• Title/Summary/Keyword: multi-cells

Search Result 840, Processing Time 0.03 seconds

Surface Analysis and Conversion Efficiency of Multi-crystalline Silicon Solar Cell by Wet Chemical Etching (습식 화학 식각에 의한 다결정 실리콘 웨이퍼의 표면 분석 및 효율 변화)

  • Park, Seok-Gi;Do, Kyeom-Seon;Song, Hee-Eun;Kang, Gi-Hwan;Ahn, Hyung-Keun;Han, Deuk-Young
    • 한국태양에너지학회:학술대회논문집
    • /
    • 2011.04a
    • /
    • pp.111-115
    • /
    • 2011
  • Surface Texturing is an essential process for high efficiency in multi-crystalline silicon solar cell. In order to reduce the reflectivity, there are two major methods; proper surface texturing and anti-reflection coating. For texturization, wet chemical etching is a typical method for multi-crystalline silicon. The chemical solution for wet etching consists of HF, $NHO_3$, DI and $CH_3COOH$. We carried out texturization by the change of etching time like 15sec, 30sec, 45sec, 60sec and measured the reflectivity of textured wafers. As making the silicon solar cells, we obtained the conversion efficiency and relationship between texturing condition and solar cell characteristics. The reflectivity from 300nm to 1200nm was the lowest with 15 sec texturing time and 60 sec texturing time showed almost same reflectivity as bare one. The 45 sec texturing time showed the highest conversion efficiency.

  • PDF

Liquid Crystal Alignment on Multi-stacked Layer HfO2 Thin Films Using a Solution-process (용액 공정 기반의 다중 적층된 HfO2 박막 상에서의 액정 배향)

  • Kim, Dai-Hyun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.26 no.11
    • /
    • pp.821-825
    • /
    • 2013
  • Effect of multi-stacked layer (MSL), 0.1 mol (M) and 0.3 mol (M) hafnium oxide ($HfO_2$) alignment layers were fabricated via a solution-process for LCs orientation. The solutions were spin-coated and annealed in a furnace. MSL consists of three sub-layers using 0.1 M solution, mono-layer (ML) is composed of 0.3 M $HfO_2$ solution. Then ion-beam irradiation was treated with 1.8 keV for 2 min. $HfO_2$-based LC cells were investigated through photographs, pre-tilt angle using crystal rotation method, X-ray photoelectron spectroscopy (XPS) measurement, and surface roughness using atomic force microscopy(AFM) for their characteristic research. Good LC orientation characteristics were observed on MSL $HfO_2$ surface. The LC alignment mechanism on MSL $HfO_2$ and ML $HfO_2$ surfaces was attributed to van der Waals (VDW) interaction between the LC molecular and substrate surface.

Breast Tumor Cell Nuclei Segmentation in Histopathology Images using EfficientUnet++ and Multi-organ Transfer Learning

  • Dinh, Tuan Le;Kwon, Seong-Geun;Lee, Suk-Hwan;Kwon, Ki-Ryong
    • Journal of Korea Multimedia Society
    • /
    • v.24 no.8
    • /
    • pp.1000-1011
    • /
    • 2021
  • In recent years, using Deep Learning methods to apply for medical and biomedical image analysis has seen many advancements. In clinical, using Deep Learning-based approaches for cancer image analysis is one of the key applications for cancer detection and treatment. However, the scarcity and shortage of labeling images make the task of cancer detection and analysis difficult to reach high accuracy. In 2015, the Unet model was introduced and gained much attention from researchers in the field. The success of Unet model is the ability to produce high accuracy with very few input images. Since the development of Unet, there are many variants and modifications of Unet related architecture. This paper proposes a new approach of using Unet++ with pretrained EfficientNet as backbone architecture for breast tumor cell nuclei segmentation and uses the multi-organ transfer learning approach to segment nuclei of breast tumor cells. We attempt to experiment and evaluate the performance of the network on the MonuSeg training dataset and Triple Negative Breast Cancer (TNBC) testing dataset, both are Hematoxylin and Eosin (H & E)-stained images. The results have shown that EfficientUnet++ architecture and the multi-organ transfer learning approach had outperformed other techniques and produced notable accuracy for breast tumor cell nuclei segmentation.

Human Fibroblast-derived Multi-peptide Factors and the Use of Energy-delivering Devices in Asian Patients

  • Suh, Sang Bum;Ahn, Keun Jae;Chung, Hye Jin;Suh, Ji Youn;Cho, Sung Bin
    • Medical Lasers
    • /
    • v.9 no.1
    • /
    • pp.12-24
    • /
    • 2020
  • Human fibroblast-derived multi-peptide factors (MPFs) have been used during treatments with energy-delivering modalities to enhance energy-induced tissue reactions. Human fibroblast-derived MPFs, which include a range of growth factors and chemoattractive factors, activate and recruit fibroblasts and endothelial cells, as well as promote extracellular matrix deposition, all of which are crucial to wound repair. Interestingly, fibroblasts from different species or anatomical sites exhibit distinct transcriptional properties with high heterogeneity. In addition, the patterns of MPF secretion can differ under a range of experimental conditions. Therefore, the use of allogeneic fibroblasts and proper cultivation thereof are necessary to obtain MPFs that can enhance the epithelial-mesenchymal interactions during wound repair. Moreover, energy-delivering devices should be selected according to evidence demonstrating their therapeutic efficacy and safety on a pathological skin condition and the major target skin layers. This paper reviewed the histologic patterns of post-treatment tissue reactions elicited by several energy sources, including non-ablative and ablative fractional lasers, intense focused ultrasound, non-invasive and invasive radiofrequency, picosecond-domain lasers, and argon and nitrogen plasma. The possible role of the immediate application of human fibroblast-derived MPFs during wound repair was proposed.

Studies on the Developmental Processes of the Protein Body in the Ginseng(Panax ginseng C.A. Meyer) Endosperm Cell (인삼(Panax ginseng C.A. Meyer) 배유세포의 Protein Body 형성에 관한 연구)

  • Yu, Seong-Cheol;Jeong, Byung-Kap;Kim, Woo-Kap
    • Applied Microscopy
    • /
    • v.18 no.2
    • /
    • pp.141-152
    • /
    • 1988
  • The developmental processes of the protein body are studied on endosperm cells of Panax ginseng during seed maturation periods. The spherosome, mitochondria, rough endoplasmic reticulum, and ribosome are observed and then are gradually increased in early endosperm cells. Protein body developed from vesicles produced by the rough endoplasmic reticulum and was formed at the enlarged ends of rough endoplasmic reticulum. Also, vacuole-like protein body was observed in associated with rough endoplasmic reticulum. Golgi complex is observed in associated with vacuole and its vesicles containing proteinaceous granules moved and accumulated to the vacuole. Proteinaceous granules are deposited in the spherical or oval shaped vacuole and gradually, vacuole is surrounded by the multi-membranous structure. Rough endoplasmic reticulum, ribosome, Golgi complex, and vacuole are observed in associated with protein body formation.

  • PDF

Parameter Estimation of Solar Cells and MPP Prediction Using a NN-Emulator (태양전지의 파라미터 추정 및 NN 에뮬레이터를 이용한 MPP 예측)

  • 권봉재;김종하;진강규
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.28 no.6
    • /
    • pp.1010-1016
    • /
    • 2004
  • In this paper, a scheme for estimating the parameters of solar cells and a NN-based emulator for predicting the maximum power point are presented. The diode model with series and shunt resistors is used to estimate parameters highly affecting its V-I characteristic curve and both a real-coded genetic algorithm and the model adjustment technique are employed. For implementing the emulator, a multi-layered neural network incorporating with the BP algorithm is used. A set of simulation works using both field data and generated data are carried out to demonstrate the effectiveness of the proposed method.

Marker Genes for in Vitro Selection of Transgenic Plants

  • Brasileiro, Ana C.M.;Aragao, Francisco J.L.
    • Journal of Plant Biotechnology
    • /
    • v.3 no.3
    • /
    • pp.113-121
    • /
    • 2001
  • The use of a marker gene in a transformation process aims to give a selective advantage to the transformed cells, allowing them to grow faster and better, and to kill the non-transformed cells. In general, the selective gene is introduced into plant genome along with the genes of interest. In some cases, the marker gene can be the gene of interest that will confer an agronomic characteristic, such as herbicide resistance. In this review we list and discuss the use of the most common selective marker genes on plant transformation and the effects of their respective selective agents. These genes could be divided in categories according their mode of action: genes that confer resistance to antibiotics and herbicides; and genes for positive selection. The contention of the marker gene flow through chloroplast transformation is further discussed. Moreover, strategies to recover marker-free transgenic plants, involving multi-auto-transformation (MAT), co-transformation, site specific recombination and intragenomic relocation of transgenes through transposable elements, are also reviewed.

  • PDF

Descriptions of the Wood Anatomy and Safranine Impregnation in Gmelina arborea Roxb. from Bangladesh

  • Ahmed, Sheikh Ali;Chun, Su-Kyoung
    • Journal of the Korea Furniture Society
    • /
    • v.18 no.2
    • /
    • pp.100-105
    • /
    • 2007
  • In this report, we describe the anatomical features of Gmelina arborea Roxb. belong to the genera of Verbenaceae native to Bangladesh and safranine penetration depth in radial and longitudinal directions. The wood of this species was characterized mostly by distinct growth ring boundaries, diffuse-porous, simple perforations, alternate non-vestured intervessel pits, and relatively short vessel elements and medium fibers. Thin to thick walled septate fibers with simple to minutely bordered pits are confined to the radial walls. Tyloses are common. They are paratracheal axial parenchyma vascicnetric and confluent. Rays not higher than 1milimeter are found, and larger rays commonly 4 to 5 seriate are dominantly present, as are multi seriate rays composed of a procumbent ray with 1 row of square or upright cells. Acicular crystals are present in ray cells. Another experiment was taken under consideration to observe the liquid penetration depth in longitudinal and radial directions using safranine. It was found that safranine penetrated easily in longitudinal direction and sapwood was more permeable than heartwood.

  • PDF

A Study of low cost and high efficiency Solar Cell using SOD(spin on doping) (SOD(Spin On Doping)법을 이용한 저가 고효율 태양전지에 관한 연구)

  • Park, Sung-Hyun;Kim, Kyoung-Hae;Mon, Sang-Il;Kim, Dae-Won;Yi, Jun-Sin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2002.07b
    • /
    • pp.1054-1056
    • /
    • 2002
  • High temperature Kermal diffusion from $POCl_3$ source usually used for conventional process through put of a cell manufacturing line and potentially reduce cell efficiency through bulk like time degradation. To fabricate high efficiency solar cells with minimal thermal processing, spin-on-doping(SOD) technique can be employed to emitter diffusion of a silicon solar cell. A technique is presented to emitter doping of a mono-crystalline solar cell using spin-on doping (SOD). Moreover it is shown that the sheet resistance variation with RTA temperature and time fer mono-crystalline and multi-crystalline silicon samples. This novel SOD technique was successfully used to produces 11.3% efficiency l04mm by 104mm size mono-crystalline silicon solar cells.

  • PDF

Regulation of Early Steps of Chondrogenesis in the Developing Limb

  • Kang, Shin-Sung
    • Animal cells and systems
    • /
    • v.12 no.1
    • /
    • pp.1-9
    • /
    • 2008
  • In the developing limb, chondrogenesis is an important prerequisite for the formation of cartilage whose template is required for bone formation. Chondrogenesis is a tightly regulated multi-step process, including mesenchymal cell recruitment/migration, prechondrogenic condensation of the mesenchymal cells, commitment to the chondrogenic lineage, and differentiation into chondrocytes. This process is controlled exquisitely by cellular interactions with the surrounding matrix and regulating factors that initiate or suppress cellular signaling pathways and transcription of specific genes in a temporal-spatial manner. Understanding the cellular and molecular mechanisms of chondrogenesis is important not only in the context of establishing basic principle of developmental biology but also in providing research direction toward preventive and/or regenerative medicine. Here, I will overview the current understanding of cellular and molecular mechanisms contributing to prechondrogenic condensation processes, the crucial steps for chondrogenesis, focusing on cell-cell and cell-matrix interactions.