Enhancing spectral contrast in organic red-light photodetectors based on a light-absorbing and exciton-blocking layered system

This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in JOURNAL OF APPLIED PHYSICS. 108(3):034502 (2010) and may be found at https://doi.org/10.1063/1.3466766 .We demonstrated a highly sensitive red-light photodetector based on a mixed copper phthalocyanine (CuPc) and fullerene C-60 photoactive layer, similar to a so-called bulk heterojunction structure usually used in the field of organic photovoltaics. We incorporated an additional set of organic layers that was composed of two organic p-type semiconductors to reduce the blue-light sensitivities of CuPc- and C-60-based organic photodetectors. We used alpha, omega-diphenyl sexi-thiophene (P6T) and alpha, omega-bis(biphenyl-4-yl)ter-thiophene (BP3T), which are thiophene-based materials and usually have good hole-transporting properties. A thick (>100 nm) P6T layer absorbed blue light, preventing it from reaching the photoactive layer, and a thin (similar to 20 nm) BP3T layer whose band gap was larger than that of P6T blocked excitation energy transfer from P6T to CuPc. Thus, we successfully demonstrated a red-light photodetector with high peak sensitivity and whose current-voltage characteristics did not worsen. The optimal device showed a peak incident photon-current conversion efficiency of 51.7% at 620 nm and a specific detectivity of 4.0 X 10(11) cm Hz(1/2)/W.ArticleJOURNAL OF APPLIED PHYSICS. 108(3):034502 (2010)journal articl

Physical properties of transparent perovskite oxides (Ba,La)SnO3 with high electrical mobility at room temperature

Transparent electronic materials are increasingly in demand for a variety of optoelectronic applications. BaSnO3 is a semiconducting oxide with a large band gap of more than 3.1 eV. Recently, we discovered that La doped BaSnO3 exhibits unusually high electrical mobility of 320 cm^2(Vs)^-1 at room temperature and superior thermal stability at high temperatures [H. J. Kim et al. Appl. Phys. Express. 5, 061102 (2012)]. Following that work, we report various physical properties of (Ba,La)SnO3 single crystals and films including temperature-dependent transport and phonon properties, optical properties and first-principles calculations. We find that almost doping-independent mobility of 200-300 cm^2(Vs)^-1 is realized in the single crystals in a broad doping range from 1.0x10^19 to 4.0x10^20 cm^-3. Moreover, the conductivity of ~10^4 ohm^-1cm^-1 reached at the latter carrier density is comparable to the highest value. We attribute the high mobility to several physical properties of (Ba,La)SnO3: a small effective mass coming from the ideal Sn-O-Sn bonding, small disorder effects due to the doping away from the SnO2 conduction channel, and reduced carrier scattering due to the high dielectric constant. The observation of a reduced mobility of ~70 cm^2(Vs)^-1 in the film is mainly attributed to additional carrier-scatterings which are presumably created by the lattice mismatch between the substrate SrTiO3 and (Ba,La)SnO3. The main optical gap of (Ba,La)SnO3 single crystals remained at about 3.33 eV and the in-gap states only slightly increased, thus maintaining optical transparency in the visible region. Based on these, we suggest that the doped BaSnO3 system holds great potential for realizing all perovskite-based, transparent high-frequency high-power functional devices as well as highly mobile two-dimensional electron gas via interface control of heterostructured films.Comment: 31 pages, 7 figure

Journal of the Korean Society of Marine Engineering 672 / 한국마린엔지니어링학회지 제33권 제5호

Abstract：Acoustic Emission (AE) technique is a non-destructive testing method and widely used for the early detection of faults in rotating machines in these days, because the sensitivity of AE transducers is higher than normal accelerometers. So it can detect low energy vibration signals. The faults in the rotating machines are generally occurred at bearings and gearboxes which are the principal parts of the machines. It was studied to detect the bearing faults by envelop analysis in several decade years. And the researches showed that AE had a possibility of the application in condition monitoring system(CMS) using the envelope analysis for the rolling bearing. And peak ratio (PR) was developed for expression of the bearing condition in condition monitoring system using AE. Noise level is needed to reduce to take exact PR value because the PR is calculated from total root mean square (RMS) and the harmonics peak levels of the defect frequencies of the bearing. Therefore, in this paper, the discrete wavelet transform (DWT) was added in the envelope analysis to reduce the noise level in the AE signals. And then, the PR was calculated and compared with general envelope analysis result and the result of envelope analysis added the DWT. In the experiment result about inner fault of bearing, defect frequency was difficult to find about only envelop analysis. But it's easy to find defect frequency after wavelet transform. Therefore, Envelop analysis added wavelet transform was useful method for early detection of default in signal process. Key words：Acousti

The ancient phosphatidylinositol 3-kinase signaling system is a master regulator of energy and carbon metabolism in algae

Algae undergo a complete metabolic transformation under stress by arresting cell growth, inducing autophagy and hyperaccumulating biofuel precursors such as triacylglycerols and starch. However, the regulatory mechanisms behind this stress-induced transformation are still unclear. Here, we use biochemical, mutational, and “omics” approaches to demonstrate that PI3K signaling mediates the homeostasis of energy molecules and influences carbon metabolism in algae. In Chlamydomonas reinhardtii, the inhibition and knockdown (KD) of algal class III PI3K led to significantly decreased cell growth, altered cell morphology, and higher lipid and starch contents. Lipid profiling of wild-type and PI3K KD lines showed significantly reduced membrane lipid breakdown under nitrogen starvation (-N) in the KD. RNA-seq and network analyses showed that under -N conditions, the KD line carried out lipogenesis rather than lipid hydrolysis by initiating de novo fatty acid biosynthesis, which was supported by tricarboxylic acid cycle down-regulation and via acetyl-CoA synthesis from glycolysis. Remarkably, autophagic responses did not have primacy over inositide signaling in algae, unlike in mammals and vascular plants. The mutant displayed a fundamental shift in intracellular energy flux, analogous to that in tumor cells. The high free fatty acid levels and reduced mitochondrial ATP generation led to decreased cell viability. These results indicate that the PI3K signal transduction pathway is the metabolic gatekeeper restraining biofuel yields, thus maintaining fitness and viability under stress in algae. This study demonstrates the existence of homeostasis between starch and lipid synthesis controlled by lipid signaling in algae and expands our understanding of such processes, with biotechnological and evolutionary implications.Ministry of Science, ICT and Future Planning 2015M3A6A2065697Ministry of Oceans and Fisheries 2015018

Coupling characteristics of surface modes in truncated two-dimensional photonic crystals

On 1 February, 1994 the Republic of Austria concluded the Accession Treaty and on 1 January, 1995 became a full member of the European Union. Membership obliged Austrians to ‘provide’ the Community with appropriate personnel to take up different posts in various EU authorities, as well as in the European Parliament. The most important issue was to alter particular statutory regulations and the Austrian Constitution to adjust to the new situation.The paper aims at presenting the Austrian solutions in this matter in the context of European Union law, with particular emphasis on regulations which are uncommon or specific to the Republic of Austria. The matter of interest is the constitutional practice of EU member states and the reader’s perspective is taken into account. The latter approach not only evaluates the Austrian solutions in the context of the electoral law to the European Parliament contained in the Election Code, but could also suggest some ideas in regard to prospective amendments. The authors would, in particular, like to pay attention to two issues: the lowering of the voting age, and the single constituency electoral system. The Austrian solutions might be valuable to refer to in the countries where a system of correspondence voting is just being introduced. These resolutions are particularly interesting taking into consideration prospective, possible amendments to the electoral laws of the EU member states.Republika Austrii, 1 lutego 1994 r. podpisała traktat akcesyjny i z dniem 1 stycznia 1995 r. stała się pełnoprawnym członkiem Unii Europejskiej. Członkostwo zobowiązało Austriaków do “dostarczenia” Wspólnocie odpowiednich osób do objęcia różnych stanowisk w różnych unijnych organach. Nie inaczej było także w przypadku Parlamentu Europejskiego. Ważnym aspektem stało się dostosowanie poszczególnych norm ustawowych i własnej konstytucji do nowych rozwiązań. Celem niniejszego opracowania jest właśnie przedstawianie austriackich rozwiązań w tym temacie na tle rozwiązań europejskich, ze szczególnym uwzględnieniem unormowań rzadko spotykanych lub wręcz odrębności sytemu Republiki Austrii. Rzecz wydaje się być interesująca zarówno z punktu widzenia praktyki ustrojowej państw członkowskich Unii Europejskiej, jak i z punktu widzenia czytelnika. To drugie podejście pozwoli na ocenę austriackich rozwiązań na tle niedawno wprowadzonej ordynacji wyborczej do PE zawartej w Kodeksie Wyborczym, ale również może podsunąć pewne pomysły, co do przyszłych nowelizacji. Autorzy zwrócili szczególną uwagę na dwa rozwiązania: obniżenie cenzusu wieku czynnego prawa wyborczego oraz jednookręgowy system wyborczy. Austriackie doświadczenia mogą być również pomocne państwom, które wprowadzają możliwość głosowania korespondencyjnego. Są to propozycje szczególnie interesujące z punktu widzenia przyszłych, możliwych nowelizacji systemów wyborczych państw członkowskich

Combined Analysis of the Time-Resolved Transcriptome and Proteome of Plant Pathogen Xanthomonas oryzae pv. oryzae

Xanthomonas oryzae pv. oryzae (Xoo) is a plant pathogen responsible for causing bacterial blight in rice. The immediate alterations in Xoo upon initial contact with rice are essential for pathogenesis. We studied time-resolved genome-wide gene expression in pathogenicity-activated Xoo cells at the transcriptome and proteome levels. The early response genes of Xoo include genes related to cell motility, inorganic ion transport, and effectors. The alteration of gene expression is initiated as early as few minutes after the initial interaction and changes with time. The time-resolved comparison of the transcriptome and proteome shows the differences between transcriptional and translational expression peaks in many genes, although the overall expression pattern of mRNAs and proteins is conserved. The discrepancy suggests an important role of translational regulation in Xoo at the early stages of pathogenesis. The gene expression analysis using time-resolved transcriptome and proteome provides unprecedented valuable information regarding Xoo pathogenesis

Clinical Review of Endogenous Endophthalmitis in Korea: A 14-Year Review of Culture Positive Cases of Two Large Hospitals

PURPOSE: To identify the clinical features and outcomes of endogenous endophthalmitis in Korea. MATERIALS AND METHODS: We reviewed 18 patients with endogenous endophthalmitis at 2 Korean hospitals, treated over a 14 year period between January 1993 and December 2006. RESULTS: The comorbidities observed in these cases were diabetes mellitus and liver cirrhosis. The most common pathogens, which were found in 7 patients each (38.9%), were Klebsiella pneumonia and Pseudomonas aeruginosa. All patients were treated with systemic antibiotics and fortified topical antibiotics. A surgical approach including vitrectomy was performed in 9 cases (50.0%). The prognosis was generally poor, and visual acuity improved slightly in 6 patients (33.3%). CONCLUSION: In this study, diabetes mellitus and Klebsiella pneumonia showed a close relationship with endogenous endophthalmitis, respectively. Endogenous endophthalmitis is a serious risk to sight and careful attention to establishing the diagnosis and management may decrease the ocular morbidity.ope