Vertical Cross-section Research Articles

Identifikasi Sebaran Asap Kebakaran Hutan di Wilayah Jambi dengan Menggunakan Radar C-BAND

Forest and land fires along with the distribution of smoke are one of the disasters threats in the Jambi region which has tropical forests. By knowing the lowest level of visibility from observations, this study was conducted on September 23, 2015. Weather and satellite radar have ability to detect particles and the distribution of smoke from forest and land fires with great spatial and temporal resolution, supported by HIMAWARI-8 satellite data as comparison. C-Band Doppler radar and default strategy scanning are used to identify smoke in Jambi. Wind layer analysis uses CAPPI V products to display smoke distribution and CMAX dBZ with palette changes to identify smoke particles, which then will be carried out vertical cross section to see smoke reflectivity values, identify smoke vertical profiles, and patterns of smoke distribution of forest and land fires. The smoke reflectivity index value can be seen from the dBZ value. The results of the identification show that the smoke material reaches a maximum reflectivity value of 30 dBZ at the centre of the fire point and the minimum value of very fine smoke particles reaches -24.4 dBZ which scattered with the dominant velocity distribution direction to the northwest.

Analysis of a multiple non-supercell tornado event in Mexico

Multiple tornado events frequently occur in different parts of the world. A region that seems favorable for recurring multiple tornado events due to its geographical location and topography is the eastern sector of the Trans-Mexican Volcanic Belt. A notable multiple tornado event that occurred in this region is investigated. It consisted of five simultaneous tornadoes during the convergence of three air masses: a cold air mass displaced from the north with moderately high relative humidity and specific humidity, a comparatively warm air mass with moderate relative humidity from the southeast, and a hotter air mass with low relative humidity from the southwest. This situation generated a line of intense horizontal wind shear through which the five tornadoes occurred. Numerical simulations revealed three cyclonic vortices and other minor disturbances along the shear line. Vertical cross-sections show rising air in these disturbances suggesting a cyclonic character. The results indicate that the relatively warm mass from the southeast moves over the one associated with a cold front coming from the north, generating multiple cyclonic rotation zones. Experiments with Lagrangian particles revealed vertical movements in the cyclonic rotation zones implying that the maximum heights of the tornadoes varied between 1000 and 1500 m. Moisture flux convergence calculations display structures resembling Kelvin-Helmholtz instabilities. This research proposes a conceptual model where the convergence of masses induced by topography can lead to multiple tornado generation.

Poster 124: Elevated Lipid Metabolites in Stored Clinical OCA Media are Associated with Chondrocyte Death

Objectives: A major limitation of osteochondral allografts (OCA) is the deterioration of cartilage health associated with cell death during prolonged storage. It is well established that chondrocyte viability in OCA is a critical factor for repair and clinical outcomes, but little is known about the mechanisms that contribute to chondrocyte death during storage. Elevated bioactive lipid metabolites and free fatty acids (FFAs) have been associated with cell death and tissue damage for various pathologies through lipotoxicity. However, the levels and effect of FFA accumulation in OCA media during prolonged storage are unknown. The purpose of this study was to determine if bioactive lipid metabolites accumulate in the storage media of OCA and are associated with a loss of chondrocyte viability during prolonged storage. We hypothesized that FFAs will accumulate over time in the storage media of OCA and adversely impact cartilage health during storage. Methods: To elucidate potential mechanisms of cartilage health decline during storage, 21 fresh human hemi-condyle osteochondral allograft tissues and media provided by a US tissue bank were analyzed after 7, 28, and 68 days of prolonged cold storage. Targeted metabolomics analysis measured bioactive FFAs, and primary (lipid hydroperoxide, ROOH) and secondary (malondialdehyde, MDA) lipid oxidation products. Chondrocyte viability was measured using standard LIVE/DEAD assay and confocal microscopy. Results: All fatty acid metabolites in storage media significantly increased with increased storage time (Figure 1; p<0.05). ROOH was significantly higher at Day 28 of storage. No difference in secondary lipid hydroperoxide products in storage media were observed. Chondrocyte viability significantly declined in both the en face and vertical cross-section analysis with increased storage time (Figure 2) and inversely correlated with fatty acid metabolites (Figure 3; p<0.05). Conclusions: It is well established that elevated levels of certain free fatty acids and lipid oxidation products can alter cell function and cause cell death through lipotoxicity and other mechanisms. This work is the first to identify elevated levels of FFA metabolites and primary oxidation lipid product in the storage media from clinical OCA. The concentrations of FFA metabolites were measured at levels (>100µM) known to induce cell death and were directly correlated with chondrocyte viability. These findings provide important targets for understanding why cartilage health declines during storage to better optimize media formulations and improve graft health.

Modeling Multi-Rotunda Buildings at LoD3 Level from LiDAR Data

The development of autonomous navigation systems requires digital building models at the LoD3 level. Buildings with atypically shaped features, such as turrets, domes, and chimneys, should be selected as landmark objects in these systems. The aim of this study was to develop a method that automatically transforms segmented LiDAR (Light Detection And Ranging) point cloud to create such landmark building models. A detailed solution was developed for selected buildings that are solids of revolution. The algorithm relies on new methods for determining building axes and cross-sections. To handle the gaps in vertical cross-sections due to the absence of continuous measurement data, a new strategy for filling these gaps was proposed based on their automatic interpretation. In addition, potential points associated with building ornaments were used to improve the model. The results were presented in different stages of the modeling process in graphic models and in a matrix recording. Our work demonstrates that complicated buildings can be represented with a light and regular data structure. Further investigations are needed to estimate the constructed building model with vectorial models.

Antarctic atmospheric Richardson number from radiosonde measurements and AMPS

Abstract. Monitoring a wide range of atmospheric turbulence over the Antarctic continent is still tricky, while the atmospheric Richardson number (Ri; a valuable parameter which determines the possibility that turbulence could be triggered) is easier to obtain. The Antarctic atmospheric Ri, calculated from the potential temperature and wind speed, was investigated using the daily results from the radiosoundings and forecasts of the Antarctic Mesoscale Prediction System (AMPS). Radiosoundings for a year at three sites (McMurdo – MM, South Pole – SP, and Dome C – DC) were used to quantify the reliability of the AMPS forecasts. The AMPS-forecasted Ri can identify the main spatiotemporal characteristics of atmospheric turbulence over the Antarctic region. The correlation coefficients (Rxy) of log 10(Ri) at McMurdo, the South Pole, and Dome C are 0.71, 0.59, and 0.53, respectively. The Ri was generally underestimated by the AMPS and the AMPS could better capture the trend of log 10(Ri) at relatively unstable atmospheric conditions. The seasonal median of log 10(Ri) along two vertical cross-sections of the AMPS forecasts are presented, and it shows some zones where atmospheric turbulence can be highly triggered in Antarctica. The Ri distributions appear to be reasonably correlated to some large-scale phenomena or local-scale dynamics (katabatic winds, polar vortices, convection, gravity wave, etc.) over the Antarctic plateau and surrounding ocean. Finally, the log 10(Ri) at the planetary boundary layer height (PBLH) were calculated and their median value is 0.316. This median value, in turn, was used to estimate the PBLH and agrees well with the AMPS-forecasted PBLH (Rxy>0.69). Overall, our results suggest that the Ri estimated by AMPS are reasonable and the turbulence conditions in Antarctica are well revealed.

Extracting the 3D spatial structure of soil cracks in the North China Plain from paraffin casting and exploring the developmental patterns of vertical cross-sectional morphology of the cracks

Cracking from soil desiccation is a common phenomenon. Understanding the structure of cracks is highly important in the research of soil moisture and heat transportation, as well as the strength of soil structure within soil. There is limited research on the three-dimensional (3D) spatial characteristics of soil desiccation cracks. Furthermore, the absence of a dependable and precise in-situ technique for extracting and digitizing the three-dimensional crack structure means that the commonly employed simplified crack models (such as V-shaped and cuboid-shaped) have received limited testing. This study examines the feasibility of extracting the 3D structure of cracks by combining in-situ paraffin casting in sandy loam soil of North China Plain with a 3D laser scanner. Parameters (length (L), width (W), depth (D), depth to width ratio (C)), as well as the vertical cross-section profile (W ∼ D) of each crack, were used to quantitatively describe the structure of cracks. Our study demonstrated that digitalized 3D cracks with 5 μm spatial resolution can be obtained quickly by paraffin infusion combined with a 3D laser scanner. Our result based on 18 crack cross-section profiles also demonstrates that W ∼ D do not follow either the V-shaped crack model or the cuboid-shaped crack model. All of the 18 normalized vertical profiles of cracks obey the power function relationship (R2 = 0.850) rather than the linear relationship of the V-shaped model (R2 = 0.794). The shape of the soil moisture profile is convex, which contradicts the concave profile of the observed vertical cracks. Even after combining the Soil Shrinkage Characteristic Curve (SSCC) with the soil moisture profile, we still failed to replicate the observed concave crack profile. The observed crack morphology in experiments can be replicated by both the elliptical model and the parabolic model of fracture mechanics, albeit with less predictive accuracy when compared to the power function model. This suggests that the current understanding of soil desiccation cracking in soil science is deficient, as it lacks appropriate methods and theoretical mechanisms for investigating soil cracking.

Ocean Temperature Observations in Hurricane Dorian (2019)

Abstract Upper-ocean temperatures from 72 airborne expendable bathythermographs (AXBTs) collected during U.S. Air Force Hurricane Hunter flights into Hurricane Dorian (2019) over a 72-h period are examined. Three transects collected behind the storm reveal increased cross-track sea surface temperature gradient magnitudes as Dorian intensified to a category-5 hurricane and slowed while approaching the Bahamas. The cold wake, evident in vertical and horizontal cross sections from in situ and satellite sensors, appears as an expected response to tropical cyclone passage. Atypical, however, is the 2°C surface cooling observed over 36 h in a pair of transects ahead of hurricane force winds in Dorian, likely due to changes in the tropical cyclone’s translation speed and direction and/or proximity to the Gulf Stream and continental shelf. Collocated AXBT pairs document a dynamical regime shift from mixing to upwelling as Dorian slows and turns. Relationships between time-integrated wind stress and sea surface temperature indicate track-relative differences varying with storm translation speed and heading changes, paralleling the shift in cooling dynamics. Significance Statement We studied in situ and satellite ocean temperature observations beneath Hurricane Dorian (2019) as the storm moved slowly, turned north, and weakened near Grand Bahama Island. We found a distinct change in the spatial distribution of cool upper-ocean temperatures beneath the storm, which indicated a shift in the primary cooling mechanism from ocean mixing to upwelling. This mechanism shift is important because hurricanes depend on warm ocean temperatures for energy, and upwelling roughly doubles the area of cooling beneath the storm. Our results highlight the effects of large heading changes on the upper-ocean response beneath tropical cyclones, especially in tandem with slow translation speeds.

Almost-Hermitian random matrices and bandlimited point processes

We study the distribution of eigenvalues of almost-Hermitian random matrices associated with the classical Gaussian and Laguerre unitary ensembles. In the almost-Hermitian setting, which was pioneered by Fyodorov, Khoruzhenko and Sommers in the case of GUE, the eigenvalues are not confined to the real axis, but instead have imaginary parts which vary within a narrow “band” about the real line, of height proportional to tfrac{1}{N}, where N denotes the size of the matrices. We study vertical cross-sections of the 1-point density as well as microscopic scaling limits, and we compare with other results which have appeared in the literature in recent years. Our approach uses Ward’s equation and a property which we call “cross-section convergence”, which relates the large-N limit of the cross-sections of the density of eigenvalues with the equilibrium density for the corresponding Hermitian ensemble: the semi-circle law for GUE and the Marchenko–Pastur law for LUE. As an application of our approach, we prove the bulk universality of the almost-circular ensembles.

Experimental and numerical investigation on non-premixed CH4/air combustion in a micro Swiss-roll combustor

This paper reports the experimental investigation and numerical analysis of the non-premixed CH4/air combustion in a micro Swiss-roll combustor. Six flame patterns were observed in the experiment, namely, single flame, twin flames, pulsating flame, obviously asymmetric flame, extinction and blow-off. A global map is drawn for these combustion regimes based on systematic experimental observation. The lower combustible limits of the nominal equivalence ratio (ϕ) and inlet methane flow rate (FM) are 0.4 and 0.02 L/min, respectively. Moreover, the blow-off limit increases significantly as the equivalence ratio is increased from 0.7 to 0.8. Furthermore, it is found that both the maximum and average surface temperature of the combustor cover show a non-monotonic variation versus the nominal equivalence ratio, and their maximum and minimum values appear at ϕ = 0.9 and 0.8, respectively. Numerical simulation can reproduce the flame shapes successfully. In addition, the asymmetric flame structures in the vertical direction were also discovered through numerical simulation. The comparative analysis demonstrates that the buoyancy effect leads to asymmetric flow field in the vertical cross section of the combustor. As a result, the reaction heat and fuel conversion ratio in the combustion chambers change non-monotonically with the equivalence ratio, which leads to a similar variation manner of the surface temperature. In summary, the present study provides a deep insight into the characteristics of non-premixed combustion in micro Swiss-roll combustors.

Self-Potential as a Tool to Monitor Redox Reactions at an Ore Body: A Sandbox Experiment

Ore bodies generate natural electrical fields that are measurable at the ground surface. The ground surface signature of this electrical field is called a self-potential anomaly. We developed a sandbox experiment to monitor the evolution of a self-potential anomaly associated with redox processes mediated by bacterial activity at the surface of a buried metallic object crossing the water table. A Bio-Electrochemical Cell (BEC) is formed by a metal bar connecting the upper, oxygen-rich, part of the tank and an aquifer containing an electron donor in the form of acetate. The self-potential response was observed during a period of 327 days. The tomography of the self-potential signature confirms that self-potential tomography is able to locate the metallic target acting as a BEC. In addition, we performed redox potential, pH, and electrical potential measurements over a vertical cross-section of the tank at several time steps to obtain an idea of where the redox front is located. The distributions of the redox potential and pH further demonstrated the development of the oxidation-reduction chemical processes facilitated by the BEC as bacterial communities developed around the metallic bar. The electrical potential anomaly shows that the bacterial communities followed a short period of exponential growth, then a longer period of a sustained population. These results demonstrate the usefulness of the self-potential method in monitoring redox processes at the surface of a buried ore body. Further works will need to combine such self-potential anomalies with induced polarization anomalies through joint inversion.

Optical Anisotropy and Dimple Formation on Films Formed after Drying of Gelatinized Starch Solution Droplets.

We study the microstructures in the drying droplets of gelatinized starch solutions on a flat substrate. Cryogenic scanning electron microscopy studies on the vertical cross-section of these drying droplets for the first time reveal a relatively thinner solid elastic crust of uniform thickness at the free surface, an intermediate mesh region below the crust, and an inner core of a cellular network structure made of starch nanoparticles. We find that the deposited circular films formed after drying are birefringent and azimuthally symmetric with a dimple at their center. We propose that the dimple formation in our sample occurs due to the evaporation-induced stress on the gel network structure in the drying droplet. The polarizing optical microscopic studies show that these films are optically uniaxial at their center and increasingly biaxial away from the center.

Study on Complex Wake Characteristics of Yawed Wind Turbine Using Actuator Line Method

In modern large-scale wind farms, power loss caused by the wake effect is more than 30%, and active yaw control can greatly reduce the influence of the wake effect by deflecting the wind turbine’s wake. The yawed wind turbine’s wake characteristics are complex, and a deep comprehension of a yawed turbine’s wake is necessary. The actuator line method combined with URANS (unsteady Reynold-averaged Navier–Stokes equations) is used to study the yawed wind turbine’s wake characteristics in this paper. Compared with an un-yawed wind turbine, a yawed one has two main characteristics, deflection and deformation. With an increasing yaw angle, turbine wake shows an increasing deflection. The results indicated that deflection at different height was different, the wake profile showed the biggest deflection at about the hub height, while the smallest deflection existed at the top and bottom of the yawed turbine’s wake. This can be visually demonstrated by the evolution of a kidney-shape velocity distribution at the vertical cross-section. Two-dimensional and three-dimensional presentations of velocity deficit distributions are presented in this paper. The evolution of an irregular kidney-shape distribution is discussed in this paper. It is formed by the momentum exchange caused by the counter-rotating vortex pair. The results indicated that the counter-rotating vortex pair was composed of the streamwise vortex flux brought by the tip vortex. Furthermore, when the wind turbine rotated clockwise and yawed clockwise, the negative vorticity of counter-rotating vortex first appeared in the upper left position.

Gravity Waves Emitted From Kelvin‐Helmholtz Instabilities

AbstractFritts, Wang, Lund, and Thorpe (2022, https://doi.org/10.1017/jfm.2021.1085) and Fritts, Wang, Thorpe, and Lund (2022, https://doi.org/10.1017/jfm.2021.1086) described a 3‐dimensional direct numerical simulation of interacting Kelvin‐Helmholtz instability (KHI) billows and resulting tube and knot (T&K) dynamics that arise at a stratified shear layer defined by an idealized, large‐amplitude inertia‐gravity wave. Using similar initial conditions, we performed a high‐resolution compressible simulation to explore the emission of GWs by these dynamics. The simulation confirms that such shear can induce strong KHI with large horizontal scales and billow depths that readily emit GWs having high frequencies, small horizontal wavelengths, and large vertical group velocities. The density‐weighted amplitudes of GWs reveal “fishbone” structures in vertical cross sections above and below the KHI source. Our results reveal that KHI, and their associated T&K dynamics, may be an important additional source of high‐frequency, small‐scale GWs at higher altitudes.

Feldspar traces mineralization processes in the Qongjiagang giant lithium ore district, Himalaya, Tibet

Recently, a large spodumene pegmatite deposit was discovered in the Higher Himalayan orogenic zone near Qongjiagang. The granites exposed on about 1500 vertical meters of the outcrop (with elevation varying from 4077 m to 5533 m) show an evolution from two-mica granite to tourmaline muscovite granite and tourmaline albite granite. Various types of pegmatites are dispersed throughout the granite, creating an opportunity to examine the evolutionary relationship between these rock types and their potential as ore deposits rich in lithium. This study collected feldspar samples from various granites and pegmatites along a vertical cross-section, and analyzed their structures using various techniques including Raman spectroscopy, and transmission electron microscopy. Elemental and isotopic compositions were determined using electron microprobe and laser ablation inductively coupled plasma mass spectrometry, providing valuable mineralogical information on the formation of widespread lithium deposits in the Qongjiagang area. The observed variations in feldspar composition suggest that changes in granite lithology and ore-bearing potential of pegmatites with increasing altitude result from upward fractional crystallization of magma formed by partial melting of Himalayan crystalline basement. This process is likely driven by decreasing temperature, resulting in a significant decrease in concentrations of alkaline earth metals (e.g., Ca, Sr, Ba), and gradual enrichment of trace elements including Rb, Cs, and Li. As a result, pegmatites attain a melt environment similar to that of the adjacent granite at similar elevations. Structural features of feldspar suggest that the decrease in Li concentration in K-feldspar and the formation of lithium-rich zonation of pegmatites are a result of simultaneous growth of spodumene and blocky orthoclase during the magmatic stage, as well as deuteric fluid extraction by syntectonic processes during the transition to the stable stage of microcline feldspar.

Transport pathways of carbon monoxide from Indonesian fire pollution to a subtropical high-altitude mountain site in the western North Pacific

Abstract. Dry conditions associated with the El Niño–Southern Oscillation (ENSO) and a positive Indian Ocean Dipole (IOD) are known to have caused major fire pollution events and intense carbon emissions over a vast spatial expanse of Indonesia in October 2006 and 2015. During these two events, a substantial increase in the carbon monoxide (CO) mixing ratio was detected by in situ measurements at Lulin Atmospheric Background Station (LABS; 23.47∘ N 120.87∘ E; 2862 ma.s.l.) in Taiwan, which is the only background station in the subtropical western North Pacific region. Compared to the long-term October mean (2006–2021), CO was elevated by ∼ 47.2 ppb (parts per billion; 37.2 %) and ∼ 36.7 ppb (28.9 %) in October 2006 and 2015, respectively. This study delineates plausible pathways for the CO transport from Indonesia to LABS using Measurement of Pollution in the Troposphere (MOPITT) CO observations and Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA-2) reanalysis products (winds and geopotential height – GpH). Two simultaneously occurring transport pathways were identified, namely (i) horizontal transport in the free troposphere and (ii) vertical transport through the Hadley circulation (HC). The GpH analysis of both events revealed the presence of a high-pressure anticyclone over the northern part of the South China Sea (SCS), which played an important role in the free-tropospheric horizontal transport of CO. In this scenario, CO in the free troposphere is transported on the western edge of the high-pressure system and then driven by subtropical westerlies to LABS. Simultaneously, uplifted CO over Indonesia can enter the HC and be transferred to subtropical locations such as LABS. The vertical cross section of the MOPITT CO and MERRA-2 vertical pressure velocity supported the transport of CO through the HC. Furthermore, the results revealed a distinct HC strength in two events (higher in 2006 compared to 2015) due to the different ENSO conditions. Overall, the present findings can provide some insights into understanding the regional transport of pollution over Southeast Asia and the role of climate conditions on transport pathways.

Using Excimer Laser for Manufacturing Stimuli Responsive Membranes.

A 248 nm KrF excimer laser can be used to manufacture temperature and pH-responsive polymer-based membranes for controlled transport applications. This is done by a two-step approach. In the first step, well-defined/shaped and orderly pores are created on commercially available polymer films by ablation by using an excimer laser. The same laser is used subsequently for energetic grafting and polymerization of a responsive hydrogel polymer inside the pores fabricated during the first step. Thus, these smart membranes allow controllable solute transport. In this paper, determination of appropriate laser parameters and grafting solution characteristics are illustrated to obtain the desired membrane performance. Fabrication of membranes with 600 nm to 25 μm pore sizes by using the laser through different metal mesh templates is discussed first. Laser fluence and the number of pulses need to be optimized to obtain the desired pore size. Mesh size and film thickness primarily control the pore sizes. Typically, pore size increases with increasing fluence and the number of pulses. Larger pores can be created by using higher fluence at a given laser energy. The vertical cross-section of the pores turns out to be inherently tapered due to the ablative action of the laser beam. The pores created by laser ablation can be grafted with PNIPAM hydrogel by using the same laser to perform a bottom-up grafting-from type pulsed laser polymerization (PLP) in order to achieve the desired transport function controlled by temperature. For this purpose, a set of laser frequencies and pulse numbers need to be determined to obtain the desired hydrogel grafting density and the extent of cross-linking, which ultimately provide controlled transport by smart gating. In other words, on-demand switchable solute release rates can be achieved by controlling the cross-linking level of the microporous PNIPAM network. The PLP process is extremely fast (few seconds) and provides higher water permeability above the lower critical solution temperature (LCST) of the hydrogel. Experiments have shown high mechanical integrity for these pore-filled membranes, which can sustain pressures up to 0.31 MPa. The monomer (NIPAM) and cross-linker (mBAAm) concentrations in the grafting solution need to be optimized in order to control the network growth inside the support membrane pores. The cross-linker concentration typically has a stronger effect on the temperature responsiveness. The pulsed laser polymerization process described can be extended to different unsaturated monomers, which can be polymerized by the free radical process. For example, poly(acrylic acid) can be the grafted to provide pH responsiveness to membranes. As for the effects of thickness, a decreasing trend is observed in the permeability coefficient with increasing thickness. Furthermore, the film thickness has little or no effect on PLP kinetics. The experimental results have shown that membranes manufactured by excimer laser are excellent choices for applications where flow uniformity is the prime requirement, as they possess uniform pore sizes and distribution.

Ocean Surface Gravity Wave Excitation of Flexural Gravity and Extensional Lamb Waves in Ice Shelves

Flexure and extension of ice shelves in response to incident ocean surface gravity waves have been linked to iceberg calving, rift growth, and even disintegration of ice shelves. Most modeling studies utilize a plate bending model for the ice, focusing exclusively on flexural gravity waves. Ross Ice shelf seismic data shows not only flexural gravity waves, with dominantly vertical displacements, but also extensional Lamb waves, which propagate much faster with dominantly horizontal displacements. Our objective is to model the full-wave response of ice shelves, including ocean compressibility, ice elasticity, and gravity. Our model is a 2D vertical cross-section of the ice shelf and sub-shelf ocean cavity. We quantify the frequency-dependent excitation of flexural gravity and extensional Lamb waves and provide a quantitative theory for extensional Lamb wave generation by the horizontal force imparted by pressure changes on the vertical ice shelf edge exerted by gravity waves. Our model predicts a horizontal to vertical displacement ratio that increases with decreasing frequency, with ratio equal to unity at ~0.001 Hz. Furthermore, in the very long period band (<0.003 Hz), tilt from flexural gravity waves provides an order of magnitude larger contribution to seismometer horizontal components than horizontal displacements from extensional Lamb waves.

Enlarged rete pegs with excessive accumulation of melanosomes leading to darker aging spots revealed by histomorphological measurements of internal structures of the epidermis.

Various histological studies of facial pigmented spot sites such as solar lentigo have been reported, but few studies have used quantitative indices by histomorphometric analysis of the internal structure of pigmented spot sites using non-invasive methods. In the present study, to quantitatively elucidate morphological changes in the epidermis in male, darker-pigmented spots and female, light-pigmented spots, indices that characterize the internal structure of the epidermis in pigmented spot sites were measured using in vivo confocal laser scanning microscopy (CLSM). The darkness of pigmented spots on the cheeks of 69 women and 43 men was analysed using image analysis software. The L* value was calculated from RGB values obtained from facial images. The internal structures of pigmented spots on the cheeks of 13 subjects were observed by CLSM. Various parameters were measured using CLSM images from the surface of the stratum corneum to the bottom of the dermal papillae, including the thickness of the epidermis, melanosome content, and shape of the dermal papillae. Mean ΔL* values between pigmented spots and non-pigmented areas of male subjects were significantly increased in the 40s and 50s compared with those of female subjects. Conspicuous pigmented spots increased in the 40s in male subjects and the 50s in female subjects. In CLSM observations, significant increases in the thickness of the epidermis and melanosome content were confirmed in pigmented spots compared with surrounding non-pigmented areas. In particular, melanosome content in the male subject group with dark-coloured pigmented spots increased significantly to about eight times that of non-pigmented areas, and more than double that of the male subject group with light-coloured pigmented spots. From the measurements of quantitative parameters, morphological changes in the epidermis were clearly related to the surface colour tone of pigmented spots. Darker pigmented spot sites tended to show longer rete pegs in the epidermis. Accumulation of melanosomes in epidermal basal cells could be considered to increase with the degree of elongation of rete pegs at pigmented spot sites and, thus, induce darker pigmented spots.

Comprehensive 3E analyses of a parabolic trough collector equipped with an innovative combined twisted turbulator

The Parabolic trough collector (PTC) is one of the most well-known equipment in renewable energy. Today, it is also a renewable source for refining and transferring power to a low-carbon economy. The present study aims to investigate the effect of the geometrical shape of the Receiver cross-section in the PTC and to investigate the effect of placing the innovative combined twisted turbulator (CTT) in it. The receiver is simulated with three different geometric shapes circular cross-section (CCS), vertical elliptical cross-section (VECS), and horizontal elliptical cross-section (HECS). The PTC contains a two-phase MWCNT-GO/Syltherm 800 hybrid nanofluid (HNF), simulated using the mixture model. In this study, numerical simulations have been conducted for Reynolds numbers (Re) of 5000 to 20,000, volume fractions (ϕ) of 1 and 2% of nanoparticles, and pitch ratios (PR) of 0.5 to 2 of the innovative CTT. The results obtained from the present study show that the geometrical change of the cross-section of the receiver is very effective in the hydrodynamic performance of the PTC. Also, placing the innovative CTT in Receiver has consistently increased thermal performance and energy efficiency. The performance evaluation criteria (PEC) index is always greater than 1 in all numerical simulation modes. Therefore, innovative CTT is always desirable in terms of the PEC index. The maximum exergy efficiency is Re = 10,000, ϕ= 0.02, and PR = 2. Based on the environmental analysis, the amount of carbon dioxide in the PTC equipped with an innovative CTT containing two-phase MWCNT-GO/Syltherm 800 HNF is 0.033 kg/day.

Self-catalyzed GaP nanowire MOVPE growth on Si

Typically, vapour liquid solid (VLS)-grown nanowires via metal–organic vapour phase epitaxy (MOVPE) use gold as a liquid growth catalyst. However, incorporating gold as an impurity during growth is disadvantageous. Therefore, we introduce the self-catalyzed VLS growth of GaP nanowires on Si (111) substrates via MOVPE, utilizing (deposited) Ga droplets as seed particles. To understand and optimize the growth process, the influence of various growth parameters such as Ga precursor preflow, growth temperature, growth time and V/III ratio are studied. As main findings we show that nanowire growth without strong tapering is possible. By varying the V/III gas phase ratio the tapering of nanowires can be manipulated during growth via droplet consumption. In addition, nanowires with lengths up to 10 µm and an aspect ratio of around 20 are demonstrated, showing only slight tapering. High-resolution scanning transmission electron microscopy measurements prove the zincblende crystal structure of the GaP nanowires in horizontal and vertical ultramicrotomy cuts. In vertical cross sections, a high number of microtwin boundaries perpendicular to the growth direction are found.