Gravity Wave Ducting Observed in the Mesosphere Over Jicamarca, Peru

Short-period gravity waves are ubiquitous in the mesosphere, but the vertical structures of their perturbations are difficult to observe. The Jicamarca 50-MHz very high frequency radar allows observations of winds and turbulent scatter with high temporal and vertical resolution. We present a case of a quasi-monochromatic gravity wave with period 520 (±40) s that is likely ducted below a southward wind jet between 68 and 74 km. Above this layer of evanescence, a northward wind enables it to emerge into a more stable layer, where it is refracted to a short vertical wavelength of 2.2 (±0.2) km; data show evidence of weak nonlinearity, and possible overturning or partial reflection from higher altitudes, above the observable region, in the form of a standing wave structure in vertical velocity at approximately 75 km. Based on the dispersion relation, and with help of a two-dimensional model, we determine that most likely the wave is propagating northward and is being ducted below and tunneling through the regions of evanescence created by the wind flow and typical mesospheric thermal structure. This is the first time that such an event has been identified in the Jicamarca mesospheric echoes, and it is distinct from Kelvin-Helmholtz billows also commonly seen with this sensitive radar—instead apparently revealing tunneling of the gravity wave through ambient winds

Methodology for Finding Maximum Performance and Improvement Possibility of Rule-Based Control for Parallel Type-2 Hybrid Electric Vehicles

Hybrid electric vehicles (HEVs) require supervisory controllers to distribute the propulsion power from sources like an engine and motors. Control concepts based on optimal control theories such as dynamic programming (DP) and Pontryagin’s minimum principle (PMP) have been studied to maximize fuel efficiencies. These concepts are, however, not practical for real-world applications because they guarantee optimality only if future driving information is given prior to the actual driving. Instead, heuristic rule-based control concepts are widely used in real-world applications. Those concepts are not only simple enough to be designed based on existing vehicle control concepts, but also allow developers to easily intervene in the control to enhance other vital aspects of real-world vehicle performances, such as safety and drivability. In this study, a rule-based control for parallel type-2 HEVs is developed based on representative control concepts of real-world HEVs, and optimal control parameters are determined by optimization processes. The performance of the optimized rule-based control is evaluated by comparing it with the optimal results obtained by PMP, and it shows that the rule-based concepts can achieve high fuel efficiencies, which are close, typically within 4%, to the maximum values obtained by PMP

Efficient Nitrogen Removal of Reject Water Generated from Anaerobic Digester Treating Sewage Sludge and Livestock Manure by Combining Anammox and Autotrophic Sulfur Denitrification Processes

The reject water from anaerobic digestion with high (Total Nitrogen) TN concentration was treated by a demonstration plant combining the anammox process and SOD (SOD®; Sulfur Oxidation Denitrification) process. The anaerobic digestion was a co-digestion of livestock wastewater, food waste water, and sewage sludge so that the TN concentration and conductivity of the reject water were very high. This anammox plant was the first anammox demonstration plant in South Korea. The maximum TN removal efficiency of 80% was achieved for the anammox reactor under nitrogen loading rate (NLR) of 0.45 kg-N/m3·d. As a result of decreasing the dilution of the reject water, the influent conductivity and NLR values were increased to 7.8 mS/cm and 0.7 kg/m3·d, causing a rapid decrease in the TN removal efficiency. The sludge concentration from the hydro-cyclone overflow was about 40 mg-MLVSS/L in which small sized anammox granules were detected. It was proven that the increase in (Mixed Liquor Volatile Suspended Solids) MLVSS concentration in the anammox reactor was not easy under high influent conductivity and NLR. 97% of NO2−-N+NO3−-N generated from the anammox process could be treated successfully by the SOD reactor. A TN removal efficiency of 35% under poor annamox treatment could increase to 67% by applying the SOD reactor post treatment for the removal of NO3−-N. The dominant anammox bacteria in the anammox reactor was identified as Brocadia fulgida and 9.3% (genus level) of the bacteria out of the total bacteria were anammox bacteria

Dropwise condensation induced on chromium ion implanted aluminum surface

Aluminum substrates are irradiated with chromium ions and the steam condensation heat transfer performance on these surfaces is examined. Filmwise condensation is induced on the surface of aluminum specimens irradiated with chromium ion dose of less than 1016 ions/cm2 while dropwise condensation occurs on the specimens irradiated with chromium ion dose of 5 × 1016 ions/cm2 in the range of ion energy from 70 to 100 keV. The heat transfer coefficient of the surfaces on which dropwise condensation occurs appeared to be approximately twice as much as the prediction by Nusselt’s film theory. In a durability test, dropwise condensation lasts over six months and the heat transfer coefficient is also maintained. Keywords: Dropwise condensation, Filmwise condensation, Chromium, Ion implantation, Durabilit

Topography and Anatomical Variations of the Axillary Artery

Knowledge of anatomical variations of the limb’s main arteries is significant for the clinicians. Thus, this study is aimed at examining the branching pattern and anatomical variations of the axillary artery. We conducted research on 59 upper limbs of adult human donated cadavers. All axillary artery branches’ origins were assessed, and the correlations between points of origins and variations of specific branches were evaluated. The average length of the axillary artery was found to be 11.22 cm, and this length was defined as reference line. Based on this reference line, the first, second, and third parts were 37.56%, 39%, and 30.05%, respectively. The STA was originated from 25.11%. The TAA and LTA were 42.67% and 54.82%, respectively. The SSA, ACHA, and PCHA were 64.72%, 83.89%, and 84.53%, respectively. The origin of LTA was correlated with that of SSA (R=0.473, P<0.05) and AHCA (R=0.307, P<0.05), respectively. And there was a positive correlation between AHCA and PHCA (R=0.705, P<0.05). The number of branches ranged from 3~6, and 9 types were shown. The most frequent branching pattern was common origin of the LTA and SSA (22/59). And AHCA and PHCA were originated together in 19 cases, and both patterns were combined in 12 cases. TTA and LTA branched together in 9 cases, and common trunk for the SSA, PHCA, and AHCA was found in 2 cases. According to this pattern, the origin of LTA and PCHA was significantly different. This information is particularly useful for surgeons and clinicians

Recent Advances in Patterning Strategies for Full-Color Perovskite Light-Emitting Diodes

Highlights This article reviews the recent progress in the patterning techniques of metal halide perovskites for full-color displays. Patterning techniques of perovskites are subdivided into in situ crystallization and patterning of colloidal perovskite nanocrystals, including photolithography, inkjet printing, thermal evaporation, laser ablation, transfer printing, and so on. The strength and weakness of each patterning methods are discussed in detail from the viewpoint of their applications in full-color displays