• Title/Summary/Keyword: cell harvesting

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A Simple Method for Cat Bone Marrow-derived Mesenchymal Stem Cell Harvesting

  • Jin, Guang-Zhen;Lee, Young-Soo;Choi, Eu-Gene;Cho, Kyu-Woan;Kong, Il-Keun
    • Journal of Embryo Transfer
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    • v.23 no.2
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    • pp.127-131
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    • 2008
  • Bone marrow (BM) cell harvesting is a crucial element in the isolation of mesenchymal stem cells (MSCs). A simple method for harvesting cat BM cells is described. The results show that a large number of BM cells can rapidly be harvested from the cat by this simple procedure. MSCs prepared by density-gradient method were spindle-shaped morphology with bipolar or polygonal cell bodies and strongly positive for CD9 and CD44 and negative for CD18 and CD45-like. They were capable of differentiation to adipocytic and osteocytic phenotypes when exposed to appropriate induction media. The advantages of this method are its rapidity, simplicity, low invasiveness, and low donor attrition and good outcome.

Methods to Improve Light Harvesting Efficiency in Dye-Sensitized Solar Cells

  • Park, Nam-Gyu
    • Journal of Electrochemical Science and Technology
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    • v.1 no.2
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    • pp.69-74
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    • 2010
  • Methodologies to improve photovoltaic performance of dye-sensitized solar cell (DSSC) are reviewed. DSSC is usually composed of a dye-adsorbed $TiO_2$ photoanode, a tri-iodide/iodide redox electrolyte and a Pt counter electrode. Among the photovoltaic parameters of short-circuit photocurrent density, open-circuit voltage and fill factor, short-circuit photocurrent density is the collective measure of light harvesting, charge separation and charge collection efficiencies. Internal quantum efficiency is known to reach almost 100%, which indicates that charge separation occurs without loss by recombination. Thus, light harvesting efficiency plays an important role in improvement of photocurrent. In this paper, technologies to improve light harvesting efficiency, including surface area improvement by nano-dispersion, size-dependent light scattering efficiency, bi-functional nano material, panchromatic absorption by selective positioning of three different dyes and transparent conductive oxide (TCO)-less DSSC, are introduced.

Design of On-Chip Solar Energy Harvesting Circuit with MPPT Control (MPPT 제어 기능을 갖는 온칩 빛에너지 하베스팅 회로 설계)

  • Yoon, Eun-Jung;Park, Jun-Ho;Park, Jong-Tae;Yu, Chong-Gun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2011.10a
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    • pp.425-428
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    • 2011
  • This paper presents a micro-scale solar energy harvesting circuit with a simple MPPT control. Solar Energy is harvested using a small off-chip PV cell generating output voltages under 0.5V instead of an on-chip PV cell. A simple MPPT is implemented using a pilot PV cell and utilizing the relationship between the open-circuit voltage of a PV cell ($V_{OC}$) and its MPP voltage ($V_{MPP}$). With applying the MPPT control, the designed circuit delivers the MPP voltage to load even though the loads is heavy such that the load circuit can operate properly. The proposed circuit is designed in TSMC 0.18um CMOS process.

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Interference Management Algorithm Based on Coalitional Game for Energy-Harvesting Small Cells

  • Chen, Jiamin;Zhu, Qi;Zhao, Su
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.9
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    • pp.4220-4241
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    • 2017
  • For the downlink energy-harvesting small cell network, this paper proposes an interference management algorithm based on distributed coalitional game. The cooperative interference management problem of the energy-harvesting small cells is modeled as a coalitional game with transfer utility. Based on the energy harvesting strategy of the small cells, the time sharing mode of the small cells in the same coalition is determined, and an optimization model is constructed to maximize the total system rate of the energy-harvesting small cells. Using the distributed algorithm for coalition formation proposed in this paper, the stable coalition structure, optimal time sharing strategy and optimal power distribution are found to maximize the total utility of the small cell system. The performance of the proposed algorithm is discussed and analyzed finally, and it is proved that this algorithm can converge to a stable coalition structure with reasonable complexity. The simulations show that the total system rate of the proposed algorithm is superior to that of the non-cooperative algorithm in the case of dense deployment of small cells, and the proposed algorithm can converge quickly.

Investigation on the Design Method of a Energy Harvesting Power Supply for a Smart Sensor (스마트 센서의 에너지 하베스팅 전원 공급부 설계 방안 연구)

  • Ho-Deok Jang
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.16 no.1
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    • pp.18-23
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    • 2023
  • A smart sensor is the key element to implement IoT (Internet of Things) service, as a terminal equipment. This paper investigated the design method of a power supply using energy harvesting technique for a smart sensor. the performance of a power supply using a solar cell and a piezoelectric transducer as a energy harvesting device was verified and the method to optimize a power supply was analyzed depending on the operating condition of a smart sensor. Also the method to increase a battery life cycle as a auxiliary power supply was proposed.

Effects of Sediment Harvesting on Bacterial Community Structure (골재채취가 세균군집구조에 미치는 영향)

  • Park, Ji-Eun;Lee, Young-Ok
    • Korean Journal of Environmental Biology
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    • v.24 no.2 s.62
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    • pp.172-178
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    • 2006
  • The dynamics of bacterial populations belonging to $\alpha\;\beta\;\gamma-subclass$ proteobacteria, Cytophaga-Flavobacterium (CF) group and sulfate reducing bacteria (SRB) in water column of the middle reaches of Nakdong River depending on sediment harvesting were analyzed by fluorescent in situ hybridization (FISH) at sediment harvesting site (near the Seongju bridge) and non-sediment harvesting site (near the Gumi bridge). In addition, some physico-chemical parameters such as temperature, pH, $chi-\alpha$ and electrical conductivity were measured. Regarding the number of total cell counts, cells stained by DAPI, there were no substantial quantitative differences between both sites, but those fluctuation at sediment Harvesting site was greater. And also the ratios of CFgroup and SRB to total cell counts tend to increase at sediment harvesting site with higher $chl-\alpha$, maybe due to the resuspension of sediment into water column. But the total proportion of all determined bacterial populations to total cell counts were greater at non-sediment harvesting site, compared with those at sediment harvesting site. Since the detectibility of bacteria by FISH depends on their metabolic activity, those lower proportion at the sediment harvesting site implies that sediment harvesting may lead to malfunction of those bacteria respect to nutrient recycling and subsequently negative effects on microbial food web.

Energy Harvesting from Bio-Organic Substance Using Microbial Fuel Cell and Power Conditioning System (미생물 연료 전지와 전력 조절 시스템을 이용한 생체 유기 물질로부터의 전력 생산)

  • Yeo, Jeongjin;Yang, Yoonseok
    • Journal of Biomedical Engineering Research
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    • v.38 no.5
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    • pp.242-247
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    • 2017
  • This study presents a bio-chemical energy harvesting system which can generate electric power from bioorganic substance contained in vermicompost. It produced electricity by inoculating microbial fuel cell(MFC) with earthworm-composted food waste. The generated electricity was converted into usable voltage level for mobile electronics through power conditioning circuits. The implemented prototype showed $200{\mu}W$ of maximum output electric power, which successfully supplied a beacon device which continuously transmitted data to nearby smartphone without a battery. The proposed system can help develop portable or bio-mimetic energy supply for sustainable use with further improvement.

Fabrication of an Automatic Color-Tuned System with Flexibility Using a Dry Deposited Photoanode

  • Choi, Dahyun;Park, Yoonchan;Lee, Minji;Kim, Kwangmin;Choi, Jung-Oh;Lee, Caroline Sunyong
    • International Journal of Precision Engineering and Manufacturing-Green Technology
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    • v.5 no.5
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    • pp.643-650
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    • 2018
  • A self-powered electrochromic device was fabricated on an indium tin oxide-polyethylene naphthalate flexible substrate using a dye-sensitized solar cell (DSSC) as a self-harvesting source; the electrochromic device was naturally bleached and operated under outdoor light conditions. The color of the organic electrochromic polymer, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate, was shifted from pale blue to deep blue with an antimony tin oxide film as a charge-balanced material. Electrochromic performance was enhanced by secondary doping using dimethyl sulfoxide. As a result, the device showed stable switching behavior with a high transmittance change difference of 40% at its specific wavelength of 630 nm for 6 hrs. To improve the efficiency of the solar cell, 1.0 wt.% of Ag NWs in the photoanode was applied to the $TiO_2$ photoanode. It resulted in an efficiency of 3.3%, leading to an operating voltage of 0.7 V under xenon lamp conditions. As a result, we built a standalone self-harvesting electrochromic system with the performance of transmittance switching of 29% at 630 nm, by connecting with two solar cells in a device. Thus, a self-harvesting and flexible device was fabricated to operate automatically under the irradiated/dark conditions.

A study on energy harvesting time of Solar Cell battery for Sensor node (센서 노드 배터리 충전을 위한 Solar Cell의 완충시간에 대한 연구)

  • Choi, Young-Suk;Ryu, Jeong-Tak;Kim, Kyung-Ki;Kim, H.C.
    • Journal of Korea Society of Industrial Information Systems
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    • v.16 no.1
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    • pp.31-36
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    • 2011
  • Ubiquitous network and wireless sensor networks is being applied in various fields. Located at target areas, node of wireless sensor network uses batteries as a power source. Batteries have a limited energy in sensor network applications. Also, before use, the battery must be charged and It is difficult to replace the battery. Therefore, energy harvesting technology is being researched and being developed for long life of sensor node. Especially, sola energy is being extensively researched. because that can have great amounts of energy than other environmental energy in a short time. In this study, we tested battery charging and recharging, operation of sensor node using Solar Cell. Also, monitoring data gathering and voltage Analysis showed energy harvesting time of Sola Cell battery for sensor node and operation of sensor node.

A Study on AC/DC Power Converter of Energy Harvesting for Considered to Solar Position Tracking Control (태양광 위치 추적 제어를 고려한 에너지 Harvesting AC/DC 전력 변환기 구동에 관한 연구)

  • Na, Seung-Kwon;Ku, Gi-Jun
    • Journal of Advanced Navigation Technology
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    • v.18 no.1
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    • pp.56-66
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    • 2014
  • In this paper, the solar cell need the characteristic interpreting because the solar cell changes greatly according to the isolation, temperature and load in the photovoltaic development. Moreover, to get many energy in photovoltaic development need the position tracking of the sun according to the environment change and it is necessary to control the output of solar cells up to the time. Simulation and composed microprocessor and sensor chip an power conversion system with boost converter to experiment results are performed to prove the analysis of the converter operation, and to show the possibility of energy harvesting and photovoltaic development need the position tracking small capacitance, the boost rate of boost converter was similar to 167 percent.