Tilt Angle Research Articles

Clinical Impact of Thermotherapy and Spinal Twisting Massage on Chronic Non-Specific Spinal Pain.

As the prevalence of chronic non-specific spinal pain rises, the utilization of diverse massage devices for therapeutic intervention increases rapidly. However, research on their mechanisms, particularly those involving spinal twisting, is limited. This study was designed to evaluate the impact of heat application and spinal twisting massage techniques on individuals suffering from chronic non-specific spinal pain. A total of 36 individuals were divided into two groups: a control group (18 participants) and an experimental group (18 participants). The experimental group received heat treatment plus spinal twisting massage twice a week for four weeks, while the control group received heat therapy plus traditional vibration massage techniques. Effectiveness was measured using the Visual Analog Scale (VAS), the Pressure Pain Threshold (PPT), the Korean Western Ontario and McMaster Universities (K-WOMAC) Index, spine tilt, and Cobb angle. VAS, K-WOMAC, and PPT significantly improved in both groups at all three time points. VAS notably decreased in the experimental group compared to the control group (p-value: 0.0369). Despite improvements in K-WOMAC and PPT scores within the experimental group, statistical significance remained elusive. Furthermore, spine tilt and Cobb angle showed no significant differences from baseline to the 6th week. In conclusion, the application of thermotherapy coupled with twisting massage demonstrates significant efficacy in mitigating chronic non-specific spinal pain, surpassing the pain-relief outcomes achieved through heat therapy in combination with standard vibration massage techniques.

Tuning critical current density properties of YBa2Cu3O y thin films under longitudinal magnetic field by using heavy-ion irradiation

We attempted to improve the critical current density J c under a longitudinal magnetic field (LMF) by using columnar defects (CDs) tilted toward the transport current, where the CDs were produced with 80 MeV Xe ions at an incident angle(s) up to φ i = 87.5° relative to the c-axis of YBa2Cu3O y thin films. The formation of CDs extending throughout the film was confirmed by cross-sectional transmission electron microscopy. The CDs tilted at φ i = 87.5° weakened the magnetic field dependence of J c under the LMF, providing a J c higher than that of the unirradiated film in a high magnetic field. This is the first study to demonstrate that CDs and/or irradiation defects contribute to flux pinning under the LMF in high-T c superconductors. In addition, the J c under LMF was sensitive to the tilt angle of the CDs: the J c was reduced by CDs tilted not only at φ i = 0°, but also at a slightly larger angle relative to the ab-plane, i.e. φ i = 85°. The introduction of CDs rather disturbs the LMF effect because of the large volume passing through the film thickness, unless the tilt angles of the CDs are within the narrow angular region effective for the LMF effect.

Thermodynamic model for electro-optical properties of antiferroelectric phase in mesogen W-330-3 and W-331-3

ABSTRACT A thermodynamic model developed by our group has been employed to explore the electro-optical properties of the chiral antiferroelectric smectic C (Sm C A ∗ ) phase. In the present study, the temperature dependence of tilt angle and spontaneous polarization of binary ferroelectric mixtures represented as W-330-3 and W-331-3 exhibiting ferroelectric Sm C* and antiferroelectric Sm C A ∗ phase has been investigated. Within the framework of this model, the free-energy density characterizing the system featuring the Sm C A ∗ phase is expressed as a series expansion that incorporates all pertinent degrees of freedom: tensor orientational order Q ij , scalar smectic order ψ, polarization vector P, wave vector q of the helix and the resulting coupling terms between these order parameters. The values of Landau coefficients featured in the expansion series are derived from experimental data (tilt angle and spontaneous polarization) of W-330-3 and W-331-3. A substantial agreement between the theoretical predictions and experimental observations has been found.

Atomistic Characterization of Healthy and Damaged Hair Surfaces: A Molecular Dynamics Simulation Study of Fatty Acids on Protein Layer.

Amid the bourgeoning demand for in-silico designed, environmentally sustainable, and highly effective hair care formulations, a growing interest is evident in the exploration of realistic computational model for the hair surface. In this work, we present an atomistic model for the outermost layer of the hair surface derived through molecular dynamics simulations, which comprises 18-Methyleicosanoic acid (18-MEA) fatty acid chains covalently bound onto the keratin-associated protein 10-4 (KAP10-4) at a spacing distance of ~1 nm. Remarkably, this hair surface model facilitates the inclusion of free fatty acids (free 18-MEA) into the gaps between chemically bound 18-MEA chains, up to a maximum number that results in a packing density of 0.22 nm2 per fatty acid molecule, consistent with the optimal spacing identified through free energy analysis. Atomistic insights are provided for the organization of fatty acid chains, structural features, and interaction energies on protein-inclusive hair surface models with varying amounts of free 18-MEA (FMEA) depletion, as well as varying degrees of anionic cysteic acid from damaged bound 18-MEA (BMEA), under both dry and wet conditions. In the presence of FMEA and water, the fatty acid chains in a pristine hair surface prefers to adopt a thermodynamically favored extended chain conformation, forming a thicker protective layer (~3 nm) on the protein surface. Our simulation results reveal that, while the depletion of FMEA can induce a pronounced impact on the thickness, tilt angle, and order parameters of fatty acid chains, the removal of BMEA has a marked effect on water penetration. There is a "sweet spot" spacing between the 18-MEA whereby damaged hair surface properties can be reinstated by replenishing FMEA. Through the incorporation of the protein layer and free fatty acids, the hair surface models presented in this study enables a realistic representation of the intricate details within the hair epicuticle, facilitating a molecular scale assessment of surface properties during the formulation design process.

Quantifying Chemical Reactions and Interfacial Properties at Buried Polymer/Polymer Interfaces.

Maleic anhydride (MAH)-modified polymers are used as tie layers for binding dissimilar polymers in multilayer polymer films. The MAH chemistry which promotes adhesion is well characterized in the bulk; however, only recently has the interfacial chemistry been studied. Sum frequency generation vibrational spectroscopy (SFG) is an interfacial spectroscopy technique which provides detailed information on interfacial chemical reactions, species, and molecular orientations and has been essential for characterizing the MAH chemistry in both nylon and ethyl vinyl alcohol copolymer (EVOH) model systems and coextruded multilayer films. Here, we further characterize the interfacial chemistry between MAH-modified polyethylene tie layers and both EVOH and nylon by investigating the model systems over a range of MAH concentrations. We can detect the interfacial chemical reaction products between MAH and the barrier layer at MAH concentrations of ≥0.022 wt % for nylon and ≥0.077 wt % for EVOH. Additionally, from the concentration-dependent reaction reactant/product SFG peak positions and the product imide or ester/acid C═O group tilt angles extracted from the polarization-dependent SFG spectra, we quantitatively observe concentration-dependent changes to both the interfacial chemistry and interfacial structure. The interfacial chemistry and molecular orientation as a function of MAH concentration are well correlated with the adhesion strength, providing important quantitative information for the future design of MAH-modified tie layers for a variety of important applications.

Effects of chain-chain interaction on the configuration of short-chain alkanethiol self-assembled monolayers on a metal surface.

Surface-specific sum frequency generation vibrational spectroscopy is applied to study the molecular configuration of short-chain n-alkanethiol self-assembled monolayers (SAMs with n = 2-6) on the Au surface. For monolayers with n≥ 3, the alkanethiols are upright-oriented, with the CH3 tilt angle varying between ∼33° and ∼46° in clear even-odd dependency. The ethanethiol monolayer (n = 2) is, however, found to exhibit a distinct lying-down configuration with a larger methyl tilt angle (67°-79°) and a smaller CH2 tilt angle (56°-68°). Such a unique configurational transition from n = 2 to n≥ 3 discloses the steric effect owing to chain-chain interaction among neighboring molecules. Through density functional theory calculations, the transition is further confirmed to be energetically favorable for thiols on a defective reconstructed Au(111) surface but not on the pristine one. Our study highlights the roles of the chain-chain interaction and the substrate surface atomic structure when organizing SAMs, offering a strategic pathway for exploiting their applications.

The Role of Pelvic Compensation in Sagittal Balance and Imbalance: The Impact of Pelvic Compensation on Spinal Alignment and Clinical Outcomes Following Adult Spinal Deformity Surgery.

The Scoliosis Research Society (SRS)-Schwab system does not include a pelvic compensation (PC) subtype, potentially contributing to gaps in clinical characteristics and treatment strategy for deformity correction. It also remains uncertain as to whether PC has differing roles in sagittal balance (SB) or imbalance (SI) status. To compare radiological parameters and SRS-22r domains between patients with failed pelvic compensation (FPC) and successful pelvic compensation (SPC) based on preoperative SB and SI. A total of 145 adult spinal deformity patients who received deformity correction were analyzed. Radiographic and clinical outcomes were collected for statistical analysis. Patients were classified into 4 groups based on the median value of PT/PI ratio (PTr) and the cutoff value of SB. Patients with low PTr and high PTr were defined as FPC and SPC, respectively. Radiographic and clinical characteristics of different groups were compared. Patients with SPC exhibited significantly greater improvements in lumbar lordosis, pelvic tilt, PTr, and T1 pelvic angle as compared to patients with FPC, irrespective of SB or SI. No apparent differences in any of SRS-22r domains were observed at follow-up when comparing the SB-FPC and SB-SPC patients. However, patients with SI-SPC exhibited significantly better function, self-image, satisfaction, and subtotal domains at follow-up relative to those with SI-FPC. When SI-FPC and SI-SPC patients were subdivided further based on the degree of PI-LL by adjusting for age, the postoperative function and self-image domains were significantly better in the group with overcorrection of PI-LL than undercorrection of PI-LL in SI-FPC patients. However, no differences in these SRS-22r scores were observed when comparing the subgroups in SI-SPC patients. Flexible pelvic rotation is associated with benefits to the correction of sagittal parameters, irrespective of preoperative SB or SI status. However, PC is only significantly associated with clinical outcomes under SI. Patients with SI-FPC exhibit poorer postoperative clinical outcomes, which should be recommended to minimize PI-LL.

Influence of tool velocity ratio on force-torque and mechanical properties of friction stir welded 2050-T84 Al-Li alloy plates

Aluminium-lithium (Al-Li) alloy is the most prominent alloy used in the aerospace industry’s internal structure and wings due to its improved physical and mechanical properties. The present study introduces a novel investigation into the joining of Al–Li alloy 2050-T84 using friction stir welding (FSW) at different tool velocity ratios (TVR) of 0.6, 0.8, and 1, respectively (i.e., the amalgamation of various process parameters like tool rotational speed (TRS of 600, 1000, and 1400 rpm and traverse speed of 60, 120, and 240 mm min−1) and constant tool tilt angle (1.5°). A threaded taper tool was used for joining the Al–Li alloy 2050-T84. This work aims to ascertain the effects of varying tool velocity ratios (TVR; rotational speed/traverse speed) on macrostructure, grain size distribution in the nugget zone, and mechanical strength of the welded specimens. The experimental results reveal that increasing the tool velocity ratio increases the grain size and decreases the welded specimen’s ultimate strength and hardness values. Higher tensile strength (403.2 MPa), micro-hardness values (122.15 HV0.1), and joint efficiency (75.49) of welded specimens are achieved at low TVR (0.6), and ductile failure is observed in all welded samples. Additionally, it is noticed that the stirred zone size increased with increasing the velocity ratio.

Does high-latitude ionospheric electrodynamics exhibit hemispheric mirror symmetry?

Abstract. Ionospheric electrodynamics is a problem of mechanical stress balance mediated by electromagnetic forces. Joule heating (the total rate of frictional heating of thermospheric gases and ionospheric plasma) and ionospheric Hall and Pedersen conductances comprise three of the most basic descriptors of this problem. More than half a century after identification of their central role in ionospheric electrodynamics, several important questions about these quantities, including the degree to which they exhibit hemispheric symmetry under reversal of the sign of dipole tilt and the sign of the y component of the interplanetary magnetic field (so-called “mirror symmetry”), remain unanswered. While global estimates of these key parameters can be obtained by combining existing empirical models, one often encounters some frustrating sources of uncertainty: the measurements from which such models are derived, usually magnetic field and electric field or ion drift measurements, are typically measured separately and do not necessarily align. The models to be combined moreover often use different input parameters, different assumptions about hemispheric symmetry, and/or different coordinate systems. We eliminate these sources of uncertainty in model predictions of electromagnetic work J⋅E (in general not equal to Joule heating ηJ2) and ionospheric conductances by combining two new empirical models of the high-latitude ionospheric electric potential and ionospheric currents that are derived in a mutually consistent fashion: these models do not assume any form of symmetry between the two hemispheres; are based on Apex magnetic coordinates (denoted Apex), spherical harmonics, and the same model input parameters; and are derived exclusively from convection and magnetic field measurements made by the Swarm and CHAMP satellites. The model source code is open source and publicly available. Comparison of high-latitude distributions of electromagnetic work in each hemisphere as functions of dipole tilt and interplanetary magnetic field clock angle indicates that the typical assumption of mirror symmetry is largely justified. Model predictions of ionospheric Hall and Pedersen conductances exhibit a degree of symmetry, but clearly asymmetric responses to dipole tilt and solar wind driving conditions are also identified. The distinction between electromagnetic work and Joule heating allows us to identify where and under what conditions the assumption that the neutral wind corotates with the Earth is not likely to be physically consistent with predicted Hall and Pedersen conductances.

Tuning Perovskites’ Hydration-Induced Chemical Expansion with Octahedral Tilt Angles

Tuning Perovskites’ Hydration-Induced Chemical Expansion with Octahedral Tilt Angles

The research on the effect of dynamic tilt variation on the phase of cold atomic gravimeter

In recent years, absolute gravity comparison experiments between cold atomic gravimeter and traditional gravimeter have been carried out by combining cold atomic gravimeter with stable platform. Due to the working characteristics of the stable platform, the tilt angle of the cold atomic gravimeter will change slightly in the process of dynamic measurement, and the measurement noise will be introduced. In order to improve the accuracy of dynamic measurement, this paper first analyzes the trajectory of the mirror and atom in the atomic gravimeter combined with carrier motion information, obtains the phase expression of the atomic interferometer using the translation and rotation matrix, evaluates the main terms of the gravity deviation using the 20-min navigation data on the ship in the South China Sea, and simplifies the higher-order small-terms in the main terms to deduce the simplified form of the gravity deviation. Then, the Fourier transform is used to transform the simplified expression into the power spectrum expression of phase noise, the corresponding noise sensitivity function is used in the form of trigonometric. The 20-min data is divided into 10 intervals, the root-mean-square (RMS) value of the overall gravity deviation is 1.5–3 mGal using the power spectrum of the platform angle, angular velocity and carrier acceleration in each interval. The variation fluctuation of the RMS value is consistent with the fluctuation of solving the gravity deviation through the trajectory. The conclusion provides the calculation method of gravity noise caused by dynamic tilt change and horizontal acceleration, and also provides the basis for platform design.

Aerodynamic and Structural Assessment of Floating Wind Turbine Rotor Under Varying Tilt Angle

Predicting the aerodynamic performance of floating offshore wind turbines (FOWTs) proves challenging due to platform motion induced by waves. The effect of wind and waves results in a six-degree-of-freedom motion of the platform, directly influencing turbine performance. Understanding the impact of specific degrees of freedom (DOF) motions on aerodynamics and structural response is crucial for effective wind turbine design. This research examines the impact of rotor tilt on both aerodynamic performance and structural response. The investigation employs computational fluid dynamics (CFD) analysis and mapping aerodynamic loads onto the finite element (FE) mesh for structural analysis. The study employs a comprehensive 3D simulation, utilizing the moving reference frame (MRF) method for the NREL 5 MW reference wind turbine CFD simulations. It explores different rotor tilt angles (5°, 10°, 15°, and 20°) encountered by offshore structures during their operation and examines their impact on aerodynamic performance. Predicted aerodynamic loads were mapped onto the blade FE mesh using the radial basis function (RBF) interpolation technique and solved using the open-source FE solver CalculiX. The analysis shows that the turbine performance is relatively unaffected up to a tilt angle of 10°. However, further increase in rotor tilt angle adversely impacts turbine performance, leading to notable reductions in thrust and power output. The fluid-structure coupled analysis provided insights into the deformations and stresses experienced by the turbine blade, indicating a notable increase in flap-wise displacement for larger tilt angles, while edge-wise displacement is not as significantly affected. The maximum stress location on the blade generally correlates well with actual observations.

Modeling the effects of starspots on stellar magnetic cycles

Context. Observations show that faster rotating stars tend to have stronger magnetic activity and shorter magnetic cycles. The cyclical magnetic activity of the Sun and stars is believed to be driven by the dynamo process. The success of the Babcock-Leighton (BL) dynamo in explaining the solar cycle suggests that starspots could play an important role in stellar magnetic cycles. Aims. We aim to extend the BL mechanism to solar-mass stars with various rotation rates and explore the effects of emergence properties of starspots in latitudes and tilt angles on stellar magnetic cycles. Methods. We adopt a kinematic BL-type dynamo model operating in the bulk of the convection zone. The profiles of the large-scale flow fields are from the mean-field hydrodynamical model for various rotators. The BL source term in the model is constructed based on the rotation dependence of starspot emergence; that is, faster rotators have starspots at higher latitudes with larger tilt angles. Results. Faster rotators have poloidal flux appearing closer to about ±55° latitudes, where the toroidal field generation efficiency is the strongest because of the peak in the strength of the latitudinal differential rotation there. It takes a shorter time for faster rotators to transport the surface poloidal field from their emergence latitude to the ±55° latitudes of efficient Ω-effect, which shortens their magnetic cycles. The faster rotators operate in a more supercritical regime because of a stronger BL α-effect relating to the tilt angles, which leads to stronger saturated magnetic fields and makes the coupling of the poloidal field between two hemispheres more difficult. The magnetic field parity therefore shifts from the hemispherically asymmetric mixed mode to quadrupole, and further to dipole when a star spins down. Conclusions. The emergence of starspots plays an essential role in the large-scale stellar dynamo.

Phase Transition near the Filling Factor ν = 3

A phase transition accompanied by the appearance of a spike in the longitudinal resistance of a two-dimensional electron system has been studied using the electron spin resonance near the filling factor ν = 3 in the ZnO/MgZnO heterojunction. This transition occurs when the tilt angle θ of the magnetic field is increased to some critical value θc. An analysis of the spin resonance amplitude has made it possible to demonstrate the spin nature of this phenomenon. For example, the ground state of the system on both sides of the transition has a nonzero spin polarization, which changes by several times when the phase of the system is changed. Strong spin resonance is observed both at θ < θc and at θ > θc. Surprisingly, the spin resonance at the critical angle θc has been detected in only one phase, which lies in the region of magnetic fields below the critical field Bc corresponding to the spike position in the longitudinal resistance. An increase in the magnetic field to this value leads to a decrease in the resonance amplitude and an increase in the resonance width. In the field region above Bc, the spin resonance disappears completely. Such behavior of the spin resonance is most likely due to the formation of domains with different spin polarizations in the electron system.

Wind farm modelling of tilted rotors

This study explores the benefits of tilted rotors in wind farms, focusing on a 3x3 grid of 10MW turbines and a 153-turbine farm modelled after the Hollandse-Kust West site with 15MW turbines. Computational Fluid Dynamics models ranging from mid to higher order, including FarmFlow (Parabolic RANS), TNO-VBM (RANS), and NREL-SOWFA (LES), were validated against CL-Windcon wind tunnel measurements.Comparisons between low and high-order CFD models reveal good agreement, with LES indicating increased wake mixing. Tilted rotor simulations align well, except for the lower-order model, deviating at extreme tilt angles. Positive tilts in a 3x3 farm result in a 10% increase in sub-rated wind farm yield and a 26% reduction in peak thrust loads during post-rated conditions. However, for larger wind farm clusters, tilting the rotors can increase the production of some parts within while its overall production is not increased. The investigated results depend on the tested scenario, thus further exploration is recommended.

A Synoptic View of Mantle Plume Shapes Enabled by Virtual Reality

AbstractThe shapes of mantle plumes are sensitive to mantle viscosity, density structure, and flow patterns. Increasingly, global tomographic models reveal broad plume conduits in the lower mantle and highly tilting conduits in the mid and upper mantle. Previous studies mostly relied on 2D slices to analyze plume shapes, but fully investigating the complexity of 3D plume structures requires more effective visualization methods. Here, we use immersive headset‐based virtual reality (VR) to visualize the full‐waveform global tomographic models SEMUCB‐WM1 and GLAD‐M25. We develop criteria for the identification of plume conduits based on the relationship between the plume excess temperature and the VS anomaly (δVS). We trace 20 major plume conduits, measure the offsets of the conduits in azimuth and distance with respect to the hotspots, calculate the tilt angle, and evaluate the δVS along all traced conduits. We compare our traced conduits with the conduits predicted by global mantle convection models and vertical conduits. The wavespeed variations along conduits traced from each tomographic model are slower than modeled or vertical conduits, regardless of which tomographic model they are evaluated in. The shapes of traced conduits tend to differ greatly from modeled conduits. Plume ponding and the emergence of secondary plumes, which could result from a combination of compositional variations, phase transitions, small‐scale convection, and variations in viscosity, can contribute to the complex observed plume shapes. The variation of δVS along the traced conduits and complex plume shapes suggest a thermochemical origin of many plumes.

How accurate are ultrasonic anemometers, calibrated in a laminar wind tunnel, under turbulent conditions?

Two ultrasonic anemometers, namely the Gill HS-100 and the Anemoment TriSonica Mini, were placed in the VKI L-1A wind tunnel to assess their accuracy and precision. A comparison was made between these instruments and a Prandtl probe, using a range of wind speeds up to 20 m/s, eighteen azimuth angles (wind directions) at 20° intervals, five tilt angles ranging from -10 to 10°, and two levels of turbulence. As the normal level of turbulence in the wind tunnel, determined by hot wire anemometry, is less than 1%, a grid was installed to allow a second level of turbulence of 6.1% to be evaluated. The analysis shows that the Gill HS-100 accurately measures wind speed in low turbulence conditions in accordance with the manufacturer’s specifications. However, in a turbulent atmosphere, the measured wind speeds are not only overestimated by 2-8% compared to the Prandtl probe but also show a systematic shift compared to the low turbulence case. As expected from the manufacturer’s specifications, the TriSonica Mini is less accurate and precise than the HS-100. In a low-turbulence environment, it fails to meet the manufacturer’s specifications. In a more turbulent atmosphere, however, it matches and even outperforms the HS-100, making it suitable for real-world applications. However, it did show reduced accuracy at non-horizontal wind angles, requiring careful consideration for drone-based measurements. More complex calibrations involving multiple turbulence levels could be considered for both anemometers. However, the feasibility of this approach remains uncertain in light of the results obtained.

Optimization of tilt angle for PV in China with long-term hourly surface solar radiation

The optimal tilt angle for photovoltaic (PV) systems is crucial for maximizing solar energy capture. China's diverse climate and geography pose challenges for tilt angle optimization. This study addresses the challenges by using a data-driven approach to determine grid-specific optimal tilt angles across China. Long-term ERA5 hourly solar radiation data and an optimization procedure are used to calculate the annual and monthly tilt angle that maximizes the total solar radiation received over different time periods (up to ten years) for every grid in China. Sensitivity analyses indicate that the optimized tilt angle varies by up to 10° depending on the time period considered, highlighting the importance of long-term radiation data. It is shown that four latitude-dependent schemes in China cannot accurately match the optimized tilt angles, emphasizing the need for optimization through the use of local solar radiation. The difference between our optimized tilt angles and ones via a best-performing latitude scheme makes for an estimated PV power loss of approximately 1.11 TWh/year based on China's PV installations in 2018, equivalent to the PV power generation of Philippines or Portugal in the same year. The presented data-driven framework contributes to China's PV industry by determination of optimal fixed tilt angles.

Pillar data-acquisition strategies for cryo-electron tomography of beam-sensitive biological samples.

For cryo-electron tomography (cryo-ET) of beam-sensitive biological specimens, a planar sample geometry is typically used. As the sample is tilted, the effective thickness of the sample along the direction of the electron beam increases and the signal-to-noise ratio concomitantly decreases, limiting the transfer of information at high tilt angles. In addition, the tilt range where data can be collected is limited by a combination of various sample-environment constraints, including the limited space in the objective lens pole piece and the possible use of fixed conductive braids to cool the specimen. Consequently, most tilt series are limited to a maximum of ±70°, leading to the presence of a missing wedge in Fourier space. The acquisition of cryo-ET data without a missing wedge, for example using a cylindrical sample geometry, is hence attractive for volumetric analysis of low-symmetry structures such as organelles or vesicles, lysis events, pore formation or filaments for which the missing information cannot be compensated by averaging techniques. Irrespective of the geometry, electron-beam damage to the specimen is an issue and the first images acquired will transfer more high-resolution information than those acquired last. There isalso an inherent trade-off between higher sampling in Fourier space and avoiding beam damage to the sample. Finally, the necessity of using a sufficient electron fluence to align the tilt images means that this fluence needs to be fractionated across a small number of images; therefore, the order of data acquisition is also a factor to consider. Here, an n-helix tilt scheme is described and simulated which uses overlapping and interleaved tilt series to maximize the use of a pillar geometry, allowing the entire pillar volume to be reconstructed asa single unit. Three related tilt schemes are also evaluated that extend the continuous and classic dose-symmetric tilt schemes for cryo-ET to pillar samples to enable the collection of isotropic information across all spatial frequencies. Afourfold dose-symmetric scheme is proposed which provides a practical compromise between uniform information transfer and complexity of data acquisition.

Agri-voltaics near airport facilities. Reconciling the risk of solar glare with power generation

The installation of photovoltaic systems on cultivated land enables both agricultural and green energy production simultaneously. The result is an efficient and inclusive use of land that promotes the rural economy, enables the recovery and maintenance of land and prevents its abandonment when it is considered not profitable. This intent is facilitated in semi-rural areas where there is already the presence of infrastructure connected to the national power grid, but at the same time is limited by other human activities. Runway approach and air traffic control operations impose very stringent constraints on the possibility that photovoltaic panels, reflecting solar radiation, may glare airport operators.This article provides a methodology for verifying such phenomena (control function) and mitigating them by maximizing solar power generation (objective function). Through a case study located in central Italy, positioned near an airport, it was possible to investigate the design variables to protect the landing air routes and the airport control tower.In this case study, with an azimuth angle of 47° and tilt angle of 25°, and thanks to a 5 m high tree screen placed on the edge of the land on which the agri-voltaic installation stands, it is possible to secure airport operations by eliminating all forms of solar glare. At the same time, 21.9 GWh of photovoltaic energy is produced annually, while avoiding the release of 8,773 tons of CO2 into the atmosphere. Compared with the optimal, unconstrained case, photovoltaic panels arranged in this way decrease their annual energy production by only 6.8 %.