Comparative Analysis of Lithium First Wall Concepts for Tokamak with Reactor Technologies

When developing the stationary fusion reactor, an unresolved issue is the design of its intra-chamber plasma-facing elements. It has now become obvious that among the materials conventionally used for intra-chamber elements, there are no solid structural materials that would meet the requirements for the long-term operation under the effect of the flux of fusion neutrons (14 MeV) with a density of ~1014 cm–2 s–1 and the heat flux with a power density of 10–20 MW/m2. An alternative solution to this problem is the use of liquid metals as a plasma-facing materials, and, first of all, the use of lithium, which has a low atomic number (low charge number Z). Other easily-melting metals are also considered, which have higher Z number, but lower saturation vapor pressure than lithium. This will make it possible to create the long-lived, heavy-to-damage and self-renewing surface of the intra-chamber elements, which will not contaminate the plasma. The main ideas of the alternative concept of the intra-chamber elements can be formulated based on the comprehensive analysis of the problems and requirements arising during the development of intra-chamber elements of the stationary reactor, for example, the DEMO-type reactor. The article presents the analysis of the possible design of the lithium-coated intra-chamber elements and discusses the main ideas of the lithium first wall concept for the tokamak with reactor technologies.

Metabolite profiling and antioxidant capacity of lettuce Lactuca sativa var. longifolia grown in aquaponic system irrigated with shrimp effluents

This paper focuses on the quality of lettuce var. longifolia grown with shrimp effluents from well water (WW), diluted seawater (DSW) and a hydroponic solution (HS). Results evidenced that WW and DSW effluents slightly decreased weight, foliage, and yield (5-9%) in plants compared to HS control. Furthermore, WW-lettuce showed a higher level of total phenolic compounds (~71%), flavonoids (~90%), and antioxidant capacity (0.7-3-folds) than HS-plants, mainly in the soluble fraction. WW-lettuce also showed a higher content of total soluble solids (~16%) and, a lower saturation of color, which correlated significantly (p <0.05) with chlorophyll a. WW-lettuce exhibited the highest concentrations of p-hydroxybenzoic, p-coumaric and ferulic acids, as well as quercetin 3-O-glucoside and quercetin 3-O-ramnoside. Whereas DSW-lettuce showed the highest levels of caffeic acid, isorhamnetin 3-O-glucoside, kaempferol 3-O-glucoside, kaempferol and quercetin. HS-lettuce showed a higher proline content than the lettuces from the other treatments. These results indicate that aquaponic lettuce culture with shrimp effluent from WW could be used as an alternative culture system to reduce land area requirements, decrease or eliminate the discharge and impact of shrimp effluents, and simultaneously improve the functional properties of lettuce.

Suppression of Luminance Contrast Sensitivity by Weak Color Presentation

The results of psychophysical studies suggest that color in a visual scene affects luminance contrast perception. In our brain imaging studies we have found evidence of an effect of chromatic information on luminance information. The dependency of saturation on brain activity in the visual cortices was measured by functional magnetic resonance imaging (fMRI) while the subjects were observing visual stimuli consisting of colored patches of various hues manipulated in saturation (Chroma value in the Munsell color system) on an achromatic background. The results indicate that the patches suppressed luminance driven brain activity. Furthermore, the suppression was stronger rather than weaker for patches with lower saturation colors, although suppression was absent when gray patches were presented instead of colored patches. We also measured brain activity while the subjects observed only the patches (on a uniformly black background) and confirmed that the colored patches alone did not give rise to differences in brain activity for different Chroma values. The chromatic information affects the luminance information in V1, since the effect was observed in early visual cortices (V2 and V3) and the ventral pathway (hV4), as well as in the dorsal pathway (V3A/B). In addition, we conducted a psychophysical experiment in which the ability to discriminate luminance contrast on a grating was measured. Discrimination was worse when weak (less saturated) colored patches were attached to the grating than when strong (saturated) colored patches or achromatic patches were attached. The results of both the fMRI and psychophysical experiments were consistent in that the effects of color were greater in the conditions with low saturation colors.

An Experimental Approach to Assessing the Roles of Magnesium, Calcium, and Carbonate Ratios in Marine Carbonates

Marine biomineralization is a globally important biological and geochemical process. Understanding the mechanisms controlling the precipitation of calcium carbonate [CaCO3] within the calcifying fluid of marine organisms, such as corals, crustose coralline algae, and foraminifera, presents one of the most elusive, yet relevant areas of biomineralization research, due to the often-impenetrable ability to measure the process in situ. The precipitation of CaCO3 is assumed to be largely controlled by the saturation state [Ω] of the extracellular calcifying fluid. In this study, we mimicked the typical pH and Ω known for the calcifying fluid in corals, while varying the magnesium, calcium, and carbonate concentrations in six chemo-static growth experiments, thereby mimicking various dissolved inorganic carbon concentration mechanisms and ionic movement into the extracellular calcifying fluid. Reduced mineralization and varied CaCO3 morphologies highlight the inhibiting effect of magnesium regardless of pH and Ω and suggests the importance of strong magnesium removal or calcium concentration mechanisms. In respect to ocean acidification studies, this could allow an explanation for why specific marine calcifiers respond differently to lower saturation states.

The influence of rates of drying and wetting on measurements of soil water retention curves

The water retention curve is fundamental for a comprehensive description of the hydro-mechanical behaviour of unsaturated soils. The water retention testing system developed at Durham University allows direct and continuous measurement of suction using a high capacity tensiometer, water content determined from mass readings of a digital balance and measurements of volume change. The system was modified to accommodate an additional tensiometer to measure suction at the top besides the existing one at the bottom of the soil specimen. Soil specimens were subjected to drying and wetting following two procedures: discrete measurements carried out in stages to ensure equalisation and continuous measurement at different rates. All suctions measured during continuous and discrete measurements were very close at high saturation degrees. At lower saturation degrees, the suction values from the top and bottom of the specimen deviated from suctions observed in discrete measurements. This deviation in suction values was more evident in accelerated drying and wetting patterns. This can be explained by the fact that water permeability reduces with the decrease in saturation levels.

Poole–Frenkel Emission Saturation and Its Effects on Time-to-Failure in Ta-Ta2O5-MnO2 Capacitors

I-V characterization of Ta-Ta2O5-MnO2 capacitors was investigated at different temperatures, and Poole–Frenkel (PF) emission saturation was experimentally observed. Under the saturation voltage, the I-V curves at different temperature converged, and the temperature dependency was vanished. Above the saturation voltage, the leakage current was decreasing as the temperature increased. In order to evaluate the effects of saturation voltages (VS) on time-to-failure (TTF) of the capacitors, VS were first determined at +2°C and +25°C, then voltage accelerating tests were conducted at 85°C under 1.6 times of rated voltage. The distribution of VS and TTF of the samples were plotted and compared. It was shown that samples with lower saturation voltage failed earlier in the distribution of time-dependent dielectric breakdown. Comparing conventional methods for evaluating the quality of tantalum capacitors by measuring the leakage current at elevated temperature, the nondestructive measurement of saturation voltage at +2°C and +25°C may provide a novel and practicing approach tool to screening out capacitors with defected Ta2O5 layers.

Baseline Lighter Sleep and Lower Saturation Are Associated With Improved Sleepiness and Adherence on Continuous Rather Than Autotitrating Positive Airway Pressure

The objective was to test whether there were better outcomes on switching from autotitrating positive airway pressure (APAP) to continuous positive airway pressure (CPAP) in a clinic sample of patients with obstructive sleep apnea (OSA). Patients prescribed APAP in 2015-2016 and belonging to a subset characterized by side effects, or suboptimal response or adherence, were advised a switch to CPAP following a CPAP titration polysomnography. The main analysis was for improvement (after switch from APAP to CPAP) in (1) sleepiness, wakefulness inability, and fatigue, using change from baseline in the Sleepiness–Wakefulness Inability and Fatigue Test (delta SWIFT), and Epworth Sleepiness Scale (delta ESS), and (2) adherence using percentage of days with ≥4-hour use and whether there was ≥4-hour use on ≥70% days. To determine possible predictors for switching, additional analysis was performed for differences at baseline between patients switching and those staying on APAP. A total of 148 patients were switched from APAP to CPAP and had greater improvement in delta SWIFT (5.2 vs 4.1, P = .004), greater improvement in delta ESS (3.6 vs 2.9, P = .011), and better adherence (79.4% vs 74.3%, P = .006) on CPAP than on APAP. More patients were adherent on CPAP than on APAP (83.1% vs 68.9%, P = .006). Patients switching had higher baseline arousal index and stage N1 sleep, and lower nadir oxygen saturation, than 96 patients not switching. Thus, there is a subset of patients with better outcomes after switching to CPAP than on APAP. Patients with baseline lighter sleep (indicated by more arousals and stage N1), or greater desaturation, may be more likely to do better on CPAP than on APAP. CPAP may be the preferable treatment in a significant subset of patients. If APAP is used first anyway, side effects, or suboptimal response or adherence, should lead to consideration of switching to CPAP based on a CPAP titration polysomnography.

Research Progresses of Flash Evaporation in Aerospace Applications

Liquid is overheated and evaporated quickly when it enters into the environment with lower saturation pressure than that corresponding to its initial temperature. This phenomenon is known as the flash evaporation. A natural low-pressure environment and flash evaporation have unique characteristics and superiority in high altitude and outer space. Therefore, flash evaporation is widely used in aerospace. In this paper, spray flash evaporation and jet flash evaporation which are two different forms were introduced. Later, key attentions were paid to applications of flash evaporation in aerospace. For example, the flash evaporation has been used in the thermal control system of an aircraft and the propelling system of a microsatellite and oil supply system of a rocket motor. Finally, the latest progresses in the calculation model and numerical simulation of flash evaporation were elaborated.

Comparison of oxygen saturation range on the basis of mode of delivery in term new-borns: an observational study

Background: All newborns are cyanotic immediately after birth. Gradually within next few minutes of life this saturation increases and reaches target level in approximately 10 minutes. But the saturation range differs on the basis of amount of stress a neonate develops while being delivered out of mother’s womb.Methods: A total of 215 term healthy neonates were included out of which 131 were delivered vaginally and 84 were delivered via cesarean section (elective or emergency). Relevant antenatal history was taken and noted. Pulse oximetry readings were recorded continuously by using Masimo rad 5 pulse oximeter with signal extraction technology (SET) for first 10 minutes of life in all neonates.Results: At 1min of life spo2 of vaginal delivered babies was 70%(66% -73%) compared to cesarean delivered babies being 62%(57%-69%) with a highly significant p value (<0.001). Similarly, at 5 min the SpO2 was 89 % (85%-91%) and 80% (78%-82%) in normal vaginal delivered and cesarean section babies respectively. At 10 min of life when SpO2 measured in both groups the saturation difference was less but still significant.Conclusions: all neonates at birth are cyanotic and have a lower saturation which increases gradually with time. Ceserian delivered neonates have a low saturation range as compared to vaginal delivered newborn.