1,130 research outputs found

    Enhancing 2D Growth of Organic Semiconductor Thin Films with Macroporous Structures via a Small-Molecule Heterointerface

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    The physical structure of an organic solid is strongly affected by the surface of the underlying substrate. Controlling this interface is an important issue to improve device performance in the organic electronics community. Here we report an approach that utilizes an organic heterointerface to improve the crystallinity and control the morphology of an organic thin film. Pentacene is used as an active layer above, and m-bis(triphenylsilyl) benzene is used as the bottom layer. Sequential evaporations of these materials result in extraordinary morphology with far fewer grain boundaries and myriad nanometre-sized pores. These peculiar structures are formed by difference in molecular interactions between the organic layers and the substrate surface. The pentacene film exhibits high mobility up to 6.3 cm(2)V(-1)s(-1), and the pore-rich structure improves the sensitivity of organic-transistor-based chemical sensors. Our approach opens a new way for the fabrication of nanostructured semiconducting layers towards high-performance organic electronics.X116049Nsciescopu

    Optimalne potrebe juvenilnih morskih grgeča sebastes schlegeli u proteinima i lipidima

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    U ovom istraživanju su analizirane optimalne potrebe juvenilnih morskih grgeča Sebastes schlegeli u proteinima i lipidima. 810 juvenilnih riba je izabrano po principu slučajnosti i distribuirano u 27 tankova od po 50 L sa protočnih sistemom. Pripremljeno je 9 eksperimentalnih smeša u vidu 3x3 faktorijalne eksperimentalne postavke: tri nivoa proteina (45, 50 i 55%) x tri nivoa lipida (11, 15 i 19%). Nivo proteina je imao uticaj na prirast riba, dok nivo lipida nije. Prirast riba hranjenih smešom u odnosu 50P-15L (50% proteina i 15% lipida) je bio veći nego prirast riba hranjenih smešama sa 45% proteina, bez obzira na nivo lipida, ali je bio isti kao kod riba hranjenih sa smešama 50P-11L, 50P-19L, 55P-11L, 55P-15L i 55P-19L. Stopa efikasnosti hrane (FER) riba je bila pod uticajem proteina u hrani ali ne i nivoa lipida. Stopa efikasnosti proteina (PER) riba je takođe bila pod uticajem proteina u hrani ali ne i nivoa lipida. Može se zaključiti da je za juvenilne Sebastes schlegeli optimalan nivo proteina i lipida za dobar prirast i iskoristljivost hrane (PER and NRE) 50% i 15% odnosno 45% i 19%, dok je optimalan odnos proteina i energije 27.4 i 23.9 mg protein/kJ

    The role of PET/CT for evaluating breast cancer

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    Positron emission tomography combined with computed tomography (PET/CT) has been receiving increasing attention during the recent years for making the diagnosis, for determining the staging and for the follow-up of various malignancies. The PET/CT findings of 58 breast cancer patients (age range: 34-79 years old, mean age: 50 years) were retrospectively compared with the PET or CT scans alone. PET/CT was found to be better than PET or CT alone for detecting small tumors or multiple metastases, for accurately localizing lymph node metastasis and for monitoring the response to chemotherapy in breast cancer patients

    Nanometer sized Ni-dot/Ag/Pt structure for high reflectance of p-type contact metal in InGaN light emitting diodes

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    The Ni-dot/Ag/Pt layer, where Ni-dot layer is formed of nanometer sized Ni dots, has been used to improve the reflectivity from the surface of p-type GaN in a light emitting diode (LED). Comparing with Ni/Ag/Pt layer, where Ni layer is a thin film, the Ni-dot/Ag/Pt structure shows significantly improved reflectivity with stable contact resistivity. The optical output power and external quantum efficiency of InGaN LEDs with Ni-dot/Ag/Pt structure for p-metal have improved by 28% and 29%, respectively, over the results of Ni/Ag/Pt structure

    Defect states in hybrid solar cells consisting of Sb2S3 quantum dots and TiO2 nanoparticles

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    We have studied defect states in an organic-inorganic hybrid solar cell containing Sb2S3 quantum dots (QDs) and TiO2 nanoparticles (NPs) by using deep level transient spectroscopy (DLTS). An Au electrode was deposited as a Schottky contact on the sample, where the Sb2S3 QDs were distributed on the surface of TiO2 NPs by chemical synthesis. The activation energy and capture-cross section of an interface state between the Sb2S3 QDs and the TiO2 NPs were found to be about 0.78 eV and 2.21 x 10(-9) cm(-2), respectively. Also, the densities of this interface trap under a measurement voltage of -1 V were approximately 2.5 x 10(17) cm(-3). Based on these results, the interface trap was positioned around E-c - 1.03 eV below the conduction band edge of Sb2S3 QD. Thus, the external quantum efficiency of the solar cell was affected because of its role as a recombination center for carriers generated from Sb2S3 QDs. (C) 2013 AIP Publishing LLCclos

    Surgical Treatment of Adult Degenerative Scoliosis

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    The rapid increase of elderly population has resulted in increased prevalence of adult scoliosis. Adult scoliosis is divided into adult idiopathic scoliosis and adult degenerative scoliosis. These two types of scoliosis vary in patient age, curve pattern and clinical symptoms, which necessitate different surgical indications and options. Back pain and deformity are major indications for surgery in adult idiopathic scoliosis, whereas radiating pain to the legs due to foraminal stenosis is what often requires surgery in adult degenerative scoliosis. When selecting a surgical method, major symptoms and underlying medical diseases should be carefully evaluated, not only to relieve symptoms but also to minimize postoperative complications. Surgical options for adult degenerative scoliosis include: decompression alone; decompression and limited short fusion; and decompression coupled with long fusion and correction of deformity. Decompression and limited short fusion can be applied to patients with a small Cobb's angle and normal sagittal imbalance. For those with a large Cobb's angle and positive sagittal imbalance, long fusion with correction of deformity is required. When long fusion is applied, a careful decision regarding the extent of fusion level should be made when selecting L5 or S1 as the distal fusion level and T10 or the thoracolumbar junction as the proximal fusion level. For the fusion extending to the sacrum, restoration of sagittal balance and rigid fixation with additional iliac screws should be considered. Any surgical procedures for adult degenerative scoliosis are known to have relatively high occurrences of complications; therefore, risks and benefits should be meticulously considered before selecting a surgical procedure

    Thermal analysis of bulk filled composite resin polymerization using various light curing modes according to the curing depth and approximation to the cavity wall

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    OBJECTIVE: The purpose of this study was to investigate the polymerization temperature of a bulk filled composite resin light-activated with various light curing modes using infrared thermography according to the curing depth and approximation to the cavity wall. MATERIAL AND METHODS: Composite resin (AeliteFlo, Bisco, Schaumburg, IL, USA) was inserted into a Class II cavity prepared in the Teflon blocks and was cured with a LED light curing unit (Dr's Light, GoodDoctors Co., Seoul, Korea) using various light curing modes for 20 s. Polymerization temperature was measured with an infrared thermographic camera (Thermovision 900 SW/TE, Agema Infra-red Systems AB, Danderyd, Sweden) for 40 s at measurement spots adjacent to the cavity wall and in the middle of the cavity from the surface to a 4 mm depth. Data were analyzed according to the light curing modes with one-way ANOVA, and according to curing depth and approximation to the cavity wall with two-way ANOVA. RESULTS: The peak polymerization temperature of the composite resin was not affected by the light curing modes. According to the curing depth, the peak polymerization temperature at the depth of 1 mm to 3 mm was significantly higher than that at the depth of 4 mm, and on the surface. The peak polymerization temperature of the spots in the middle of the cavity was higher than that measured in spots adjacent to the cavity wall. CONCLUSION: In the photopolymerization of the composite resin, the temperature was higher in the middle of the cavity compared to the outer surface or at the internal walls of the prepared cavity
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