Performance Evaluation / Downtime Analysis of a Floating Liquefied Natural Gas Facility

Numerical modeling of a particular Floating Liquefied Natural Gas (FLNG) facility, targeting on Prelude FLNG, was done to find an appropriate design of the FLNG including downtime in the specific field conditions. Hull/mooring coupled FLNG models with different vertical mass distributions (represented by the center of gravity’s vertical coordinates, ZCGs) are tested under complex environmental conditions of sea-wave, wind, current, and swell. WAMIT is used for the hydrodynamic analysis in frequency domain, and the time-series of motions under swell-excluded conditions are obtained by using CHARM3D. The time-series of linear swell-induced motions are separately obtained from the Response Amplitude Operators (RAOs, results form WAMIT). The consequential time-series of motions for the combined conditions are obtained by linearly superposing the two separate results. Each of the two split environmental conditions shows very distinct effects on roll motion about the varied ZCGs. Thus, the test results enable to estimate the proper natural periods for the floating system, which provides a reference model for further analyses of several modifications under practical assumptions. One scenario assumes a design modification with reduced weight in the topside facilities, which roughly reflects a conceptual design of the FLNG introduced by Shell. The other scenario is more practical, assuming an operational stage of less stored volume, by simply reducing the hull weight. The motional characteristics differentiated by these two scenarios are investigated through their annual performances based on two heading strategies. Performance evaluation can be done by estimating the downtime of the FLNG. In this study, the typical operation limits for topside facilities of FLNGs, 2° of roll/pitch, are compared with the maximum magnitudes of the roll/pitch angles during 3-hour time series of motion. From a sample of metocean data, only dominant waves that can cause downtime are employed to check the possibility of downtime, while the minor wave system’s joint conditions are excluded. Once the excessive weather conditions that induce downtime are defined by the combinations of Tp (peak period of waves) and Hs (significant wave height), the total downtime periods including recovery hours can be estimated throughout a year. As a result, the operability of the FLNG was very sensitive to the variation of topside weights, whereas the lighter-hull assumption brought negligible differences. These outcomes consequently demonstrate that the natural periods of an offshore system should be properly tuned based on the local sea states, and any modification of topside designs that includes nontrivial weight changes requires careful analysis. Moreover, the FLNG heading strategy by Dynamic Positioning (DP) system may have great impact on the operability, and seasonally-varied heading strategies are recommended for the FLNG to minimize downtime

Overlapping functions of the MAP4K family kinases Hppy and Msn in Hippo signaling

The Hippo (Hpo) tumor suppressor pathway is an evolutionarily conserved signaling pathway that controls tissue growth and organ size in species ranging from Drosophila to human, and its malfunction has been implicated in many types of human cancer. In this study, we conducted a kinome screen and identified Happyhour (Hppy)/MAP4K3 as a novel player in the Hpo pathway. Our biochemical study showed that Hppy binds and phosphorylates Wts. Our genetic experiments suggest that Hppy acts in parallel and partial redundantly with Misshapen (Msn)/MAP4K4 to regulate Yki nuclear localization and Hpo target gene expression in Drosophila wing imaginal discs. Furthermore, we showed that cytoskeleton stress restricts Yki nuclear localization through Hppy and Msn when Hpo activity is compromised, thus providing an explanation for the Wts-dependent but Hpo-independent regulation of Yki in certain contexts. Our study has unraveled an additional layer of complexity in the Hpo signaling pathway and laid down a foundation for exploring how different upstream regulators feed into the core Hpo pathway

Effect of Roasting and Brewing on the Antioxidant and Antiproliferative Activities of Tartary Buckwheat.

We evaluated the effect of the roasting and brewing conditions of Tartary buckwheat (TB), which is widely used in infusion teas, on its antioxidant and antiproliferative activities in vitro. TB was roasted at 210 °C for 10 min and brewed at a high temperature for a short time (HTST; 85-90 °C, 3 min) or at room temperature for a long time (RTLT; 25-30 °C, 24 h). Roasted TB (RTB) tea brewed at RTLT had the highest total polyphenol content (TPC) and total flavonoid content (TFC) among the four TB teas for different roasting and brewing conditions. Moreover, RTB brewed at RTLT showed the greatest 2,2-diphenyl-1-picrylhydrazyl-, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)-, and alkyl-scavenging activities. The TB tea brewed at RTLT had higher Fe2+-chelating activity than that brewed at HTST, irrespective of roasting. Moreover, RTB tea brewed at RTLT inhibited the proliferation of human pancreatic and breast cancer cells. Overall, RTB-RTLT displayed the largest effect on antioxidant and antiproliferative effects. Finally, rutin was found to possess the most pronounced effect on the antioxidant and antiproliferative activities of the TB teas. These results indicate that the antioxidant and antiproliferative activities of RTB are enhanced by RTLT brewing

Accelerating and Supersonic Density Fluctuations in Coronal Hole Plumes: Signature of Nascent Solar Winds

Slow magnetoacoustic waves in a static background provide a seismological tool to probe the solar atmosphere in the analytic frame. By analyzing the spatiotemporal variation of the electron number density of plume structure in coronal holes above the limb for a given temperature, we find that the density perturbations accelerate with supersonic speeds in the distance range from 1.02 to 1.23 solar radii. We interpret them as slow magnetoacoustic waves propagating at about the sound speed with accelerating subsonic flows. The average sonic height of the subsonic flows is calculated to be 1.27 solar radii. The mass flux of the subsonic flows is estimated to be 44.1$\%$ relative to the global solar wind. Hence, the subsonic flow is likely to be the nascent solar wind. In other words, the evolution of the nascent solar wind in plumes at the low corona is quantified for the first time from imaging observations. Based on the interpretation, propagating density perturbations present in plumes could be used as a seismological probe of the gradually accelerating solar wind.Comment: Accepted for publication in ApJL, 11 pages, 5 figure

2D solar wind speeds from 6 to 26 solar radii in solar cycle 24 by using Fourier filtering

Measurement of the solar wind speed near the Sun is important for understanding the acceleration mechanism of the solar wind. In this study, we determine 2D solar wind speeds from 6 to 26 solar radii by applying Fourier motion filters to \textit{SOHO}/LASCO C3 movies observed from 1999 to 2010. Our method successfully reproduces the original flow speeds in the artificially generated data as well as streamer blobs. We measure 2D solar wind speeds from 1-day to 1-year timescales and their variation in solar cycle 24. We find that the solar wind speeds at timescales longer than a month in the solar maximum period are relatively uniform in the azimuthal direction, while they are clearly bimodal in the minimum period, as expected from the \textit{Ulysses} observations and IPS reconstruction. The bimodal structure appears at around 2006, becomes most distinctive in 2009, and abruptly disappears in 2010. The radial evolution of the solar wind speeds resembles the Parker's solar wind solution.Comment: 7 pages, 5 figures; accepted by PR

An Angiotensin I Converting Enzyme Polymorphism Is Associated with Clinical Phenotype When Using Differentiation-Syndrome to Categorize Korean Bronchial Asthma Patients

In this study, genetic analysis was conducted to investigate the association of angiotensin I converting enzyme (ACE) gene polymorphism with clinical phenotype based on differentiation-syndrome of bronchial asthma patients. Differentiation-syndrome is a traditional Korean medicine (TKM) theory in which patients are classified into a Deficiency Syndrome Group (DSG) and an Excess Syndrome Group (ESG) according to their symptomatic classification. For this study, 110 participants were evaluated by pulmonary function test. Among them, 39 patients were excluded because they refused genotyping. Of the remaining patients, 52 with DSG of asthma (DSGA) and 29 with ESG of asthma (ESGA), as determined by the differentiation-syndrome techniques were assessed by genetic analysis. ACE insertion/deletion (I/D) polymorphism analysis was conducted using polymerase chain reaction (PCR). Student's t, chi-square, Fisher and Hardy-Weinberg equilibrium tests were used to compare groups. No significant differences in pulmonary function were observed between DSGA and ESGA. The genotypic frequency of ACE I/D polymorphism was found to differ slightly between DSGA and ESGA (P = .0495). However, there were no significant differences in allelic frequency observed between DSGA and ESGA (P = .7006, OR = 1.1223). Interestingly, the allelic (P = .0043, OR = 3.4545) and genotypic (P = .0126) frequencies of the ACE I/D polymorphism in female patients differed significantly between DSGA and ESGA. Taken together, the results presented here indicate that the symptomatic classification of DSGA and ESGA by differentiation-syndrome in Korean asthma patients could be useful in evaluation of the pathogenesis of bronchial asthma

Effect of 660 nm Light-Emitting Diode on the Wound Healing in Fibroblast-Like Cell Lines

Light in the red to near-infrared (NIR) range (630–1000 nm), which is generated using low energy laser or light-emitting diode (LED) arrays, was reported to have a range of beneficial biological effects in many injury models. NIR via a LED is a well-accepted therapeutic tool for the treatment of infected, ischemic, and hypoxic wounds as well as other soft tissue injuries in humans and animals. This study examined the effects of exposure to 660 nm red LED light at intensities of 2.5, 5.5, and 8.5 mW/cm2 for 5, 10, and 20 min on wound healing and proliferation in fibroblast-like cells, such as L929 mouse fibroblasts and human gingival fibroblasts (HGF-1). A photo illumination-cell culture system was designed to evaluate the cell proliferation and wound healing of fibroblast-like cells exposed to 600 nm LED light. The cell proliferation was evaluated by MTT assay, and a scratched wound assay was performed to assess the rate of migrating cells and the healing effect. Exposure to the 660 nm red LED resulted in an increase in cell proliferation and migration compared to the control, indicating its potential use as a phototherapeutic agent