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

Point-of-care ultrasound may reduce emergency department length of stay in children with nonspecific manifestations of intussusception

Purpose To investigate whether performance of point-of-care ultrasound (POCUS) can reduce emergency department length of stay (EDLOS) for children with nonspecific manifestations of intussusception (NMI), defined as 2 or less manifestations of the classic triad of intussusception, and/or vomiting. Methods We reviewed medical records of 141 consecutive children with intussusception aged 6 years or younger who visited the emergency department of Asan Medical Center in Seoul, Korea from May 2014 through April 2016 and underwent diagnostic radiology ultrasound and pneumatic reduction. The children were grouped according to whether they underwent POCUS or not (POCUS and no POCUS groups, respectively). POCUS was performed to children with NMI by an attending emergency physician who had completed a POCUS training course endorsed by the Korean Society of Pediatric Emergency Medicine. We measured EDLOS, which consisted of door-to-reduction and observation times. These time intervals were compared between the 2 groups. Results Of 112 eligible children, 65 (58%) underwent POCUS. The median EDLOS was shorter in the POCUS group than in the no POCUS group (566 minutes, interquartile range [IQR] 497 to 765 vs. 745 minutes, IQR 551 to 981; P = 0.003). The median door-to-reduction and observation times were also shorter in the POCUS group (105 vs. 138 minutes, P < 0.001 and 440 vs. 628 minutes, P = 0.008, respectively). These differences were possibly due to the performance of POCUS and the trend toward early discharge after pneumatic reduction. We found 1 child with false negative result on POCUS, but there may have been more. Conclusion Performance of POCUS may reduce EDLOS in children with NMI

CHARACTERIZATION OF THERMOMECHANICAL PULP MADE FROM PINE TREES INFECTED WITH NEMATODES

Pine wilt is a lethal disease caused by the nematode Bursaphelenchus xylophilus. It causes tree death by blocking water and nutrient uptake in pine trees. Pine trees infected by these nematodes are used as fertilizer or fuel for thermal power plants, but their utilization is still only about 37%. To increase the utilization of the infected trees, this study investigated whether the shredded wood chips prepared from them could be used as raw materials for manufacturing thermomechanical pulp (TMP) and chemithermomechanical pulp (CTMP). TMP and CTMP prepared from the infected pine chips showed fewer pitch contents and better strength properties than those made from domestic pine. In conclusion, if the nematode-infected pine was used as raw materials for manufacturing TMP and CTMP, it is expected that it would contribute to the diversification of raw materials along with a high-temperature insecticidal effect. Keywords: Pine wilt, nematode disease, thermomechanical pulp, chemithermomechanical pulp, pulp strength, insecticidal effect &nbsp

COMPARISON OF THE EFFECT OF TMP PITCH CONTROL AGENTS WITH DIFFERENT MECHANISMS

The pitch contained in thermomechanical pulp negatively affects paper quality, pulp, and the papermaking process. Serious pitch and stickies problems may occur in paper recycling processes. In this study, the effects of chemicals used to control the pitch in the TMP(Themomechanical Pulp) rocess were compared. The method used to analyze the pitch-control effect was to perform image analysis after using a reagent that selectively stains only the hydrophobic pitch. Three different mechanisms, namely fixation, detackification, and dispersion, were applied to solve the pitch problem from TMP. All the control agents were effective in pitch control, and, in particular, the agents related to fixation and dispersion were found to be more effective in reducing the number and area of tacky particles per unit area in sheets and white water. However, for the detackifiers and the dispersants, but not for the fixatives, it was difficult to clearly distinguish the difference of the pitch control effects according to the change in the amount of these agents through image analysis after staining

Efficient 3D Volume Reconstruction from a Point Cloud Using a Phase-Field Method

We propose an explicit hybrid numerical method for the efficient 3D volume reconstruction from unorganized point clouds using a phase-field method. The proposed three-dimensional volume reconstruction algorithm is based on the 3D binary image segmentation method. First, we define a narrow band domain embedding the unorganized point cloud and an edge indicating function. Second, we define a good initial phase-field function which speeds up the computation significantly. Third, we use a recently developed explicit hybrid numerical method for solving the three-dimensional image segmentation model to obtain efficient volume reconstruction from point cloud data. In order to demonstrate the practical applicability of the proposed method, we perform various numerical experiments