ZnO:B back reflector with high haze and low absorption enhanced triple-junction thin film Si solar modules

AbstractWe present our development of a ZnO:B back reflector (BR) with high haze and low absorption for highly efficient triple-junction thin film Si solar modules over a large area (1.1×1.3m2). We try to maximize light trapping by the evaluation of the use of transparent conducting oxide (TCO) and BR for high efficiency. It was verified that the configuration of SnO2:F front TCO and ZnO:B BR shows better optical properties than typical configurations for light trapping due to its high transparency at the front and high haze at the back. In addition, we noticed that the absorption of the BR has a strong influence on the solar modules. We obtained a superior ZnO:B BR with high haze and low absorption by controlling the doping gas ratio (B2H6/DEZ). As the doping gas ratio of ZnO:B BR decreases, the haze increases due to a rougher surface morphology, and the absorption decreases due to reduced free carrier absorption. The solar modules with a ZnO:B BR in a lower doping gas ratio show relatively higher Pmax for the same i-μc-Si layer thickness. This results from an increased Isc due to higher haze and lower absorption. In addition, the ZnO:B BR with a low doping gas ratio was found to be effective in reducing the i-μc-Si layer thickness because there are more chances for trapping the light at the i-μc-Si layer. We could reduce the i-μc-Si layer thickness by about 28% for the equivalent Pmax level by lowering the doping gas ratio. We successfully applied the ZnO:B BR with high haze and low absorption into a triple-junction thin film silicon solar cell and achieved a new record, improving on our previous world record

Refraction traveltime tomography using damped monochromatic wavefield

For complicated earth models, wave-equation–based refraction-traveltime tomography is more accurate than ray-based tomography but requires more computational effort. Most of the computational effort in traveltime tomography comes from computing traveltimes and their Fr´echet derivatives, which for ray-based methods can be computed directly. However, in most wave-equation traveltime-tomography algorithms, the steepest descent direction of the objective function is computed by the backprojection algorithm, without computing a Fr ´echet derivative directly. We propose a new wave-based refraction-traveltime– tomography procedure that computes Fr´echet derivatives directly and efficiently. Our method involves solving a damped-wave equation using a frequency-domain, finite-element modeling algorithm at a single frequency and invoking the reciprocity theorem. A damping factor, which is commonly used to suppress wraparound effects in frequency-domain modeling, plays the role of suppressing multievent wavefields. By limiting the wavefield to a single first arrival, we are able to extract the first-arrival traveltime from the phase term without applying a time window. Computing the partial derivative of the damped wave-equation solution using the reciprocity theorem enables us to compute the Fr ´echet derivative of amplitude, as well as that of traveltime, with respect to subsurface parameters. Using the Marmousi-2 model, we demonstrate numerically that refraction traveltime tomography with large-offset data can be used to provide the smooth initial velocity model necessary for prestack depth migration.This work was financially supported by the National Laboratory Project of the Ministry of Science and Technology and the Brain Korea 21 project of the Ministry of Education. We are also grateful to Prof. K. J. Marfurt of the University of Houston and Dr. M. Schoenberger for editing our manuscript

Improved frequency-domain elastic wave modeling using weighted-averaging difference operators

We develop a new finite-difference scheme that reduces the number of grid points per wavelength required in frequency-domain elastic modeling. Our approach computes weighted averages of the spatial secondorder derivative and the mass acceleration terms using a 25-point computational stencil. By determining the weighting coefficients to minimize numerical dispersion and numerical anisotropy, we reduce the number of grid points to 3.3 per shear wavelength, with a resulting error in velocities smaller than 1%. Our choice of grid points reduces the computer memory needed to store the complex impedance matrix to 4% of that for a conventional second-order scheme and to 54% of that for a combined second-order scheme. The 25-point weighted averaging scheme of this paper makes it possible to accurately simulate realistic models. Numerical examples show that this technique can achieve the same accurate solutions with fewer grid points than those from previous frequency-domain second-order schemes. Our technique can be extended directly to 3-D elastic modeling; the computational efficiency will be even greater than that realized for 2-D models

Hypocomplementemic Urticarial Vasculitis in Systemic Lupus Erythematosus

Urticarial vasculitis is characterized clinically by urticarial skin lesions and histologically by leukocytoclastic vasculitis. Hypocomplementemic urticarial vasculitis is associated with connective tissue diseases such as systemic lupus erythematosus (SLE). We report a case of urticarial vasculitis that preceded manifestations of SLE

Venous Hemangioma of Parapharyngeal Space with Calcification

A hemangioma of the parapharyngeal space (PPS) is an extremely rare tumor and is responsible for 0.5-1% of all tumors occurring in the PPS. We report a case of PPS venous hemangioma in a 49-year-old woman presenting with diffuse swelling in the submandibular region. A preoperative computed tomography (CT) scan showed a cystic mass with multiple calcifications in the PPS. The calcific nodules were round and about 2 mm in diameter. The hemangioma was completely resected via a transcervical approach. During surgery, we found several calcific nodules, which represented phleoboliths or areas of thrombosis with dystrophic calcification. Despite its rarity, a venous hemangioma of the PPS should be considered in a differential diagnosis when a cystic mass with calcification is found by CT scan. To our knowledge, this is the first reported case of a PPS venous hemangioma; we describe its pathognomonic findings on imaging

Effects of Dietary Lipid Source and Level on Growth Performance, Blood Parameters and Flesh Quality of Sub-adult Olive Flounder ()

This study was conducted to investigate the effects of dietary lipid source and level on growth performance, blood parameters, fatty acid composition and flesh quality of sub-adult olive flounder Paralichthys olivaceus. Eight experimental diets were formulated to contain 5% squid liver oil (SLO), 5% linseed oil (LO), 5% soybean oil (SO), a mixture of 1% squid liver oil, 2% linseed oil and 2% soybean oil (MIX), no lipid supplementation with high protein level (LL-HP), 10% squid liver oil (HL-SLO), a mixture of 1% squid liver oil, 4.5% linseed oil and 4.5% soybean oil (HL-VO), and 1% squid liver oil with high starch level (LL-HC), respectively. Two replicate groups of fish (average initial weight of 296 g) were fed the diets for 17 wks. After 5 wks, 11 wks and the end of the feeding trial, five fish from each tank were randomly sampled for analysis of body composition. At the end of the feeding trial, final mean weight of fish fed the LL-HP diet was significantly (p<0.05) higher than that of fish fed the HL-VO diet, but did not differ significantly from those of fish fed the SLO, LO, SO, MIX, HL-SLO and LL-HC diets. Fish fed the LL-HP diet showed significantly higher feed efficiency than fish fed the LO, HL-SLO and HL-VO diets. Feed efficiency of fish fed the LO, SO and MIX diets were similar to those of fish fed the SLO and HL-SLO diets. Fish fed the HL-SLO diet showed significantly higher total cholesterol content in plasma compared with other diets. Fatty acid composition of tissues was reflected by dietary fatty acid composition. The highest linoleic (LA) and linolenic acid (LNA) contents in the dorsal muscle were observed in fish fed the SO and LO diets, respectively, regardless of feeding period. The highest eicosapentaenoic acid (EPA) content in the dorsal muscle was observed in fish fed the LL-HP and LL-HC diets after 11 and 17 weeks of feeding, respectively. Fish fed the SLO and HL-SLO diets showed higher docosahexaenoic acid (DHA) content than that of other treatments after 11 and 17 weeks of feeding, respectively. Dietary inclusion of vegetable oils reduced n-3 HUFA contents in the dorsal muscle and liver of fish. The n-3 HUFA contents in tissues of fish fed the SLO and HL-SLO diets were higher than those of fish fed other diets, except for the LL-HP and LL-HC diets. Hardness, gel strength, chewiness and cohesiveness values of dorsal muscle in fish were significantly affected by dietary lipid source. The results of this study indicate that fish oil in fish meal based diets for sub-adult olive flounder could be replaced by soybean oil and linseed oil without negative effects on growth and feed utilizatio

Immunoglobulin G Subclass Deficiency is the Major Phenotype of Primary Immunodeficiency in a Korean Adult Cohort

Primary immunodeficiency disease (PID) is a rare disorder in adults. Most often, serious forms are detected during infancy or childhood. However, mild forms of PID may not be diagnosed until later in life, and some types of humoral immunodeficiency may occur in adulthood. The purpose of this study was to identify clinical features of PID in Korean adults. A retrospective study was performed on 55 adult patients who were diagnosed as PID between January 1998 and January 2009 at a single tertiary medical center in Korea. IgG subclass deficiency was the most common phenotype (67%, 37/55), followed by total IgG deficiency (20%, 11/55), IgM deficiency (7%, 4/55), common variable immunodeficiency (2%, 1/55), and X-linked agammaglobulinemia (2%, 1/55). IgG3 and IgG4 were the most affected subclasses. Upper and lower respiratory tract infections (76%) were the most frequently observed symptoms, followed by multiple site infection (11%), urinary tract infection, and colitis. Bronchial asthma, rhinitis, and several autoimmune diseases were common associated diseases. IgG and IgG subclass deficiency should be considered in adult patients presenting with recurrent upper and lower respiratory infections, particularly in those with respiratory allergies or autoimmune diseases

In-Situ Wettability Analysis of Al Coating Influence on Hot-Dip Galvanizing Properties of Advanced High-Strength Steels

We investigated the influence of steel surface properties on the wettability of zinc (Zn). Our main objective is to address the selective oxidation of solute alloying elements and enhance the wetting behavior of Zn on advanced high strength steel (AHSS) by employing an aluminum (Al) interlayer through the physical vapor deposition technique. The deposition of an Al interlayer resulted in a decrease in contact angle and an increase in spread width as the molten Zn interacted with the Al interlay on the steel substrate. Importantly, the incorporation of an Al interlayer demonstrated a significant improvement in wettability by substantially increasing the work of adhesion compared to the uncoated AHSS substrate