Autonomous Ocean Turbulence Measurements From a Moored Upwardly Rising Profiler Based on a Buoyancy-Driven Mechanism

2017 ◽  
Vol 51 (4) ◽  
pp. 12-22 ◽  
Author(s):  
Xiuyan Liu ◽  
Xin Luan ◽  
Z. Daniel Deng ◽  
Dalei Song ◽  
Shengbo Zang ◽  
...  

AbstractAn autonomous Moored Reciprocating Vertical Profiler (MRVP) has been developed and tested for measuring ocean turbulence. The MRVP is designed to combine the advantages of long-term moored measurements at specified depths with those of short-term ship-supported continuous profiling performed at high vertical resolution. The profiler is programmed to repeat vertical motions autonomously along the mooring cable based on a buoyancy-driven mechanism. A sea trial has been conducted in the South China Sea to evaluate the performance of the profiler. The shear probe data are unreliable when the flow past sensors is not sufficiently greater than an estimate of turbulent velocity. For 65% of the dataset, turbulence measurements are of high quality and the magnitude of dissipation rates is up to O(10−10) W kg−1. To minimize the contamination induced by instrument vibration and improve the estimation of turbulent kinetic energy terms, an advanced cross-spectrum algorithm is implemented to the measured shear data. The corrected spectra agreed well with the empirical Nasmyth spectrum, and dissipation rates had averagely decreased a factor of 2 and 8 times lower than the raw spectra. The autonomous MRVP is proven to be a stable platform, and the novel upward measurement provides a new perspective for measuring long-term time series of turbulence mixing.

2013 ◽  
Vol 347-350 ◽  
pp. 803-807
Author(s):  
Xin Luan ◽  
Bing Xue ◽  
Feng Mei Sun ◽  
Qi Zhi Yan ◽  
Da Lei Song

Turbulence played an important role in the evolution of the seawater energy and exchange. Multi-scale, long-term, fixed-point and continuous sampling is a new research direction in the turbulence observation. This dissertation designed high-capacity and no-vibration data storage solutions aiming at long-term, continuous turbulence observations. First a multi-scale submerged buoy observing platform is designed. Base on the turbulence observing platform, a multi-parameter data acquisition and no vibrations storage system is designed. This paper describes the hardware and software design implementation of large-capacity data storage arrays in details as well as the readability and easy operation of the transplant of FatFS. Actual test and sea trial prove the design can be achieved large-capacity data access of long-term observation of ocean turbulence base on the submerged buoy.


2017 ◽  
Vol 65 (3) ◽  

A lot has been published on the topic concussion in sports during the last years, conscience was sharpened, much was structured and defined more precisely, help tools were developed and rules changed. This article summarizes the fifth edition of the recently published guidelines of the “International Consensus Conference on Concussion in Sport”. In addition, new findings regarding gender differences and recovery will be presented, as well as the modified “return-to-sport” and the novel “return-to-school” protocols. Despite increased knowledge many questions remain such as the therapy of persistent symptoms or long-term sequelae of recurrent concussions.


Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 421
Author(s):  
Chang-Hwan Lee ◽  
Iman Mansouri ◽  
Jaehoon Bae ◽  
Jaeho Ryu

A new type of composite voided slab, the TUBEDECK (TD), which utilizes the structural function of profiled steel decks, has recently been proposed. Previous studies have confirmed that the flexural strength of TD slabs can be calculated based on the full composite contribution of the steel deck, but for long-span flexural members, the deflection serviceability requirement is often dominant. Herein, we derived a novel deflection prediction approach using the results of flexural tests on slab specimens, focusing on TD slabs. First, deflection prediction based on modifications of the current code was proposed. Results revealed that TD slabs exhibited smaller long-term deflections and at least 10% longer maximum span lengths than solid slabs, indicating their greater efficiency. Second, a novel rational method was derived for predicting deflections without computing the effective moment of inertia. The ultimate deflections predicted by the proposed method correlated closely with the deflection under maximum bending moments. To calculate immediate deflections, variation functions for the concrete strain at the extreme compression fiber and neutral axis depth were assumed with predictions in good agreement with experiments. The proposed procedure has important implications in highlighting a new perspective on the deflection prediction of reinforced concrete and composite flexural members.


Infection ◽  
2021 ◽  
Author(s):  
Ali Hamady ◽  
JinJu Lee ◽  
Zuzanna A. Loboda

Abstract Objectives The coronavirus disease 2019 (COVID-19), caused by the novel betacoronavirus severe acute respiratory syndrome 2 (SARS-CoV-2), was declared a pandemic in March 2020. Due to the continuing surge in incidence and mortality globally, determining whether protective, long-term immunity develops after initial infection or vaccination has become critical. Methods/Results In this narrative review, we evaluate the latest understanding of antibody-mediated immunity to SARS-CoV-2 and to other coronaviruses (SARS-CoV, Middle East respiratory syndrome coronavirus and the four endemic human coronaviruses) in order to predict the consequences of antibody waning on long-term immunity against SARS-CoV-2. We summarise their antibody dynamics, including the potential effects of cross-reactivity and antibody waning on vaccination and other public health strategies. At present, based on our comparison with other coronaviruses we estimate that natural antibody-mediated protection for SARS-CoV-2 is likely to last for 1–2 years and therefore, if vaccine-induced antibodies follow a similar course, booster doses may be required. However, other factors such as memory B- and T-cells and new viral strains will also affect the duration of both natural and vaccine-mediated immunity. Conclusion Overall, antibody titres required for protection are yet to be established and inaccuracies of serological methods may be affecting this. We expect that with standardisation of serological testing and studies with longer follow-up, the implications of antibody waning will become clearer.


Genetics ◽  
1996 ◽  
Vol 143 (1) ◽  
pp. 15-26 ◽  
Author(s):  
Michael Travisano ◽  
Richard E Lenski

Abstract This study investigates the physiological manifestation of adaptive evolutionary change in 12 replicate populations of Escherichia coli that were propagated for 2000 generations in a glucose-limited environment. Representative genotypes from each population were assayed for fitness relative to their common ancestor in the experimental glucose environment and in 11 novel single-nutrient environments. After 2000 generations, the 12 derived genotypes had diverged into at least six distinct phenotypic classes. The nutrients were classified into four groups based upon their uptake physiology. All 12 derived genotypes improved in fitness by similar amounts in the glucose environment, and this pattern of parallel fitness gains was also seen in those novel environments where the limiting nutrient shared uptake mechanisms with glucose. Fitness showed little or no consistent improvement, but much greater genetic variation, in novel environments where the limiting nutrient differed from glucose in its uptake mechanisms. This pattern of fitness variation in the novel nutrient environments suggests that the independently derived genotypes adapted to the glucose environment by similar, but not identical, changes in the physiological mechanisms for moving glucose across both the inner and outer membranes.


2021 ◽  
Vol 22 (9) ◽  
pp. 4315
Author(s):  
Marta Puchta ◽  
Jolanta Groszyk ◽  
Magdalena Małecka ◽  
Marek D. Koter ◽  
Maciej Niedzielski ◽  
...  

Seed aging is a complex biological process that has been attracting scientists’ attention for many years. High-throughput small RNA sequencing was applied to examine microRNAs contribution in barley seeds senescence. Unique samples of seeds that, despite having the same genetic makeup, differed in viability after over 45 years of storage in a dry state were investigated. In total, 61 known and 81 novel miRNA were identified in dry seeds. The highest level of expression was found in four conserved miRNA families, i.e., miR159, miR156, miR166, and miR168. However, the most astonishing result was the lack of significant differences in the level of almost all miRNAs in seed samples with significantly different viability. This result reveals that miRNAs in dry seeds are extremely stable. This is also the first identified RNA fraction that is not deteriorating along with the loss of seed viability. Moreover, the novel miRNA hvu-new41, with higher expression in seeds with the lowest viability as detected by RT-qPCR, has the potential to become an indicator of the decreasing viability of seeds during storage in a dry state.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Hiromichi Ueno ◽  
Tetsu Miyamoto ◽  
Hiroyuki Morimoto ◽  
Kenya Sanada ◽  
Ikutaro Furuno ◽  
...  

Abstract Background In order to facilitate the safe and long-term delivery of peritoneal dialysis (PD), it is necessary to improve the biocompatibility of peritoneal dialysis fluids (PDFs). The novel bicarbonate/lactate-buffered neutral PDFs (B/L-PDFs) are expected to be improved biocompatible. This study evaluated the biocompatibility of B/L-PDFs by analysis on the profile of angiogenesis-related proteins in drained dialysate of patients undergoing PD. Methods Concentrations of 20 angiogenesis-related proteins in the dialysate were semi-quantitatively determined using a RayBio® Human Angiogenesis Antibody Array and were compared between B/L-PDFs and conventional lactate-buffered neutral PDFs (L-PDFs). Results The expression of growth-related oncogene (GRO α/β/γ), which belongs to the CXC chemokine family, decreased significantly after use of the B/L-PDFs compared to the L-PDFs (P = 0.03). The number of the proteins with lower level in the B/L-PDFs compared with L-PDFs was significantly negatively correlated with the PD duration (Spearman ρ = − 0.81, P = 0.004). Conclusion This study suggested that B/L-PDFs are more biocompatible than conventional PDFs.


2015 ◽  
Vol 8 (10) ◽  
pp. 4487-4505 ◽  
Author(s):  
K.-L. Chang ◽  
S. Guillas ◽  
V. E. Fioletov

Abstract. Total column ozone variations estimated using ground-based stations provide important independent source of information in addition to satellite-based estimates. This estimation has been vigorously challenged by data inhomogeneity in time and by the irregularity of the spatial distribution of stations, as well as by interruptions in observation records. Furthermore, some stations have calibration issues and thus observations may drift. In this paper we compare the spatial interpolation of ozone levels using the novel stochastic partial differential equation (SPDE) approach with the covariance-based kriging. We show how these new spatial predictions are more accurate, less uncertain and more robust. We construct long-term zonal means to investigate the robustness against the absence of measurements at some stations as well as instruments drifts. We conclude that time series analyzes can benefit from the SPDE approach compared to the covariance-based kriging when stations are missing, but the positive impact of the technique is less pronounced in the case of drifts.


2017 ◽  
Author(s):  
Michaela Knoll ◽  
Ines Borrione ◽  
Heinz-Volker Fiekas ◽  
Andreas Funk ◽  
Michael P. Hemming ◽  
...  

Abstract. In the mainframe of the REP14-MED sea trial in June 2014, the hydrography and circulation west of Sardinia, observed by means of gliders, shipborne CTD instruments, towed devices, and vessel-mounted ADCPs, are presented and compared with previous knowledge. So far, the circulation is not well known in this area, and the hydrography is subject to long-term changes. Potential temperature, salinity, and potential density ranges, as well as core values of the observed water masses were determined. Modified Atlantic Water (MAW), with potential density anomalies below 28.72 kg m−3, showed a salinity minimum of 37.93 at 50 dbar. Levantine Intermediate Water (LIW), with a salinity maximum of about 38.70 at 400 dbar, was observed within a range of 28.72 < σΘ [kg m−3] < 29.10. MAW and LIW showed slightly higher salinities than previous investigations. During the trial, LIW covered the whole area from the Sardinian shelf to 7°15' E. Only north of 40° N was it tied to the continental slope. Within the MAW, a cold and saline anticyclonic eddy was observed in the southern trial area. The strongest variability in temperature and salinity appeared around this eddy, and in the southwestern part of the domain, where unusually low saline surface water entered the area towards the end of the experiment. An anticyclonic eddy of Winter Intermediate Water was recorded moving northward at 0.014 m s−1. Geostrophic currents and water mass transports calculated across zonal and meridional transects showed a good agreement with vessel-mounted ADCP measurements. Within the MAW, northward currents were observed over the shelf and offshore, while a southward transport of about 1.5 Sv occurred over the slope. A net northward transport of 0.38 Sv across the southern transect decreased to zero in the north. Within the LIW, northward transport of 0.6 Sv across the southern transects were mainly observed offshore, and decreased to 0.3 Sv in the north where they were primarily located over the slope. This presentation of the REP14-MED observations helps to further understand the long-term evolution of hydrography and circulation in the Western Mediterranean, where considerable changes occurred after the Eastern Mediterranean Transient and the Western Mediterranean Transition.


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