Unfavorable Orientation Research Articles

Defining the ideal trajectory into the inner ear in image-guided cochlear implant surgery

The aim of robot-assisted cochlear implant surgery (RACIS) is to access the inner ear with minimal trauma. High-resolution imaging, empowered with a highly accurate navigation system can enable the planning of a direct keyhole drilling trajectory toward the inner ear. The time has come to (re)define the ideal trajectory into the inner ear with robot-assisted tools that can drill with the highest accuracy. The trajectories of past RACIS procedures were analysed to gain insight into how to calculate the most ideal trajectory and to determine which trajectory parameters influence the course of the procedure. Data-analysis was performed on three groups of previously performed RACIS-procedures. Group 1 included the RACIS-procedures with a round window (RW) approach. Group 2 included the RACIS-procedures with difficulty entering the inner ear. Group 3 included the converted cases to conventional CI surgery due to inadequate intra-operative safety margins. The RW diameter was significantly smaller and its orientation significantly less favourable in group 2 compared to group 1. A smaller surface size and an unfavourable orientation of the RW in relation to the drilling trajectory are thus associated with a more difficult electrode array insertion in RACIS. Both must be taken into account when planning a drilling trajectory into the inner ear.

Combined application of FTAN and cross-spectra analysis to ambient noise recorded by a microseismic monitoring network

A case study of seismic interferometry applied to a small microseismic monitoring network is here presented. The main objectives of this study are (i) to quantify the lateral variability of shear-wave velocities in the studied area, and (ii) to investigate the bias produced by noise directionality and non-stationarity in the velocity estimate. Despite the limited number of stations and the short-period character of the seismic sensors, the empirical Green’s functions were retrieved for all station pairs using two years of passive data. Both group and phase velocities were derived, the former using the widespread frequency-time analysis, the latter through the analysis of the real part of the cross-spectra. The main advantage of combining these two methods is a more accurate identification of higher modes, resulting in a reduction of ambiguity during picking and data interpretation. Surface wave tomography was run to obtain the spatial distribution of group and phase velocities for the same wavelengths. The low standard deviation of the results suggests that the sparse character of the network does not limit the applicability of the method, for this specific case. The obtained maps highlight the presence of a lower velocity area that extends from the centre of the network towards southeast. Group and phase velocity dispersion curves have been jointly inverted to retrieve as many shear-wave velocity profiles as selected station pairs. While the average model can be used for a more accurate location of the local natural seismicity, the associated standard deviations give us an indication of the lateral heterogeneity of seismic velocities as a function of depth. Finally, the same velocity analysis was repeated for different time windows in order to quantify the error associated to variations in the noise field. Errors as large as 4% have been found, related to the unfavorable orientation of the receiver pairs with respect to strongly directional noise sources, and to the very short time widows. It was shown that using a one-year time window these errors are reduced to 0.3%.

Determining technological parameters for obtaining ta15 titanium alloy blanks with improved mechanical characteristics using the electron-beam 3D printing method

The object of this study is the process of electron beam 3D printing of articles made of TA15 titanium alloy powder. Peculiarities of the structure and properties formation of alloy blanks, obtained by this method have been described. Influence of process parameters (electron beam power and geometric scanning parameters) on the characteristics of the material were considered. Step of displacement of the beam trajectory changed from 0.1 to 0.25 mm with an interval of 0.05 mm. Specific energy of the electron beam varied from 20 to 70 J/mm3 for every trajectory displacement step. The macrostructure was examined visually while the microstructure was studied by optical microscopy. Mechanical properties were determined by uniaxial tension and impact bending tests. It was established that depending on the 3D printing parameters the macrostructure of most samples is dense but with unfavorable parameters non-fusions or shrinkage porosity defects may form. The microstructure of the dendritic type has an α´+β lamellar-acicular morphology, its dispersity and shape of α´–phase areas vary depending on the process parameters. A scanning step of 0.2 mm and a beam energy of 40 J/mm3 allows obtaining a dispersed microstructure in which there are no non-fusions and shrinkage micropores. The value of the Rm is 27 %, and the R0.2 is 24 % higher than that of the alloy obtained by the conventional technology of electron beam melting. The A5 is 3.2 times higher. However, impact toughness of the sample with dendrite unfavorable orientation to the direction of load applying may be lower compared to conventional technology. The results could be used for devising commercial technology of high strength titanium alloys parts produced by 3D printing

Complementary In Situ Characterization of Superelasticity in Fe–Mn–Al–Ni–Ti Shape Memory Alloys by Acoustic Emission, Digital Image Correlation and Infrared Thermography

AbstractCoupled in situ investigations were conducted on a Fe–Mn–Al–Ni–Ti single crystal deformed in compression and two Fe–Mn–Al–Ni–Ti oligo-crystals deformed in tension. Acoustic emission measurements were employed to monitor the degradation of superelasticity and the stabilization of martensite due to dislocation processes. These observations were corroborated by the application of digital image correlation and infrared thermography measurements. A poor strain reversibility and a premature plastification of the parent phase were observed in case of the single crystal due to an unfavourable crystal orientation. A contradictory transformation behaviour of the two oligo-crystals was observed, with one specimen showing a promising strain reversibility and characterisitic signs of degradation, and the other specimen exhibiting a limited strain reversibility due to an unusual confinement of the martensitic phase transformation to an unfavourably oriented grain. In the former case, an increase in the dislocation density within five cycles was detected through a shift of the acoustic signals’ median frequencies. In the latter case, a strong coupling between martensite nucleation and dislocation generation led to a pronounced martensite stabilization after one loading cycle. For all specimens, temporal sequence effects related to the coupling of martensite nucleation and dislocation generation were detected by means of acoustic emission.

Influence of orientation-dependent lath martensite yielding on the hardening behavior of quenched martensitic steels

The onset of plasticity in quenched martensitic microstructures is characterized by a low initial yield stress, extreme initial hardening, and sudden saturation. The existing literature attributes these phenomena to residual stresses or microstructural heterogeneities. We introduce a novel perspective, suggesting that orientation-dependent yielding of lath martensite, induced by inter-lath sliding, significantly contributes to the observed behavior. To support this, we employ a numerical microstructural model, considering the yielding anisotropy of martensite packets due to sliding along their habit plane orientation. The combined response of early yielding in martensite packets with a favorable habit plane, along with those initially remaining elastic due to an unfavorable orientation, results in a macro-scale behavior with a low initial yield stress, followed by substantial initial hardening until the saturation stress level is approached. The simulations also qualitatively capture other observations reported for quenched martensitic steels, e.g. the effect of carbon content.

Laboratory Tests of Large-Scale Block Models on the Load Transfer and Failure Mechanisms of Rock Masses Subjected to Anchor Loading

This paper presents a laboratory testing rig designed to investigate the failure mechanisms and load transfer of rock masses under rock anchor loading. The study revealed that joint patterns significantly affect the strength and capacity of the rock mass, with existing design approaches based on apex angles of 90∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{\\circ }$$\\end{document} or 60∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{\\circ }$$\\end{document} found to be potentially overly conservative. Joint orientation and spacing should be included in the anchor design to obtain a more precise design criterion. In all the studied patterns, increasing the horizontal and vertical stress increased the block models’ capacity, and load arching did not occur in the model with an unfavourable joint orientation. This study also revealed that the failure surface followed the joints in all tests and that the block model capacity was significantly higher than estimated with the design principle based on the weight of the overlying rock. The findings of this work have important implications for designing rock anchoring systems in mining and civil engineering demonstrate that joint orientation and block size significantly affect the rock mass capacity. This study confirms the need to consider the influence of in situ stresses on rock mass capacity when designing of rock anchors. Overall, this work guides the development of more precise design criteria for rock anchors, contributing to more efficient and effective rock engineering practices.

Quasi-plastic deformation mechanisms and inverse Hall–Petch relationship in nanocrystalline boron carbide under compression

Abstract Grain boundaries (GBs) play a significant role in the deformation behaviors of nanocrystalline ceramics. Here, we investigate the compression behaviors of nanocrystalline boron carbide (nB4C) with varying grain sizes using molecular dynamics simulations with a machine-learning force field. The results reveal quasi-plastic deformation mechanisms in nB4C: GB sliding, intergranular amorphization and intragranular amorphization. GB sliding arises from the presence of soft GBs, leading to intergranular amorphization. Intragranular amorphization arises from the interaction between grains with unfavorable orientations and the softened amorphous GBs, and finally causes structural failure. Furthermore, nB4C models with varying grain sizes from 4.07 nm to 10.86 nm display an inverse Hall–Petch relationship due to the GB sliding mechanism. A higher strain rate in nB4C often leads to a higher yield strength, following a 2/3 power relationship. These deformation mechanisms are critical for the design of ceramics with superior mechanical properties.

Effective In Situ Alkoxide Trapping by TMSX in the Presence of TPP Catalyst in Glycidol Acetal Rearrangements.

This study demonstrates a nucleophile-catalyzed, trimethylsilyl halide-promoted rearrangement reaction of glycidol acetals to form halogenated cyclic acetals. The acetal group has been activated selectively in the presence of trimethylsilyl cation, which is used as in situ-generated alkoxide trapping reagent. Nucleophilic chloride and bromide ions participate in addition reactions with epoxides predominantly via SN1-type epoxide opening, while non-nucleophilic iodide and triflate ions induce a positive charge at the epoxide carbon. A systematic investigation of acetal-initiated polyene cyclization of epoxy polyenes has been conducted using bicyclic epoxonium ions as transient intermediates. Unfavorable orbital orientation and other stereoelectronic factors hinder the much-anticipated polyene cyclizations. The potential of this method has been showcased through its application in the total synthesis of parvistone A, a chlorinated styryllactone.

Investigation of microstructural and mechanical properties of weld lines in injection‐molded short glass fiber‐reinforced polyamide 6

AbstractThis research investigates the impact of weld lines on the mechanical properties and fracture behavior of injection‐molded unfilled and glass fiber‐reinforced polyamide 6 (PA6). The study aims to predict the weld line strength by analyzing the composite's microstructure at the weld line and investigating the influence of injection molding parameters. While weld lines had minimal effects in unfilled PA6 thanks to the matrix's high healing capability, composite samples showed reduced mechanical properties due to unfavorable fiber orientation at the weld line. Fracture surfaces revealed a bell‐shaped structure linked to the ‘underflow’ process caused by flow imbalances during injection molding. This phenomenon impacts fiber orientation at the weld line, affecting mechanical properties. The ‘underflow’ is simulated using Autodesk Moldflow®, predicting enhanced fiber alignment along the flow direction. Regarding processing parameters, both melt and mold temperatures showed negligible impacts, while enhanced mechanical properties were observed at elevated packing pressures. The analysis of fracture surfaces showed intensified “underflow” with increased packing pressure. A relationship is established between weld line strength and fiber orientation at the weld line, potentially serving as a predictive tool for estimating weld line strength.Highlights Weld lines in unfilled PA6:Negligible impact on the mechanical properties. In the PA6 composite: significant drop due to unfavorable fiber orientation. Fracture behavior of the composite: Bell‐shaped weld line linked to “underflow.” Melt and mold temperature: minor effect; packing pressure enhances properties. Correlation established between the weld line strength and fiber orientation.

Effects of grain boundaries and quasi-plastic deformation in shocked bi-crystal boron carbide nanopillars

Grain boundaries (GBs) significantly affect the mechanical properties of ceramics, but they are understudied. Here, we employ three bi-crystal boron carbide nanopillars to investigate the effect of GBs on the shock behaviors and deformation mechanisms of B4C, using molecular dynamics simulations with a reactive force field. The results reveal a strong correlation among the shock behaviors, interfacial energies, and grain orientations. The (11¯02)/(1¯101) model with the highest interfacial energy model shows intragranular amorphization due to the interaction between the softened GB and the unfavorable orientation of the grain, while the other two GB models experience intergranular amorphization. Furthermore, the quasi-plastic behaviors in the three models arise from GB rotation or GB sliding. The US-UP relationships of quasi-plastic waves exhibit a bilinear relationship due to the intergranular amorphization formation. Noteworthy, this bilinear behavior for the (11¯02)/(1¯101) model displays a second kink, corresponding to the formation of intragranular amorphization. This study serves as a reference for designing ceramics with superior properties.

Research on Collapse Risk Assessment of Karst Tunnels Based on BN Self-Learning

The high risk of collapse is a key issue affecting the construction safety of karst tunnels. A risk assessment method for karst tunnel collapse based on data-driven Bayesian Network (BN) self-learning is proposed in this study. The finite element calculation is used to analyze the distribution law of the plastic zone of the tunnel and the karst cave surrounding rock under different combinations of parameters, and a four-factor three-level data case database is established. Through the self-learning of the BN database, a Bayesian Network model of karst tunnel collapse risk assessment with nodes of four types of karst cave parameters is established. The specific probability distribution state and sensitivity of the parameters of different types of karst caves under the condition of whether the tunnel and the karst cave plastic zone are connected or not are studied. The research results show that the distance and angle of the karst cave are the main influencing parameters of the tunnel collapse probability, and the diameter and number of the karst cave are the secondary influencing parameters. Among them, the distance, diameter, and number of karst caves are proportional to the probability of tunnel collapse, and the most unfavorable orientation of karst caves is 45° above the tunnel. When the tunnel passes through the karst area, it should avoid the radial intersection with the karst cave at the arch waist while staying away from the karst cave. The results of this work can provide a reference for the construction safety of karst tunnels under similar conditions.

Preclinical Efficacy of Cabazitaxel Loaded Poly(2-alkyl cyanoacrylate) Nanoparticle Variants.

Biodegradable poly(alkyl cyanoacrylate) (PACA) nanoparticles (NPs) are receiving increasing attention in anti-cancer nanomedicine development not only for targeted cancer chemotherapy, but also for modulation of the tumor microenvironment. We previously reported promising results with cabazitaxel (CBZ) loaded poly(2-ethylbutyl cyanoacrylate) NPs (PEBCA-CBZ NPs) in a patient derived xenograft (PDX) model of triple-negative breast cancer, and this was associated with a decrease in M2 macrophages. The present study aims at comparing two endotoxin-free PACA NP variants (PEBCA and poly(2-ethylhexyl cyanoacrylate); PEHCA), loaded with CBZ and test whether conjugation with folate would improve their effect. Cytotoxicity assays and cellular uptake of NPs by flow cytometry were performed in different breast cancer cells. Biodistribution and efficacy studies were performed in PDX models of breast cancer. Tumor associated immune cells were analyzed by multiparametric flow cytometry. In vitro studies showed similar NP-induced cytotoxicity patterns despite difference in early NP internalization. On intravenous injection, the liver cleared the majority of NPs. Efficacy studies in the HBCx39 PDX model demonstrated an enhanced effect of drug-loaded PEBCA variants compared with free drug and PEHCA NPs. Furthermore, the folate conjugated PEBCA variant did not show any enhanced effects compared with the unconjugated counterpart which might be due to unfavorable orientation of folate on the NPs. Finally, analyses of the immune cell populations in tumors revealed that treatment with drug loaded PEBCA variants affected the myeloid cells, especially macrophages, contributing to an inflammatory, immune activated tumor microenvironment. We report for the first time, comparative efficacy of PEBCA and PEHCA NP variants in triple negative breast cancer models and show that CBZ-loaded PEBCA NPs exhibit a combined effect on tumor cells and on the tumor associated myeloid compartment, which may boost the anti-tumor response.

Numerical simulation of microstructure evolution in molten pool of nickel-based superalloy during selective laser melting

The competitive growth and the evolution of grain/dendrite structures of IN718 superalloy in the molten pool during selective laser melting (SLM) were investigated with the finite element method (FEM) coupling the phase-field model (PFM). The thermal evolution was solved by the FEM and then the results were input into the PFM model to simulate the microstructure evolution involving grain nucleation, grain epitaxial growth and grain competition. Based on the analysis of microstructure evolution of the transverse and longitudinal sections of the molten pool, the mechanism of dendrite competitive growth in the SLM process was discussed and the concentration distribution of the solute element Nb in the molten pool was quantitatively calculated. The results show that the dendrite competitive growth is affected by both the temperature gradient and the crystallographic orientation. The unfavorable orientation grain with a high misorientation (>22.5°) will be eliminated by the favorable orientation grain quickly.

Dynamic Rupture of the 2021 MW 7.4 Maduo Earthquake: An Intra‐Block Event Controlled by Fault Geometry

AbstractThe 2021 MW 7.4 Maduo event occurred within the Bayan Har block in eastern Tibet, which provides an opportunity to investigate the stress conditions and rheology of faults within the block. Here, we perform dynamic rupture simulations based on the finite element method to explore the physical conditions underlying this earthquake and the factors that controlled the rupture process. We construct the model with a nonplanar fault inferred from the Interferometric Synthetic Aperture Radar (InSAR) data and aftershocks sequence relocation. Our dynamic model is controlled by slip‐weakening friction law with initial stress on fault resolved from a uniform regional stress field. The preferred model produces an average slip of ∼2.2 m with a maximum slip of ∼4.0 m. There are three asperities distributed along the strike, which have captured the main features of the Maduo event. The simulation results are consistent with the static GPS coseismic surface displacements, InSAR data, and displacement waveforms recorded by high‐rate GNSS stations. By comparing the results with the planar fault model and rotated stress fields, we find that the fault geometry and regional stress field are the primary factors that control the rupture process of the event. Moreover, we infer that the unfavorable orientation and fault bend lead to minor slips on the branch fault. Furthermore, we investigate the potential mechanisms of supershear rupture on the eastern fault segment.

C2 Superior Facetal Osteotomy: A Novel Technique in Complex Craniovertebral Junction Surgery for C1 Lateral Mass Screw Placement.

Complex craniovertebral junction (CVJ) defects account for a considerable proportion of CVJ diseases. Given the heavily assimilated C1, an unfavorable C1-C2 joint orientation, an overriding C2 superior facet, a low-hanging occiput, and an abnormal vertebral artery course with a high-riding vertebral artery, placement of C1 lateral mass screws might be difficult. To address this, a novel technique for placing C1 lateral mass screws that avoid vertebral artery injury, low-hanging occiput, and overriding C2 superior facet was developed in this study. This approach enables firm fixation of C1-C2 even in difficult situations where the placement of the C1 lateral mass is challenging.

Large gravitational collapse structure on a rocky coast (Kvarner, NE Adriatic Sea)

The studied rock collapse structure is located on the Liburnian coast (Rijeka Bay, channel zone of the NE Adriatic). The relief of the southern part of this coast, with a length of 6.5 km, is a large escarpment with very steep to vertical slopes reaching heights of 100 m above sea level, as a result of tectonic movements along the Kvarner fault zone. These events probably led to a sudden relaxation of the highly fractured rock mass. The progressive expansion occurred at locations where previously favourably oriented faults and fissures had formed a polygonal rock collapse resembling a rock-slide which is the focus of this study. Another aim of this study is to reconstruct and explain the complex morphological evolution of the studied landslide, from the pre-failure deformations, through the failure itself, to post-failure displacements, as well as possible future instabilities. Recent techniques to survey the instability, location and to analyse the evolution of the rupture surface and its dimensions were combined (Unmanned Aerial Vehicle, Side Scan Sonar and Remotely Operated Vehicles). The estimated total volume of displaced rock mass is 950,000 m3. The lower part of the instability phenomenon was submerged during the Holocene sea level rise. Since then, a large part of the displaced rock mass has been in a stable position, with sporadic rock falls. However, given unfavourable orientation and discontinuity characteristics, as well as unfavourable environmental influences, possible instabilities might also be expected in the future.

Highly Stable and Efficient Formamidinium-Based 2D Ruddlesden-Popper Perovskite Solar Cells via Lattice Manipulation.

Formamidinium (FA)-based 2D perovskites have emerged as highly promising candidates in solar cells. However, the insertion of 2D spacer cations into the perovskite lattice concomitantly introduces microstrain and unfavorable orientations that hinder efficiency and stability. In this study, by finely tuning the FA-based 2D perovskite lattice through spacer cation engineering, a stable lattice structure with balanced distortion, microstrain relaxation, and reduced carrier-lattice interactions is achieved. These advancements effectively stabilize the inherently soft lattice against light and thermal-aging stress. To reduce the photocurrent loss induced by undesired crystal texture, a polarity-matched molecular-type selenourea (SENA) additive is further employed to modulate the crystallization kinetics. The introduction of the SENA significantly inhibits the disordered crystallization induced by spacer cations and drives the templated growth of the quantum well structure with a vertical orientation. This controlled crystallization process effectively reduces crystal defects and enhances charge separation. Ultimately, the optimized FA-based perovskite photovoltaic devices achieve a remarkable power conversion efficiency (PCE) of 20.03% (certified steady-state efficiency of 19.30%), setting a new record for low-n 2D perovskite solar cells. Furthermore, the devices exhibit less than 1% efficiency degradation after operating at maximum power point for 1000 h and maintain excellent stability after thermal aging and cycles of cold-warm shock, respectively.

A comprehensive performance evaluation methodology for sea-crossing cable-stayed bridges under wind and wave loads

This study proposes a probabilistic performance evaluation framework for sea-crossing cable-stayed bridges (SCBs) subjected to wind and wave excitations with the incorporation of wind speed and direction, bridge orientation, wind-wave correlation and parameter uncertainties. Both the bridge serviceability and safety are taken into account in the performance assessment. The fragility analysis of the SCB under wind and wave loads is conducted using the wind-wave correlation model constructed based on field data. The actual damage probability of a local SCB is computed by combining the fragilities of bridge under different wind incidence angles with the copula-based joint probability distribution (JPD) of wind speed and direction, which is developed using the wind field data recorded in Lianyungang city of China from 1971 to 2020. The results show that under the defined wind incidence angle of 0°, the exemplar SCB suffers the highest fragility. Moreover, with the data-based occurrence probability model of wind and wave hazards, the damage probabilities under all possible wind speeds and directions are computed; then the optimal and most unfavorable orientations of the SCB are obtained. This investigation provides a comprehensive and practical method for the performance evaluation and design optimization of SCBs under wind and wave loads with long-term recorded hazard data at the local site.

Texture evolution and serrated failure of AZ31B alloy subjecting to equal channel angular extrusion

Equal channel angular extrusion (ECAE) is considered the most promising method for improving strength and ductility. The microstructures after ECAE have been extensively studied for Mg alloys relating to mechanical properties. However, the changes in texture and their relationship with the prior conditions, extrusion conditions and extrusion directions are rarely studied. In the current work, the changes in texture of AZ31B Mg alloys were investigated along the normal direction (ND), transverse direction (TD), and rolling direction (RD) after ECAE processing one pass. The results revealed a rule that the AZ31B alloy follows for texture changes, where the basal texture (namely the focused c-axis) orients 45º or nearly orients 45º, regardless of the pre-extrusion texture, extrusion temperature, and extrusion rate. Interestingly, serrated failure sorely occurs along the ND for all extrusion conditions, due to the basal slip in an unfavorable orientation and the shear plane not parallel to either pyramidal slip directions.

Dithieno[3,2-f:2',3'-h]quinoxaline-Based Photovoltaic-Thermoelectric Dual-Functional Energy-Harvesting Wide-Bandgap Polymer and its Backbone Isomer.

Both organic solar cells (OSCs) and organic thermoelectrics (OTEs) are promising energy-harvesting technologies for future renewable and sustainable energy sources. Among various material systems, organic conjugated polymers are an emerging material class for the active layers of both OSCs and OTEs. However, organic conjugated polymers showing both OSC and OTE properties are rarely reported because of the different requirements toward the OSCs and OTEs. In this study, the first simultaneous investigation of the OSC and OTE properties of a wide-bandgap polymer PBQx-TF and its backbone isomer iso-PBQx-TF are reported. All wide-bandgap polymers form face-on orientations in a thin-film state, but PBQx-TF has more of a crystalline character than iso-PBQx-TF, originating from the backbone isomeric structures of α,α '/β,β '-connection between two thiophene rings. Additionally, iso-PBQx-TF shows inactive OSC and poor OTE properties, probably because of the absorption mismatch and unfavorable molecular orientations. At the same time, PBQx-TF exhibits both decent OSC and OTE performances, indicating that it satisfies the requirements for both OSCs and OTEs. This study presents the OSC and OTE dual-functional energy-harvesting wide-bandgap polymer and the future research directions for hybrid energy-harvesting materials.