Study of Floating Wind Turbine with Modified Tension Leg Platform Placed in Regular Waves

In this study, the typical ocean environment was simulated with the aim to investigate the dynamic response under various environmental conditions of a Tension Leg Platform (TLP) type floating offshore wind turbine system. By applying Froude scaling, a scale model with a scale of 1:200 was designed and model experiments were carried out in a lab-scale wave flume that generated regular periodic waves by means of a piston-type wave generator while a wave absorber dissipated wave energy on the other side of the channel. The model was designed and manufactured based on the standard prototype of the National Renewable Energy Laboratory (NREL) 5 MW offshore wind turbine. In the first half of the study, the motion and structural responses for operational wave conditions of the North Sea near Scotland were considered to investigate the performance of a traditional TLP floating wind turbine compared with that of a newly designed TLP with added mooring lines. The new mooring lines were attached with the objective of increasing the horizontal stiffness of the system and thereby reducing the dominant motion of the TLP platform (i.e., the surge motion). The results of surge translational motions were obtained both in the frequency domain, using the response amplitude operator (RAO), and in the time domain, using the omega arithmetic method for the relative velocity. The results obtained show that our suggested concept improves the stability of the platform and reduces the overall motion of the system in all degrees-of-freedom. Moreover, the modified design was verified to enable operation in extreme wave conditions based on real data for a 100-year return period of the Northern Sea of California. The loads applied by the waves on the structure were also measured experimentally using modified Morison equation—the formula most frequently used to estimate wave-induced forces on offshore floating structures. The corresponding results obtained show that the wave loads applied on the new design TLP had less amplitude than the initial model and confirmed the significant contribution of the mooring lines in improving the performance of the system

Spray Formation of a Liquid Carbon Dioxide-Water Mixture at Elevated Pressures

Liquid carbon dioxide-assisted (LCO2-assisted) atomization can be used in coal-water slurry gasification plants to prevent the agglomeration of coal particles. It is essential to understand the atomization behavior of the water-LCO2 mixture leaving the injector nozzle under various conditions, including the CO2 blending ratio, injection pressure, and chamber pressure. In this study, the flash-atomization behavior of a water-LCO2 mixture was evaluated with regard to the spray angle and penetration length during a throttling process. The injector nozzle was mounted downstream of a high-pressure spray-visualization system. Based on the results, the optimal condition for the effective transport of coal particles was proposed

Battery-operated portable PCR system with enhanced stability of Pt RTD.

This paper reports an outdoor-use polymerase chain reaction (PCR) technology in which stability of resistance temperature detectors (RTDs) is remarkably improved. A thin-film RTD made of non-annealed Pt shows accuracy degradation because the resistance of the RTD tends to decrease during the PCR operation. Thus, the annealing process is applied to the Pt RTD to improve the stability, which is a prerequisite to the accurate measurement of the absolute temperature. Both heaters and the RTD are fabricated on a thin quartz substrate whose melting temperature is high enough for annealing. The performances in the PCR time and power consumption are enhanced by reducing the size of the heater chips with no degradation in the temperature uniformity. A spring-loaded electrode is employed to simplify the procedure of electrical connection to the thermal controller and loading/unloading of the PCR chip. The contact area of the electrical connection is so small that the conductive thermal resistance increases; thereby small heat dissipation can be exploited for low-power operation. The stability of the RTD is experimentally confirmed in terms of resistance variation over repeated PCR operations (four times). The least variation of 0.005%, which corresponds to a negligible temperature variation of 0.038 °C for the PCR, is achieved from the RTD annealed for 5 min at 450 °C. The gel-electrophoresis result indicates that the PCR performance of the proposed system using a film-type PCR chip is comparable to that of a conventional system using a vial tube despite its low power consumption

Nanovesicle-Based Bioelectronic Nose for the Diagnosis of Lung Cancer from Human Blood

A human nose-mimetic diagnosis system that can distinguish the odor of a lung cancer biomarker, heptanal, from human blood is presented. Selective recognition of the biomarker is mimicked in the human olfactory system. A specific olfactory receptor recognizing the chemical biomarker is first selected through screening a library of human olfactory receptors (hORs). The selected hOR is expressed on the membrane of human embryonic kidney (HEK)-293 cells. Nanovesicles containing the hOR on the membrane are produced from these cells, and are then used for the functionalization of single-walled carbon nanotubes. This strategy allows the development of a sensitive and selective nanovesicle-based bioelectronic nose (NvBN). The NvBN is able to selectively detect heptanal at a concentration as low as 1 x 10(-14) m, a sufficient level to distinguish the blood of a lung cancer patient from the blood of a healthy person. In actual experiments, NvBN could detect an extremely small increase in the amount of heptanal from human blood plasma without any pretreatment processes. This result offers a rapid and easy method to analyze chemical biomarkers from human blood in real-time and to diagnose lung cancer.OAIID:oai:osos.snu.ac.kr:snu2014-01/102/0000002410/3SEQ:3PERF_CD:SNU2014-01EVAL_ITEM_CD:102USER_ID:0000002410ADJUST_YN:YEMP_ID:A002014DEPT_CD:458CITE_RATE:0FILENAME:3. (2014.3) nanovesicle-based bioelectronic nose for the diagnosis of.pdfDEPT_NM:화학생물공학부SCOPUS_YN:NCONFIRM:

Real-time monitoring of geosmin and 2-methylisoborneol, representative odor compounds in water pollution using bioelectronic nose with human-like performance

A bioelectronic nose for the real-time assessment of water quality was constructed with human olfactory receptor (hOR) and single-walled carbon nanotube field-effect transistor (swCNT-FET). Geosmin (GSM) and 2-methylisoborneol (MIB), mainly produced by bacteria, are representative odor compounds and also indicators of contamination in the water supply system. For the screening of hORs which respond to these compounds, we performed CRE-luciferase assays of the two odorants in heterologous cell system. Human OR51S1 for GSM and OR3A4 for MIB were selected, and nanovesicles expressing the hORs on surface were produced from HEK-293 cell. Carbon nanotube field-effect transistor was functionalized with the nanovesicles. The bioelectronic nose was able to selectively detect GSM and MIB at concentrations as low as a 10 ng L−1. Furthermore, detection of these compounds from the real samples such as tap water, bottled water and river water was available without any pretreatment processes.OAIID:oai:osos.snu.ac.kr:snu2015-01/102/0000002410/12ADJUST_YN:YEMP_ID:A002014DEPT_CD:458CITE_RATE:6.409DEPT_NM:화학생물공학부SCOPUS_YN:NCONFIRM:

Screening of target-specific olfactory receptor and development ofolfactory biosensor for the assessment of fungal contamination in grain

We herein report an integrated olfactory system to carbon nanotube platforms for biosensing appli-cations. In particular, this system can be used for the real-time monitoring of fungal contamination ingrain through detecting 1-octen-3-ol, which is specifically generated from contaminated grain. A spe-cific human olfactory receptor (OR) that recognizes 1-octen-3-ol was found using a cyclic adenosinemonophosphate (cAMP) response element (CRE)-reporter gene assay. Then, OR-containing nanovesi-cles were produced from human embryonic kidney (HEK)-293 cells. The nanovesicles, which generateolfactory signals using endogenous cellular components and over-expressed ORs, were integrated intosingle-walled carbon nanotubes field-effect transistors (SWNT-FETs). The nanovesicles and SWNT-FETsplay roles in perceiving specific odorants, and in amplifying cellular signals, respectively. Thus, thenanovesicle-integrated device was able to detect 1-octen-3-ol with excellent sensitivity and selectiv-ity, similar to the original olfactory system. This system can be effectively utilized for the real-timemeasurement of fungal contamination in grain.OAIID:oai:osos.snu.ac.kr:snu2015-01/102/0000002410/5EMP_ID:A002014DEPT_CD:458FILENAME:2. (2015.04) screening of target-specific olfactory receptor and development of.pdfDEPT_NM:화학생물공학부SCOPUS_YN:NCONFIRM:

A peptide receptor-based bioelectronic nose for the real-time determination of seafood quality

We herein report a peptide receptor-based bioelectronic nose (PRBN) that can determine the quality of seafood in real-time through measuring the amount of trimethylamine (TMA) generated from spoiled seafood. The PRBN was developed using single walled-carbon nanotube field-effect transistors (SWNT-FETs) functionalized with olfactory receptor-derived peptides (ORPs) which can recognize TMA and it allowed us to sensitively and selectively detect TMA in real-time at concentrations as low as 10 fM. Utilizing these properties, we were able to not only determine the quality of three kinds of seafood (oyster, shrimp, and lobster), but were also able to distinguish spoiled seafood from other types of spoiled foods without any pretreatment processes. Especially, the use of small synthetic peptide rather than the whole protein allowed PRBNs to be simply manufactured through a single-step process and to be reused with high reproducibility due to no requirement of lipid bilayers. Furthermore, the PRBN was produced on a portable scale making it effectively useful for the food industry where the on-site measurement of seafood quality is required. (C) 2012 Elsevier B.V. All rights reserved.This study was supported by the National Research Foundation of Korea (NRF) grant funded by the Ministry of Education, Science and Technology (MEST). THP thanks the support from the NRF grant (Nos. 2011-0020984, 2012-0000144, 2012K001365). SH thanks the support from the NRF grant (Nos. 2012-0000117, 2012K001366).OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000002410/2SEQ:2PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000002410ADJUST_YN:YEMP_ID:A002014DEPT_CD:458CITE_RATE:5.602FILENAME:a peptide receptor-based.pdfDEPT_NM:화학생물공학부EMAIL:[email protected]_YN:NCONFIRM:

A bioelectronic sensor based on canine olfactory nanovesicle???carbon nanotube hybrid structures for the fast assessment of food quality

We developed an olfactory-nanovesicle-fused carbon-nanotube-transistor biosensor (OCB) that mimics the responses of a canine nose for the sensitive and selective detection of hexanal, an indicator of the oxidation of food. OCBs allowed us to detect hexanal down to 1 fM concentration in real-time. Significantly, we demonstrated the detection of hexanal with an excellent selectivity capable of discriminating hexanal from analogous compounds such as pentanal, heptanal, and octanal. Furthermore, we successfully detected hexanal in spoiled milk without any pretreatment processes. Considering these results, our sensor platform should offer a new method for the assessment of food quality and contribute to the development of portable sensing devices