Azimuthal Orientation Research Articles

The impact of magnetic fields on cosmological galaxy mergers – II. Modified angular momentum transport and feedback

ABSTRACT The role of magnetic fields in galaxy evolution is still an unsolved question in astrophysics. We have previously shown that magnetic fields play a crucial role in major mergers between disc galaxies; in hydrodynamic simulations of such mergers, the Auriga model produces compact remnants with a distinctive bar and ring morphology. In contrast, in magnetohydrodynamic (MHD) simulations, remnants form radially extended discs with prominent spiral arm structure. In this paper, we analyse a series of cosmological ‘zoom-in’ simulations of major mergers and identify exactly how magnetic fields are able to alter the outcome of the merger. We find that magnetic fields modify the transport of angular momentum, systematically hastening the merger progress. The impact of this altered transport depends on the orientation of the field, with a predominantly non-azimuthal (azimuthal) orientation increasing the central baryonic concentration (providing support against collapse). Both effects act to suppress an otherwise existent bar-instability, which in turn leads to a fundamentally different morphology and manifestation of feedback. We note, in particular, that stellar feedback is substantially less influential in MHD simulations, which allows for the later accretion of higher angular momentum gas and the subsequent rapid radial growth of the remnant disc. A corollary of the increased baryonic concentration in MHD simulations is that black holes are able to grow twice as large, although this turns out to have little impact on the remnant’s development. Our results show that galaxy evolution cannot be modelled correctly without including magnetic fields.

Creation of galaxy-shaped vortex relief structures in azo-polymers with petal-like beams.

We demonstrate the formation of surface relief structures in azo-polymers which exhibit multiple spiral arms, through irradiation of a rotating petal-like beam formed by the coherent superposition of Laguerre-Gaussian modes with opposite handedness. Intriguingly, the fabricated relief structures reflect full geometric parameters of the irradiated petal beam, such as handedness, topological charge, initial azimuthal phase and even ellipticity, corresponding to azimuthal and polar angles along equator and meridian planes of an orbital Poincaré sphere. The handedness, or direction of rotation, of the fabricated structures with multiple spiral arms could be controlled via the rotation and polarization directions of the irradiating laser field. This effect highlights an exotic coupling between the optical intensity gradient induced mass transport of the irradiated material and the spin angular momentum characteristics of the irradiating optical field. The azimuthal orientation of the surface relief structures could also be tuned by altering the initial relative phase between the coherently superposed Laguerre-Gaussian modes with opposite handedness, constituting the irradiating petal laser field. This work offers new insights into fundamental interactions which occur between light and matter, and we believe, will pave the way towards advanced technologies, such as ultrahigh density optical data storage.

Metalloporphyrins on oxygen-passivated iron: Conformation and order beyond the first layer

On-surface metal porphyrins can undergo electronic and conformational changes that play a crucial role in determining the chemical reactivity of the molecular layer. Therefore, accessing those properties is pivotal for their implementation in organic-based devices. Here, by means of photoemission orbital tomography supported by density functional theory calculations, we investigate the electronic and geometrical structure of two metallated tetraphenyl porphyrins (MTPPs), namely ZnTPP and NiTPP, adsorbed on the oxygen-passivated Fe(100)-p(1 × 1)O surface. Both molecules weakly interact with the surface as no charge transfer is observed. In the case of ZnTPP, our data correspond to those of moderately distorted molecules whereas NiTPP exhibits a severe saddle-shape deformation. From additional experiments on NiTPP multilayer films, we conclude that this distortion is a consequence of the interaction with the substrate, as the NiTPP macrocycle of the second layer turns out to be flat. We further find that distortions in the MTPP macrocycle are accompanied by an increasing energy gap between the highest occupied molecular orbitals (HOMO and HOMO-1). Our results demonstrate that photoemission orbital tomography can simultaneously probe the energy level alignment, the azimuthal orientation, and the adsorption geometry of complex aromatic molecules even in the multilayer regime.

Potential and anion effects on the adsorption of 3′,4′-bis(hexylthio)-2,2′:5′,2′'-terthiophene on Au(1 1 1) electrode characterized by in situ STM

The adsorption of organic molecules on gold electrodes serves as a model to understand the organic/inorganic electrified interface, which is relevant to the study of molecular electronics and organic thin film semiconductors. Our previous study on terthiophene (TT) adsorption on an Au(111) electrode shows that immersing Au(111) crystals in a TT ethanol dosing solution installs an ordered TT adlayer on the sample. The current study addresses the adsorption of 3′,4′-bis(hexylthio)-2,2′:5′,2′'-terthiophene (DTDST), a molecule with a TT backbone attached with two thiolhexyl chains, on an ordered Au(111) electrode. High-quality STM images were obtained to reveal the internal and 2D spatial structures of DTDST admolecules. The potential greatly influenced the organization of DTDST on the ordered Au(111) electrode. Although the pristine DTDST adlayer was disordered, it transformed into ordered Au(111) - (3√3 × 9) and (5√3 × 26) structures after applying a potential more negative than 0 V (vs. Ag/AgCl) in 0.1 M H2SO4 and HClO4, respectively. Shifting the potential more positive than 0.25 V resulted in coadsorption of bisulfate anions and restructuring of the DTDST adlayer. High-quality molecular resolution STM images were collected to reveal the azimuthal orientation of the DTDST admolecule on the Au(111) electrode. The thiolhexyl chains of DTDST admolecules could arrange in such a way that allowed intermolecular van der Waals interactions. Oxidation of adsorbed DTDST molecules to yield oligomers was also revealed by in situ STM.

Controlled wiring of disclination lines between patterned photoalignment layers in nematic liquid crystal

On demand creation of topological defect configurations is a relevant topic for theoretical studies but also enables new developments in the field of photonics, stimuli-responsive actuators and colloidal assemblies. Liquid crystals (LCs) provide a versatile and technologically relevant material system to study topological defects, and photoalignment enables complex surface patterning that includes the formation of defects. This work is based on periodic defect grids of +1/2 and −1/2 defects, imposed at the top and bottom surface of a LC cell. The periods at the two substrates are slightly different and the azimuthal orientation of the defects is varied, so that different types of disclination interconnections are formed in the bulk of the LC. Some disclination lines connect defects at opposing substrates, while others connect defects on the same substrate. The experimentally generated configurations are simulated with the help of finite element Q-tensor simulations in order to get a detailed understanding of the defect formation. The optical appearance in polymerizing optical microscopy images is compared to optical simulations to verify the validity of the director configurations.

Filamentary-like structures of plasma in a small 3-kJ dense plasma-focus discharge in pure deuterium

Filament-like structures were observed during discharges in a small 3-kJ plasma focus device operated with pure deuterium. These structures were recorded by means of two different laser diagnostic techniques: a schlieren system and a differential laser interferometry. They present the novel fine-scale (submillimeter) plasma structures recorded during the radial implosion, at the pinch stagnation, at the development of instabilities, and during a decay of the dense plasma column, when hard x-rays and fusion-produced neutrons were generated. The temporal uncertainty of these observations was about 2 ns, and the spatial one amounted to 40 μm. The filamentation seems be a natural and spontaneous process which occurs in high-current, hot, and dense plasmas produced in plasma focus devices. The observed filaments have usually longitudinal and/or azimuthal orientations. Their higher plasma density and appearance in regions of the measured and assumed current flows can be interpreted as the formation of plasma-current filaments with concentrated magnetic energy. These filamentary effects should be studied due to their possible role during the evolution of instabilities and the formation of small sources emitting fast electrons and ions.

VALIDATION OF PHOTOVOLTAIC MODEL FOR APPLICATION IN A DISTRIBUTED ENERGY SOURCE USING WEATHER DATA

This work presents a photovoltaic model for a simulation of the electric energy production of a distributed energy system. The model will be validated through measured weather data and energy produced by an 88.04 kWp power plant installed on the Federal University of Espírito Santo (UFES) in Vitória. The validation consists of comparing the real power data acquired by the photovoltaic plant and the power data calculated from the model using weather data, specifications of the panels and inverters and the constructive characteristics of the system. The proposed model is based on the paper “Management of an island and grid-connected microgrid using hybrid economic model predictive control with weather data”, Applied Energy, v. 278, 2020, https://doi.org/10.1016/j.apenergy.2020.115581. In addition, the model has been improved with the inclusion of new intrinsic parameters of the material, the calculation of losses and the adjustments for different tilt angles and azimuth orientations. Results of this method reveal that the model was able to reproduce the behavior of the real photovoltaic plant, presenting a mean absolute percentage error of 8.8% between real and simulated data.

Türkiye’nin İstanbul Şehrindeki PV Panellerinin Optimum Eğim ve Yüzey Oryantasyon Açılarının Hesaplanması

Because of the shadow of high buildings and huge urban development that the world is witnessing, especially in the large cities such as Istanbul, this led to prevent taking advantage from a large part of the falling solar radiation, which led to finding alternative solutions for the purpose of benefiting from the falling solar radiation. Among these solutions is the adjusting solar panel at the optimum slope and orientation angle. So the purpose of this study is to determine the optimum slope and orientation angle for a photovoltaic panel in Istanbul (Turkey) with coordinate of (41° 1′ 0″ N, 28° 58′ 0″ E), latitude of (Ø = 41.0167), and explain the effect of azimuth angle on the optimum slope angle of solar radiation on the photovoltaic panel. A mathematical model was developed by Klein and Theilacker to determine any surface azimuth angle (ϒ) was used to estimate the total solar radiation on the slope photovoltaic panel surface, also Liu – Jordan model was used for calculating the optimum tilt angle for south face direction and then comparison results with two models. In our study we used a Microsoft Excel spreadsheet to determine optimum slope (β) and azimuth (orientation) (ϒ) surface angles for any city only by changing the coordinate and horizontal solar radiation of the selected city. For calculation purposes, horizontal solar radiation data for the city of Istanbul was obtained from the prediction of worldwide energy resources (power) by NASA. The optimum tilt (β) and azimuth (ϒ) angles were determined by searching for the values of angles for which the total radiation on the PV surface was maximum throughout the year. And for the specific azimuth angle (ϒ) changes from (0 to 90) degree It is found that the optimum tilt angle (β) should be changed to observe the maximum solar radiation. The annual maximum solar radiation in Istanbul city for azimuth angle greater than 0o was 6033 Mj/m2 at azimuth angle equal to 10o and tilt angle equal to 30o.

The accuracy of approximating P-wave traveltimes in orthotropic media using VTI equations

SUMMARY Analysis of azimuthally varying non-hyperbolic moveout of P-wave traveltimes in orthotropic media can provide valuable information for reservoir fracture characterization and seismic data processing. Moveout velocities and azimuthal orientation of the two vertical symmetry planes plus anellipticity parameters defined for the three symmetry planes of an orthotropic medium can be estimated from the inversion of P-wave traveltimes measured in long-spread, wide-azimuth seismic surveys. Several orthotropic moveout equations have been developed to this date that can be used in the traveltime data inversion. The accuracy of the inversion results is primarily determined by the complexity of the equation and the assumptions (i.e. elastic or acoustic) made to derive it. Here, we show that often simpler moveout equations derived for transverse isotropy media with vertical axis of symmetry (VTI) can be used to estimate anellipticity parameters of the orthotropic media with high accuracy. We make an accuracy comparison analysis between non-hyperbolic moveout equations that are widely used in modelling P-wave traveltimes in VTI media. Our comparison analysis is based on the accuracy of estimating anellipticity parameters defined for two vertical [η(1) and η(2)] and one horizontal [η(3)] symmetry planes of a wide range of orthotropic media. The anellipticity parameters are estimated from the inversion of numerical traveltimes that are generated for a single and horizontal orthotropic layer. We show that for the survey geometry used in this analysis, most of the moveout equations can produce reliable estimates of the anellipticity parameters η(1) and η(2). Despite the availability of traveltime data from wide-azimuths and long source–receiver offsets, none of the moveout equations can estimate η(3) as accurate as η(1) and η(2) estimations. We show that while all the equations produce mostly accurate estimates of η(1) and η(2), generalized moveout approximation (GMA) provides the greatest accuracy. We also assess the validity of using GMA to invert P-wave traveltimes for three anellipticity parameters in terms of anisotropy in the background medium, fracture weakness, source–receiver offset (group angle) and traveltime data coverage in both the vertical (dip) and horizontal (azimuthal) planes. We show that, for a reasonable offset range, GMA can be reliably used to estimate anellipticity parameters η(1) and η(2) for an orthotropic medium that is constructed by intensive fracturing of a host medium with strong VTI anisotropy.

Detection and Direction Finding of Transport Objects in Seismoacoustic Observation Systems

The problem of passive geophysical monitoring of transport objects using acoustic and three-component seismic oscillations is considered. The solution is based on the application of spectral-time analysis, the method of spectral-polarization processing, the selection of informative frequencies of oscillations and the determining the direction finding on the object. The azimuthal orientation of the major axis position of the scattering ellipse obtained by polarization processing makes it possible to determine the direction finding. Numerical estimates of the accuracy of problem solving in a field experiment have been obtained. The proposed approach is based on consideration of the spatial-frequency characteristics of the object and its seasonal variation.

Metamaterial properties of Babinet complementary complex structures

Single and multiple layers of sub-wavelength periodic Babinet complementary patterns composed of rounded nano-object miniarrays were investigated. In case of illumination with linearly and circularly polarized light the azimuthal orientation and handedness (in)dependence of (cross-polarized) copolarized transmitted signal components was proven for all types of patterns. Considerable (weak) asymmetric transmission was demonstrated in extended bands exclusively for both types of copolarized (cross-polarized) signals transmitted through single layer of convex miniarrays. Three-dimensional structures constructed with convex–concave–convex complex pattern-layers resulted in a negative index at the visible region boundary both for linearly and circularly polarized light illuminations. This is because dipolar modes on the convex nano-objects are synchronized with co-existent reversal dipoles on the concave nano-objects via interlayer coupling. Although during linearly polarized light illumination, the interlayer interaction decouples the localized and propagating modes excitable on the concave pattern in the 90° azimuthal orientation, the synchronization via tilted-rotating nanoring dipoles is almost perfect in the 0° azimuthal orientation. For circularly polarized light illumination, both the dispersion maps and the negative index phenomena synthesize the characteristics of the two orthogonal linearly polarized light illuminations. Important aspect is the appearance of a small/intermediate (large) time-averaged amplitude magnetic dipole due to the tilted (twisted) electric dipole on the concave nanoring, which less/more quickly turns (continuously rotates) with large/intermediate (small) out-of-plane tilting, when illumination is realized with linearly polarized light in the 90°/0° azimuthal orientation (with circularly polarized light). The location of the negative index can be predicted based on the copolarized transmittance signals computed for circularly polarized light illumination by using the linear base representation of Jones transmission matrix elements.

Effect of Residual Carbon on Spin‐Polarized Coupling at a Graphene/Ferromagnet Interface

AbstractVertical stacks of graphene and ferromagnetic layers are predicted to be efficient spin filters, while the experimentally observed figures of merit systematically remain below the theoretical predictions. According to general consensus, a vaguely defined interface contamination is found responsible for this discrepancy. Here, it is demonstrated how the spin‐polarized electronic structure of single‐layer graphene supported on a ferromagnetic cobalt substrate is affected by the presence of an interfacial carbidic buffer layer, formed by residual carbon present in the Co substrate. It is found that the Co‐C hybridized single‐spin state near the Fermi level disappears upon thermal segregation of bulk carbon at the graphene–Co interface, which determines the electronic decoupling of graphene from the ferromagnetic support and consequently, the suppression of net spin polarization. These observations are shown to be independent of the graphene azimuthal orientation with respect to the high symmetry directions of the substrate. The findings provide clear evidence that the realization of highly polarized spin currents in graphene/ferromagnet heterostacks depends on careful control of the graphene growth process in order to eliminate interfacial carbon.

Titin activates myosin filaments in skeletal muscle by switching from an extensible spring to a mechanical rectifier

Titin is a molecular spring in parallel with myosin motors in each muscle half-sarcomere, responsible for passive force development at sarcomere length (SL) above the physiological range (>2.7 μm). The role of titin at physiological SL is unclear and is investigated here in single intact muscle cells of the frog (Rana esculenta), by combining half-sarcomere mechanics and synchrotron X-ray diffraction in the presence of 20 μM para-nitro-blebbistatin, which abolishes the activity of myosin motors and maintains them in the resting state even during activation of the cell by electrical stimulation. We show that, during cell activation at physiological SL, titin in the I-band switches from an SL-dependent extensible spring (OFF-state) to an SL-independent rectifier (ON-state) that allows free shortening while resisting stretch with an effective stiffness of ~3 pN nm-1 per half-thick filament. In this way, I-band titin efficiently transmits any load increase to the myosin filament in the A-band. Small-angle X-ray diffraction signals reveal that, with I-band titin ON, the periodic interactions of A-band titin with myosin motors alter their resting disposition in a load-dependent manner, biasing the azimuthal orientation of the motors toward actin. This work sets the stage for future investigations on scaffold and mechanosensing-based signaling functions of titin in health and disease.

Pressure and Thermal Characterisation of Dynamic Instabilities During Flow Boiling in Micro/Mini-channels at Different Azimuth Orientations

• Flow boiling in microchannels at different azimuthal orientation are investigated. • 3 instability types were identified: two-phase mixing, minor and major reverse flow. • Flow instability improves the average heat transfer coefficient by up to 52% • Top-heated channels had the greatest increase in heat transfer coefficient. • Instability frequency increased with mass flux increases and heat flux decreases. Fluid instability was investigated experimentally during flow-boiling of Perfluorohexane (FC-72) in a flat horizontal micro/mini channel with a hydraulic diameter of 909 μ m and an aspect ratio of 10 (5 mm x 0.5 mm). One-sided heating at different azimuth channel orientations ( θ ) in terms of gravity were considered, which ranged from bottom-heating ( θ = 0°) to top-heated ( θ = 180°) in 30° increments. Mass fluxes of 10, 20 and 40 kg/m 2 s were considered at a saturation temperature of 56 °C. Flow instability and the resulting thermal and pressure responses were identified and studied via high-speed video, infrared thermography, and pressure measurements. Various mass flux and heat flux combinations at each channel orientation leading to flow instabilities categorised into two-phase mixing, minor reverse flow and major reverse flow, were studied. Increased mass flux resulted in more frequent and more severe flow instability, irrespective of the channel orientation. Increased heat flux resulted in an increased number of operating conditions that were susceptible to flow instability, but the instabilities occurred at lower frequencies. In general, orientations that had a horizontal heated surface ( θ = 0° and 180°) were most susceptible to flow instability, while the intermediate azimuthal rotations ( θ = 30°, 60° and 90°) exhibited flow instability only at the highest mass flux. It was also found that flow instability often resulted in improved heat transfer performance, particularly in regions of the channel that were occupied by liquid. Where-as no direct relationship between the mass flux and the heat transfer performance improvement could be identified, it was found that better heat transfer improvements were obtained at higher heat fluxes. At the highest mass flux, cases that were horizontal and heated from above ( θ = 180°) exhibited heat transfer coefficient improvements (during instability) of up to 77% and 275% in the single-phase and two-phase regions respectively compared to baseline stable conditions.

Investigating high permeable zones in non-volcanic geothermal systems using lineament analysis and fault fracture density (FFD): northern Konawe Regency, Indonesia

Indonesia has high geothermal potential comprising 40% of the world’s potential geothermal energy, volcanic and non-volcanic systems. Volcanic systems have witnessed more exploration activities for geothermal resources compared to non-volcanic systems. A high potential non-volcanic system in Indonesia is located in the northern part of Konawe, Southeast Sulawesi. Previous research had identified surface temperature anomaly (high temperature) and some surface manifestations for this area, specifically in the northeast part of Wawolesea. However, the source of surface manifestations and permeable zones as an implication of a good reservoir are still unknown. Therefore, this research aims to investigate the permeable zones and geothermal potential in the non-volcanic geothermal system of north Wawolesea by applying lineaments analysis and the fault fracture density (FFD) method. A total of 1694 major and minor lineaments were manually delineated using ArcGIS based on Digital Elevation Model Nasional (DEMNAS). FFD map and rose diagrams displayed the orientation of all lineaments and structures with the major lineaments trending NNE–SSW, whereas the minor lineaments showed irregular distribution and orientation. Field measurements also show the same azimuth orientation for the mapped fractures. Five zones were characterized by high FFD values (2.81–4.54 km/km2). One of the extensively fractured zones (Zone C) is located between Meluhu and Lembo, covering an area of around 19.39 km2. This area is interpreted to be highly permeable and suggestive of a recharge area that contributes to surface manifestation in the Wawolesea. Therefore, the area between Meluhu and Lembo in the northern part of Konawe shows high geothermal potential due to its planar morphology and high FFD values. This study allows an improved understanding of how fracture geometry, distribution and density control the permeability in geothermal reservoirs.

Sublayer-Enhanced Growth of Highly Ordered Mn5Ge3 Thin Film on Si(111)

Mn5Ge3 epitaxial thin films previously grown mainly on Ge substrate have been synthesized on Si(111) using the co-deposition of Mn and Ge at a temperature of 390 °C. RMS roughness decreases by almost a factor of two in the transition from a completely polycrystalline to a highly ordered growth mode. This mode has been stabilized by changing the ratio of the Mn and Ge evaporation rate from the stoichiometric in the buffer layer. Highly ordered Mn5Ge3 film has two azimuthal crystallite orientations, namely Mn5Ge3 (001) [1-10] and Mn5Ge3 (001) [010] matching Si(111)[-110]. Lattice parameters derived a (7.112(1) Å) and c (5.027(1) Å) are close to the bulk values. Considering all structural data, we proposed a double buffer layer model suggesting that all layers have identical crystal structure with P6₃/mcm symmetry similar to Mn5Ge3, but orientation and level of Si concentration are different, which eliminates 8% lattice mismatch between Si and Mn5Ge3 film. Mn5Ge3 film on Si(111) demonstrates no difference in magnetic properties compared to other reported films. TC is about 300 K, which implies no significant excess of Mn or Si doping. It means that the buffer layer not only serves as a platform for the growth of the relaxed Mn5Ge3 film, but is also a good diffusion barrier.

SEARCH FOR SMALL-SIZED OBJECTS ON THE UNDERLYING SURFACE IN FRONT OF THE AIRCRAFT

The method of searching of small-sized ground or surface objects with unknown coordinates is proposed. The search is carried out using the thermal imaging or other IR remote sensing system (RS) of underlying surface (US) in front of the aircraft. The small size of objects requires the use of narrow fields of view for detection and recognition at ranges that allow to carry out operational actions, which are provided for by the flight mission for rescue operations on land and at sea or for aircraft emergency landing on an unprepared site. Two tasks are solved: 1) the maximization of the guaranteed bandwidth of objects searching on US with given characteristics of RS and aircraft speed; 2) the determination of the optimal characteristics of remote sensing systems and aircraft speed for a given search bandwidth of the US.A periodic change in the azimuthal orientation of the narrow field of view (automatic scanning of the US by the field of view of the IR system) is used for solving given tasks. For a given operating range of the IR system the proposed algorithm ensures that the pilot or operator can view the runway on US without “dead” zones (unseen areas). The optimal value of the search effort corresponding to the detection and recognition of objects is determined. The proposed algorithm implements symmetrical scanning (scanned areas of the same shape are formed to the left and right of the flight path on US). The symmetric scanning equation is derived for prediction search efficiency. The solution of given equation makes it possible to find the dependence of the guaranteed search bandwidth on the operating range of ranges in which detection and recognition are possible for given weather conditions. The examples of using the derived equation when searching for objects in simple and difficult weather conditions are given.

Fracture Characterization Combining Borehole Acoustic Reflection Imaging and Geomechanical Analyses

The assessment of fracture fluid-conducting capability in reservoirs is of great significance for hydrocarbon production, especially for tight reservoirs with fractures as the main reservoir fluid transport conduits. In recent years, dipole shear-wave reflection imaging technology has been effectively applied to identify near-well formation fractures and determine their orientation, but the evaluation of the fluid-conducting effectiveness of the acoustically imaged fractures remains a challenging task. To accomplish this task, this paper proposes a method that combines dipole acoustic reflection imaging with a geomechanical analysis to determine the stress state on the fracture surface. The fracture orientation and inclination, as obtained from the borehole reflection imaging, are combined with in-situ stress conditions to calculate the effective stress state of the fracture surface using a three-dimensional (3D) Mohr-diagram analysis, which, when compared with the Mohr-Coulomb failure criterion, determines whether the fracture is in the critically stressed state and is therefore fluid conductive. Most importantly, our analysis shows that the typical 180° fracture orientation azimuth uncertainty in the cross-dipole shear-wave imaging does not affect the determination of the stress state on the fracture surface in the Mohr-diagram analysis so that the two methods can be effectively combined to form a new method for evaluating the fluid-conducting effectiveness of fractures. The application examples from fractured reservoirs show the effectiveness of the new evaluation method, and the evaluation results can be used to provide useful information for field development and production planning.

Defining domain-specific orientational order in the desmosomal cadherins

Desmosomes are large, macromolecular protein assemblies that mechanically couple the intermediate filament cytoskeleton to sites of cadherin-mediated cell adhesion, thereby providing structural integrity to tissues that routinely experience large forces. Proper desmosomal adhesion is necessary for the normal development and maintenance of vertebrate tissues, such as epithelia and cardiac muscle, while dysfunction can lead to severe disease of the heart and skin. Therefore, it is important to understand the relationship between desmosomal adhesion and the architecture of the molecules that form the adhesive interface, the desmosomal cadherins (DCs). However, desmosomes are embedded in two plasma membranes and are linked to the cytoskeletal networks of two cells, imposing extreme difficulty on traditional structural studies of DC architecture, which have yielded conflicting results. Consequently, the relationship between DC architecture and adhesive function remains unclear. To overcome these challenges, we utilized excitation-resolved fluorescence polarization microscopy to quantify the orientational order of the extracellular and intracellular domains of three DC isoforms: desmoglein 2, desmocollin 2, and desmoglein 3. We found that DC ectodomains were significantly more ordered than their cytoplasmic counterparts, indicating a drastic difference in DC architecture between opposing sides of the plasma membrane. This difference was conserved among all DCs tested, suggesting that it may be an important feature of desmosomal architecture. Moreover, our findings suggest that the organization of DC ectodomains is predominantly the result of extracellular adhesive interactions. We employed azimuthal orientation mapping to show that DC ectodomains are arranged with rotational symmetry about the membrane normal. Finally, we performed a series of mathematical simulations to test the feasibility of a recently proposed antiparallel arrangement of DC ectodomains, finding that it is supported by our experimental data. Importantly, the strategies employed here have the potential to elucidate molecular mechanisms for diseases that result from defective desmosome architecture.

Glare-Free Airport-Based Photovoltaic System via Optimization of Its Azimuth Angle

Photovoltaic modules and systems (PVs) play an important role in achieving self-sustainable airports. In particular, airport-based PVs (A-PVs) have access to their full potential because airports are typically located in open spaces. However, the reflection of solar light by A-PVs’ front glass is unavoidable and may cause an accident due to solar glare (SG). In this study, we theoretically calculated the risk of SG from A-PVs depending on their azimuthal installation orientation (θPV) and derived a general design rule for minimizing the SG. The simulation reveals that the SG from A-PVs facing the runway and potential flight path causes after-images in pilots and ground workers throughout the year (>800 h/year). On the other hand, modifying their θPV, facing opposite runways and flight paths, significantly reduces the SG (<1 h/year) by reflecting the incident light outside the aircraft route. Although the θPV is not southward, their annual energy generation with an optimized θPV decreases by only 5–7% compared with A-PVs facing southward. This universal design approach is verified at four other airports, confirming the model’s validity. We believe our study will contribute to more solar light harvesting at airports without glare hazards.