detection (UADSPE-RPLC-PDA). These results showed a detection rate of 100, 60, and 40% for HIS, PHE, PUT, and TYM; CAD, SPM, and SPD; OCT in all the samples, respectively. The contents of histamine and tyramine exceeded the recommended maximum limits (50 and 100 mg kg−1) in the canned mud carp and canned scallop when stored at 30 °C, indicating their potential health risks (p < 0.05). This result also indicates that low temperatures could inhibit the BAs content of canned seafood during storage. Overall, storage temperature and time can be used as the primary means to monitor and control the quality and safety of canned seafood

Synthesis and solar cells applications of EO-PF-DTBT polymer

Poly{[2,7-(9,9-bis-(1-(2-(2-methoxyethoxy)ethoxy)ethyl)-fluorene)]-alt-[5, 5-(4,7-di-2′-thienyl-2,1,3-benzothiadiazole)]} (EO-PF-DTBT) was synthesized by Suzuki coupling reaction. The polymer is soluble in common organic solvent, such as toluene, THF, and chloroform, and it also shows solubility in polar solvent, such as cyclopentanone. Solar cells based on EO-PF-DTBT and PC61BM show maximum power conversion efficiency of 2.65% with an open circuit voltage (VOC) of 0.86 V, a short circuit current density (JSC) of 6.10 mA/cm2, and a fill factor of 51% under AM 1.5G illumination at 100 mW/cm2, which is the best results for fluorene and 4,7-di-2-thienyl-2,1,3-benzothiadiazole copolymers and PC61BM blend. The 1,8-diiodooctane can work well to reduce the over-aggregated phase structure in polymer solar cells. Our results suggest that the introducing high hydrophilic side chain into conjugated polymer donor materials can tune the aggregation structure and improve the solar cells performances.</p