Transverse Direction Research Articles

Anisotropic Heat Conduction of Silicon Nanocube through Strain Gradient Engineering.

Precise control of directional heat flow is essential for advancing applications such as microchip cooling and building thermal regulation. However, existing methods often face challenges related to manufacturing complexity, structural instability, and limited reversibility. Here, we present strain-gradient-induced crystal symmetry breaking as an effective strategy to achieve anisotropic heat conduction. We model a uniaxially bent silicon nanocube and predict an anisotropy ratio of 1.20 at a strain gradient of 0.44%/nm (12% bending strain). This anisotropy arises from two distinct types of strain within the bent lattice: static strain along the axial direction, which significantly impedes heat conduction, and dynamic strain in the transverse directions, which poses a minimal effect on heat flow. The static strain broadens the phonon spectrum and induces phonon overdamping, thereby enhancing scattering and leading to marked reductions in the thermal conductivity. These findings highlight strain-gradient-induced phonon spectrum engineering as a reversible and robust method for directional thermal regulation.

Improved Analytical model for mesh stiffness of helical gears considering the relationship of friction and flash temperature under steady temperature field

Abstract In the transmission process, thermal deformation of gears due to external factors, coupled with the thermal expansion of the tooth profile induced by flash temperature from surface friction, significantly impacts the time-varying mesh stiffness (TVMS) characteristics. Therefore, this paper proposes a novel analytical model for the TVMS of helical gears that considers these factors. In this model, the thermal deformation of gear foundation under a bulk temperature field is first determined using the displacement method. Blok's theory is then applied to establish the relationship between tooth surface friction and flash temperature, leading to the derivation of the actual tooth profile expansion equation under steady-state conditions. After that, based on this equation and considering the friction force in tangential, radial, and axial directions, the gear tooth and foundation stiffness of helical gear in transverse and axial directions under steady-state temperature field are accurately established. Finally, the proposed model is obtained by coupling each stiffness. By comparing with the FE result, the model is validated, and the influence of friction coefficient, bulk temperature, and gear parameters on TVMS is studied. The analytical model and findings provide valuable insights for optimizing gear parameter design.

Effect of keyhole and lack-of-fusion pores on the anisotropic microstructure and mechanical properties of PBF-LB/M-produced CuCrZr alloy

Abstract Due to the high reflectance and heat conductivity of copper and its alloys, the processing window for laser-based powder bed fusion (PBF-LB/M) processing of high-density copper components fundamentally overlaps with conduction and keyhole melting zones, resulting in the emergence of certain pores in the structure of printed parts. The present research aims to study how the development of process-induced lack-of-fusion or keyhole porosities during the PBF-LB/M process can affect the anisotropic microstructure and mechanical properties of the produced copper alloys. For this purpose, several samples were produced utilizing a similar CuCrZr-feedstock composition but varied process parameters from different areas of the PBF-LB/M processing window, specifically at laser powers of 300 W and 380 W which define the boarders of the conduction and keyhole regimes. X-ray computed tomography (XCT) revealed that the 300-W and 380-W samples achieved relative densities of 98.88% and 99.99%, respectively, with elongated lack-of-fusion pores forming at 300 W and semi-spherical keyhole pores at 380 W. Microstructural analyses employing scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) demonstrated strong anisotropy in different build directions of the samples, owing to the growth of long columnar grains with intense < 101 > orientation along the build directions. Here, the emergence of different types of pores can cause competition between the epitaxial growth of columnar grains and the heterogeneous nucleation of new grains on the layers’ interfaces, thereby significantly varying the grain size, preferred orientation, crystallographic texture, and microstructural anisotropy of the samples. Furthermore, compression tests and nanoindentation measurements of the printed alloys in the longitudinal and transverse directions revealed that the 300 W and 380 W samples exhibited compressive strength anisotropies of 0.061 and 0.072, and average nanoindentation hardness values of 1.3 GPa and 1.5 GPa, respectively. The orientation of elongated lack-of-fusion porosities perpendicular to the loading axis was identified as the most damaging factor, significantly reducing mechanical performance compared to the uniformly distributed keyhole pores.

In-situ experimental investigation of the small fatigue crack behavior in CP-Ti: The influence of loading parameters and directions

This study quantitatively investigates the influence of loading parameters and directions on the behavior of small fatigue cracks (SFC) in commercially pure titanium (CP-Ti). It is observed that reductions in peak stress and increases in stress ratio correlate with a decrease in SFC growth rate and an intensification of growth rate fluctuations. Notably, crack growth along the transverse direction (TD) generally exhibits lower rates compared to that along the rolling direction (RD), with more pronounced fluctuations. Through metallographic analysis of crack paths, roughness-induced crack closure (RICC) is identified as a significant factor contributing to the observed variations in SFC growth behavior under different loading conditions. Furthermore, electron backscatter diffraction (EBSD) characterization reveals that crack propagation along the RD is primarily governed by prismatic slip, while TD samples exhibit more engagement of non-prismatic slip systems with higher activation stress. This results in a more tortuous crack path and pronounced crack arrest phenomena. Finally, a modified multi-scale rate prediction model based on the reference stress ratio method is proposed. Comparative analysis demonstrates that the modified model outperforms existing models by offering enhanced predictive capability across diverse loading conditions, thereby reinforcing its robustness in predicting SFC behavior of CP-Ti.

Laminar flow of charged quantum fluids of the Calogero–Sutherland universality class

The effective field theory of the Calogero–Sutherland model represents a universality class of quantum hydrodynamic fluids in one spatial dimension. It describes quantum compressible fluids involving both chiralities in which the chiral density field obeys the quantum Benjamin–Ono equation. An extension of this theory to describe a laminar flow of the Calogero–Sutherland fluids in a rectangular geometry with small transverse width and the topology of a ribbon, is considered here. The physical picture is based on the edge states in the hierarchical quantum Hall effect, which may be seen as a collection of parallel one-dimensional quantum incompressible fluids moving along but confined within the transverse microscopic width of the edge of the sample. The effective theory is thus defined as the direct product of two one-dimensional theories of the Calogero–Sutherland class so that one involves motion while the other is confining. Charge transport may be induced by coupling the system to an external electromagnetic field that yields a global translation of the ground state. The effective theory describes quantum solitonic excitations along the direction of the flow and possesses a two-dimensional electric current density which shows a Wigner semicircle law profile in the transverse direction, suggesting a Poiseuille-like behavior but without dissipative viscous effects since the velocity of the fluid is not a well-defined quantum field. This simple physical picture predicts interesting phenomena with distinctive signatures that may be tested in real samples.

Lamotrigine promotes reentrant ventricular tachycardia in murine hearts.

In 2021, the US Food and Drug Administration issued a safety warning concerning lamotrigine use in patients with underlying cardiac disorders. This warning was based on invitro data that predicted class Ib antiarrhythmic activity for lamotrigine. Therefore, we investigated the proarrhythmic potential of lamotrigine in the murine heart and compared its effect with flecainide. Murine hearts were perfused with clinically relevant concentrations of lamotrigine 3.8 μg/mL (15 μmol·L-1) or flecainide .4 μg/mL (1 μmol·L-1). Ex vivo electrocardiography revealed a high prevalence of ventricular tachycardia (VT) in lamotrigine-perfused hearts (7/9 hearts), whereas only two hearts exposed to flecainide evidenced VT. Optical voltage mapping showed that lamotrigine preferentially decreased ventricular conduction velocity (CV) in the longitudinal direction at all pacing frequencies tested (-22% ± 8.6%, -30% ± 15.4%, and -33% ± 13.3% for pacing frequency of 200-ms, 180-ms, and 150-ms cycle length, respectively, p ≤ .05) compared to the transverse direction, which only slowed CV at the fastest pacing frequency (-15% ± 16% for pacing frequency of 150-ms cycle length, p ≤ .01). Notably, the preferential CV slowing in the longitudinal direction altered the anisotropic ratio, giving rise to a functional substrate for reentrant VT. In contrast, flecainide slowed CV uniformly in both longitudinal and transverse directions (-30% ± 8.5% vs. -27% ± 5.3%, -32% ± 9.4% vs. -29% ± 6.9%, and - 29% ± 8.3% vs. -27% ± 10% for pacing frequency of 200-ms, 180-ms, and 150-ms cycle length, respectively, p ≤ .05). Our findings provide mechanistic insight into the proarrhythmic impact of lamotrigine.

Seismic Response of Tunnels Under Effect of Overburden Depth Using Simplified Pseudo-Static Analysis

Earthquakes are one of the natural occurrences that can lead to massive disasters, either on structures or infrastructure. The seismic response and performance of underground infrastructure such as tunnels against earthquake vibrations is predictably severe due to the complex interaction between tunnels and the surrounding soil, especially one embedded in poor soil material properties. In view of this, previous experiences of tunnel damages subjected to earthquake loads have been reported in the literature. Thus, rigorous analysis is necessary to provide indepth knowledge and understanding of the seismic response of tunnels which beneficial to engineering practitioners in especially in early design stage in order to avoid the future risk of tunnel damage and failure during an unpredictable earthquake event. The aim of this study is to investigate the effect of overburden depth on seismic response of tunnels using the simplified pseudo-static analysis, while simultaneously to emphasize the shortcoming of conventional closed-form solution. This study presents a two-dimensional (2D) simplified pseudo-static analysis of soil-tunnel model embeded at 10m and 20m overburden depth subjected to increasing levels of seismic intensity at the transverse direction of tunnel axis. The numerical investigation was performed using the finite element program PLAXIS 2D. The circular shaped tunnel lining are assumed to be elastic, while the soil is considered as homogeneous, and isotropic in plane strain condition. Considering the complex soil-tunnel interaction, the tunnel lining and soil interface is assumed as no-slip condition. The numerical result of pseudo-static analyses were compared with the conventional closed-form Wang‘s analytical solution to verify the reliability of the obtained results. The results denoted that the tunnel embedded at 10m overburden depth experienced considerable seismic-induced deformation and structural forces than tunnel buried at 20m depth. The deformation and seismic induced structural forces of tunnel increased with increment on the magnitude of earthquake loadings. Thus, it can be concluded that the shallow tunnel suffered more damages compared to the tunnel embedded at deeper depth. Overburden depth of tunnel plays a significant role in modifying the seismic response of tunnel apart of the imposed magnitude of earthquake loadings. The conventional closed-form analytical method tends to overestimate the seismic response of tunnel compared to numerical pseudo-static analysis.

Geometry of Carrollian stretched horizons

Abstract In this paper, we present a comprehensive toolbox for studying Carrollian stretched horizons, encompassing their geometry, dynamics, symplectic geometry, symmetries, and corresponding Noether charges. We introduce a precise definition of ruled stretched Carrollian structures (sCarrollian structures) on any surface, generalizing the conventional Carrollian structures of null surfaces, along with the notions of sCarrollian connection and sCarrollian stress tensor. Our approach unifies the sCarrollian (intrinsic) and stretched horizon (embedding) perspectives, providing a universal framework for any causal surface, whether timelike or null. We express the Einstein equations in sCarrollian variables and discuss the phase space symplectic structure of the sCarrollian geometry. Through Noether's theorem, we derive the Einstein equation and canonical charge and compute the evolution of the canonical charge along the transverse (radial) direction. The latter can be interpreted as a spin-2 symmetry charge.

Our framework establishes a novel link between gravity on stretched horizons and Carrollian fluid dynamics and unifies various causal surfaces studied in the literature, including non-expanding and isolated horizons. We expect this work to provide insights into the hydrodynamical description of black holes and the quantization of null surfaces.

New Innovations in Precast Concrete Pavement

The need for rapid, long-lasting, sustainable concrete pavement rehabilitation strategies has never been greater for our ageing highway system. Work windows for pavement reconstruction and rehabilitation are often as little as 4-5 hours, limiting the options available for concrete pavement rehabilitation techniques. Recently, the California Department of Transportation (Caltrans), District 4, broke tradition from their traditional approach of concrete pavement rehabilitation by using prestressed precast concrete pavement to rehabilitate an existing concrete pavement on a very heavily travelled highway in the San Francisco Bay Area. The project incorporated a prestressed concrete pavement (PPCP) on a large scale. While the use of precast prestressed concrete pavement is not a new idea, some new innovations were incorporated into this project. These innovations included the use of two-way pretensioning (longitudinal and transverse directions), elimination of stressing pockets in the surface of the pavement, use of multi-strand post-tensioning ducts, and use of longer single-lane panels ranging in length from 5.5 to 11 m (18 to 36 ft). This paper discusses the development and deployment of precast prestressed concrete pavement technology on this project, including fabrication and installation issues, as well as challenges encountered throughout the project.

Quantifying Effective Built-in Temperature Difference for Decades- Old Jointed Plain Concrete Pavements in Eastern Washington State

Fifteen Portland cement concrete (PCC) slabs from four Jointed Plain Concrete Pavement (JPCP) sections in the Long-Term Pavement Program (LTPP) located in eastern Washington State were studied in this paper. Dipstick-measured transverse deflection profile along with temperature measurements across slabs’ depths collected during falling weight deflectometer (FWD) testing were used in the study. The youngest section in the study was 24 years old at the time of testing. The objective was to characterize the total effective linear temperature difference (TELTD) and the effective built-in temperature difference (EBITD) in the slabs. EBITD is a temperature differential representing the combined effects of construction built-in, as well as long-term drying shrinkage, and creep equivalent temperature differences. Using ISLAB2000, several iterations were run for each slab to identify the TELTDs that would produce slab curvatures close to those measured in the field. For validation purposes, the found TELTDs were used in Westergaard’s closed-form solution for deflections in the transverse direction. Transverse profiles predicted by ISLAB2000 and Westergaard equations matched well. EBITD, was then obtained by simply subtracting the in-field measured temperature differential from TELTD. Variations of EBITDs were found among the four sections, ranging from +31 to -120 °C (55 to -215 °F). Multiple factors, such as structural features, material properties, construction conditions, and climatic conditions, were identified as influential for the predicted EBITDs.

Experiences Resulted from Construction of Two-way Post-Tensioned Concrete Pavement

In this paper there are presented results of experimental investigation and preliminary conclusions dealing with the efficiency of early posttensioning concrete pavement. Short section of concrete pavement 3.5 by 20.0 m (11.5 by 65.6 ft) thickness 0.23 m (9 in.) was posttensioned in longitudinal and transverse direction. The total prestressing was realized in one stage after 48 hours from concreting. The unbonded tendons 75 mm (0.6 in.) were tensioned with 200 kN (45 kip) force in both direction. The aim of investigation was the experimental evaluation of temperature and concrete strains distributions during the process of pavement concrete hardening for different environmental condition for period of 13 months. Values of prestressing force distribution were monitoring for 26 days period. For this reason, unbonded tendons were equipped with vibrating wire force transducer Geokon type. The concrete strains as well as temperature changes were recorded with Geokon vibrating wire sensors localized at three levels of the slab thickness in four vertical cross-section.

Pedagogical study of the image of a magnetic dipole in front of a superconducting sphere

Abstract The method of images to solve certain electrostatic boundary-value problems is taught worldwide in undergraduate-level physics courses. Though it is also possible to employ this technique for solving magnetostatic boundary value problems, examples of this usage are rarely found in textbooks or physics pedagogy literature. In particular, the problem of finding the field due to a magnetic dipole kept in front of a superconducting sphere is an interesting one, because (i) it helps the students to compare with the grounded conducting sphere image problem in electrostatics, and (ii) offers a greater degree of difficulty since the source is a dipole (vector), rather than an electric charge (scalar). The present work demonstrates an intuitive way of solving the problem. The case in which the source dipole is oriented radially with respect to the sphere is solved with a single dipole image. In the case of the transverse orientation of the source dipole, we model the dipole as a current loop. Then, we find the image of the radial and transverse current elements that satisfy the boundary conditions. Then, we show that this method can be used to deduce the form of the image dipoles when the dipole is oriented in the transverse direction. This method is very much intuitive and accessible for undergraduate-level students.

Dual subwavelength-grating topology for building polarization beam splitters

Abstract A polarization beam splitter (PBS) is key for building polarization-diversity systems in optical communication networks. Here, we propose a compact and easy-to-fabricate PBS based on a dual subwavelength-grating (DSWG) structure positioned between two Si waveguides on a silicon-on-insulator platform. The coupling strengths of the transverse-electric (TE) and transverse-magnetic (TM) modes were selectively modified, with TE mode suppression and TM mode enhancement. By optimizing the duty cycles along transverse and longitudinal directions of the DSWG structure, the device length is reduced by approximately 40%, and the polarization extinction ratio (PER) of the TM mode is improved by ~5 dB at a wavelength of 1.55 μm, compared to a single subwavelength grating (SSWG) structure. Numerical simulations revealed high polarization extinction ratios (PERs) and low insertion losses (ILs) of 26.7 dB (0.1 dB) for TE mode and 23.2 dB (0.28 dB) for TM mode, with a compact footprint of 1.34 × 2.86 μm². Across a bandwidth of ~90 nm within the C-band (1.53–1.56 μm), the proposed PBS achieves a TM mode PER of ~20 dB, a TE mode PER greater than 25 dB, and ILs below 0.25 dB for both modes. This approach, utilizing biaxial anisotropic metamaterials, offers a flexible method for integrating PBSs into photonic integrated circuits using standard semiconductor fabrication processes.

Experimental Assessment of the Turbulent Flow Field Due to Emergent Vegetation at a Sharply Curved Open Channel

Emergent vegetation in river corridors influences both the flow structure and subsequent fluvial processes. This investigation aimed to analyze the impact of the bending and vegetation components in a sharply curved open channel on the flow field. Experiments were undertaken in a meandering flume (0.9 m wide, wavelength of 3.2 m, and a sinuosity of 1.05) with a 90-degree bend at the end of it, with and without vegetation, to achieve this goal. The individual vegetation elements arranged across the 90-degree bend of the flow channel were physically modelled using rigid plastic stems (of 5 mm and 10 mm diameters). Analysis of the findings from the flow velocimetry, taken at five cross-sections oriented at angles of 0°, 30°, 45°, 60°, and 90°, along the 90-degree bend indicates that as the plant density increases, the effect of centrifugal force from the channel’s bend on the cross-sectional flow patterns decreases. At the same time, the restricting influence of vegetation on lateral momentum transfer becomes more pronounced. Specifically, for increasing vegetation density: (a) higher transverse and vertical velocities are observed (increased by 4.35% and 9.68% for 5 mm and 10 mm reed vegetation, respectively, compared to the non-vegetated case); (b) greater turbulence intensity is seen in the transverse flow direction, along with increased turbulent kinetic energy (TKE); and (c) reduced near-bed Reynolds stresses are found. The average transverse flow velocity for the non-vegetated case is 18.19% of the longitudinal flow velocity and the average vertical velocity for the non-vegetated case and 5 mm and 10 mm reed vegetation is 3.24%, 3.6%, and 5.44% of the longitudinal flow velocity, respectively.

Численное моделирование смешанной конвекции в жидком металле при подъемном течении по круглой обогреваемой трубе в условиях поперечного магнитного поля

Hydrodynamics and heat transfer in mixed convection of liquid metal (Pr=0.025) in a vertical pipe with an upward flow in a transverse magnetic field are considered. The study was carried out using a direct numerical simulation method. Simulations were performed at Reynolds numbers up to 12,000, Richardson numbers from 0 to 2.4 and Hartmann numbers up to 550 for two limiting cases of pipe wall conductivity. The simulation results for an isolated pipe were compared with the measurement data from the mercury experiments. The effect of the transverse magnetic field is manifested in the suppression of turbulent transfer and flow laminarization with the formation of strong inhomogeneity of the longitudinal velocity profile by angle and gradients of the streamwise velocity in the transverse direction. Depending on the pipe wall conductivity and the ratios of such parameters as Richardson and Hartmann numbers, the resulting flows with different topology of the longitudinal velocity profile determine the wall temperature distribution in the wall and the values of the heat transfer coefficients. It is shown that in a magnetic field in the case of isolated walls with an increase in the Richardson number the flow has a tendency to instability, which develops in the jets formed in the region of Roberts layers. The periodic process of development and breakage of jets leads to the emergence and development of vortex structures that persist in the magnetic field and cause fluctuations in the velocity and temperature components in the flow. The dependence of the friction factor and heat transfer (Nusselt number) on the Richardson number is obtained.

ρ meson transverse momentum-dependent parton distributions

In this paper, the light-front wave functions (LFWFs) of the ρ meson are evaluated in the framework of the Nambu–Jona-Lasinio model using the proper time regularization scheme. The transverse momentum-dependent parton distributions (TMDs) of the ρ meson are derived from the overlap representations of the LFWFs. We investigate the k⊥-weighted moments and the x-dependent average transverse momentum ⟨k⊥n(x)⟩α of ρ meson TMDs. The ⟨k⊥n(x)⟩α shows the typical transverse momenta of quark TMDs in our model. Our findings indicate that the average transverse momenta of ⟨k⊥(x)⟩α fall within the range of [0.3, 0.45] GeV, while ⟨k⊥2(x)⟩α are in the region of [0.15, 0.30] GeV2. Our TMDs and parton distribution functions (PDFs) exhibit excellent adherence to positive constraints. The investigation of spin densities within the ρ meson in transverse momentum space reveals axially symmetric distributions for quarks and targets polarized in either the longitudinal or transverse direction. Conversely, unpolarized symmetric distributions occur when the quark is longitudinally polarized and the target is transversely polarized, while exhibiting dipolar distortions in the opposite scenario. A comparison between TMDs from LFWFs and those from a covariant approach demonstrates that TMDs from LFWFs more effectively satisfy positive constraints than their counterparts from the covariant approach. Furthermore, the x-moments of ρ meson PDFs indicate that ⟨x⟩gL is larger using LFWFs than with the covariant approach. Additionally, analysis of quark spin densities within the ρ meson reveals that ρ↑↓kx,ky=f-gL-13fLL yields a negative result using the covariant approach, whereas ρ↑↓kx,ky derived from LFWFs produces a positive outcome.

Orientation effect and locational variation in elastic-plastic compressive properties of bovine cortical bone.

Bone is a highly heterogeneous and anisotropic material with a hierarchical structure. The effect of diaphysis locations and directions of loading on elastic-plastic compressive properties of bovine femoral cortical bone was examined in this study. The impact of location and loading directions on elastic-plastic compressive properties of cortical bone was found to be statistically insignificant in this study. The variances of most of the compressive properties were also observed to be location and directionality independent except for the locational differences in modulus of resilience (distal to central for longitudinal loading) and plastic work (central to distal for transverse loading) as well as differences in variances of the modulus of resilience and elastic modulus values for two directions of loading. The micro-mechanisms of cortical bone failure for longitudinal and transverse directions of loading were considered to be responsible for the difference in variances in the later properties values as well as for the maximum and minimum coefficient of variation (CV) obtained for compressive properties in two directions of loading. The representative cubical volume at the tested hierarchical level contained all unique microstructural features of the plexiform bone and therefore produced the homogeneous and isotropic elastic-plastic compressive properties of cortical bone. It is expected that the outcome of this study may be helpful in the area of bone tissue engineering and finite element simulation of cortical bone.

Drop‐Weight Impact Analysis of Unidirectional Sisal Fiber –Reinforced Epoxy Resin Composite Material for Automotive Application Based on ASTM D‐7136 Standard

The main goal of this study is to investigate the drop‐weight impact analysis of sisal fiber–reinforced epoxy resin composite materials for automotive applications using Abaqus/CAE software based on the ASTM D‐7136 standard. For this simulation, a [0/0]s unidirectional sisal/epoxy composite laminate with an overall thickness of 2.16 mm was used, and 0.5, 1, 2, and 3 kg of a rigid hemispherical impactor mass with 1, 2, and 3 m/s of velocities were used to deal with their effects on the composite laminates. The result revealed that the initial damage mechanism in the impact event is the interplay matrix crack. After that, matrix and fiber debonding, fiber breakage, and penetration occurred depending on the mass and velocity of the impactor. In addition, when the impactor mass and velocity increase, the composite plate’s reaction forces and energy absorption increase up to 1 kg of the impactor at 3 m/s. However, for 2 and 3 kg of the impactor mass, the energy absorption capacity of the material is decreased due to the high damage and perforation of the composite laminate. In general, it is found that the unidirectional sisal fiber–reinforced epoxy resin composite material has a moderate energy absorption capacity in the transverse direction and has the potential to be used for different automotive interior body applications.

Moisture effects on the transverse compressive behaviour of single flax fibres

Studying the effects of moisture on the mechanical behaviour of single flax fibres, particularly in the transverse direction, is of key importance for the reliable use of biobased composites exposed to varying humidity levels. In this study, the apparent transverse Young’s modulus evolution of single flax fibres is recorded through repeated compressive load/unload cycles conducted at three Relative Humidity (RH) levels— 40%, 60%, and 80%. No significant changes in the apparent Young’s modulus, determined from the unloading, were observed during transverse compression cycling or under increasing humidity conditions. The absence of apparent softening with the rise in RH is attributed to the expression of two antagonistic mechanisms: wall softening due to plasticisation and structural stiffening linked to fibre compaction. Intriguingly, a noteworthy transverse stiffening is recorded at 40% RH following the humidification and drying of the fibre. This outcome is ascribed to a hornification phenomenon.

The ITS3 detector and physics reach of the LS3 ALICE Upgrade

During Large Hadron Collider (LHC) Long Shutdown 3 (LS3) (2026-30), the ALICE experiment is replacing its inner-most three tracking layers by a new detector, Inner Tracking System 3. It will be based on newly developed wafer-scale monolithic active pixel sensors, which are bent into truly cylindrical layers and held in place by light mechanics made from carbon foam. Unprecedented low values of material budget (per layer) and closeness to interaction point (19 mm) lead to a factor two improvement in pointing resolutions from very low pT (O(100MeV/c)), achieving, for example, 20 µm and 15 µm in the transversal and longitudinal directions, respectively, for 1 GeV/c primary charged pions. After a successful R&D phase 2019-2023, which demonstrated the feasibility of this innovational detector, the final sensor and mechanics are being developed. This contribution briefly reviews the conceptual design and the main R&D achievements, as well as the current activities and road to completion and installation. It concludes with a projection of the improved physics performance, in particular for heavy-flavour hadrons, as well as for thermal dielectrons, that will come into reach with this new detector installed.