Expansion Of Shell Research Articles

Critical diameter for a single-tank molten salt storage – Parametric study on structural tank design

Molten salt thermal energy storage (TES) is a cost-effective option for grid-connected storage in both concentrating solar power (CSP) plants and retrofitted thermal power plants in a multimegawatt scale. Current systems use two tanks (hot and cold), but future systems may use a single tank with a transient temperature profile (hot in the top and cold in the bottom) to reduce costs and space. However, the structural and mechanical design of large-scale molten salt single-tank storages at 560 °C has not been fully explored, and the impact of increasing the operating temperature to 620 °C is still uncertain. The challenge presented by a single tank is the existence of a temperature profile that results in a varying thermal expansion of the tank shell along its height. In the case of larger tanks, this discrepancy can reach a magnitude of centimeters, which in turn gives rise to bending moments. To the best of our knowledge, this study addresses the issue of bending stresses in large-sized high-temperature tanks with thermal stratification for the first time. The modelling approach is applied to single-tank CSP TES systems as a case study to evaluate the constraints imposed by tank size and wall thickness.With the help of experimentally validated numerical methods, it is revealed that a low thermocline thickness can be a limiting factor for large tank diameters. It is shown that the temperature has a major influence on maximum possible tank size: if the operating temperature is raised from 560 °C to 620 °C, the permitted tank diameter is significantly reduced when using the same tank wall material. A possible approach is to use a more heat resistant steel for 620 °C. Results of the parametric study show that designing a single tank below a critical diameter only requires a moderate increase of the wall thickness compared to the two-tank system with constant temperature profiles. Based on this parametric study a formula for the critical tank diameter is developed and presented in this work. The paper concludes with recommendations on how increased wall stresses can be addressed by an appropriate design.

Temperature-induced structure evolution in monocrystalline and polycrystalline cobalt via molecular dynamics simulations

The structure transition of metallic melt strongly depends on temperature and significantly influences the comprehensive properties. However, observing the structure change in experiments is still challenging. Here, molecular dynamics is used to study the melting process and microstructural evolution in single crystal and polycrystal cobalt (Co). The results indicate that the melting process of single crystal structure starts from 1870 K and lasts for a very short period, while the polycrystal melts from about 1760 to 1870 K. In polycrystal Co, the melting initially occurs in grain boundaries, and the melting temperature shows a positive correlation with grain size. An interesting solidification phenomenon occurs on the surface of big grains in the beginning of melting process. The coordination number increasing from 12 to about 13.4 near melting point proves the local expansion of the first coordination shell, indicating the structural evolution from long-range order to short-range order in the continuous heating process. The common neighbor sub-cluster index and Voronoi polyhedron demonstrate the short-range icosahedron structures, while these polyhedrons become polydisperse and isolated in Co liquid. The findings ignite the investigation of the liquid structure origin of crystal materials and extend the understanding of the atomic structure evolution in melting.

Rapid Release of Silicon by Ultrafast Joule Heating Generates Mechanically Stable Shell-Shell Si/C Anodes with Dominant Inward Deformation.

As a promising anode material, silicon-carbon composites encounter great challenges related to internal stress release and contact between the composites during lithiation. These issues lead to material degradation and concomitantly rapid capacity decline. Here, we report a type of shell-shell silicon-carbon (SS-Si/C) composite, which consists of a carbon shell tightly coated with a silicon shell. The mechanical analysis unveils that the dominant inward expansion of the Si shell is achieved through the synergistic effect of the outer carbon shell and the inner hollow structure. Benefiting from the well-tailored shell-shell structure, the SS-Si/C anode exhibits exceptional performance, boasting a high specific capacity (1690.3 mA h g-1 after 550 cycles at 0.5 A g-1), a high areal capacity (2.05 mA h cm-2 after more than 400 cycles at 0.5 mA cm-2), and an extended cycling life (1055.6 mA h g-1 after 1000 cycles at 8 A g-1), far exceeding commercially available Si/C anodes. Using the well-designed SS-Si/C anode, full cells assembled with LiCoO2 (LCO) or LiFePO4 (LFP) cathodes achieve favorable rate capability and cyclic stability. Notably, at a high rate of 6 C (1 C = 170 and 270 mA g-1 for LFP and LCO, respectively), these full cells deliver high specific capacities of 79.5 mA h g-1 and 64.9 mA h g-1 when using LCO and LFP, respectively, demonstrating the potential of SS-Si/C anodes for practical applications. The straightforward and safe synthesis method in this work enables the rational design of hollow structures with distinct properties.

A Novel Model for the MeV Emission Line in GRB 221009A

Gamma-ray bursts (GRBs) have long been considered potential sources of ultrahigh-energy cosmic rays (UHECRs; with energy ≳1018 eV). In this work, we propose a novel model generating MeV emission lines in GRBs, which can constrain the properties of heavy nuclei that potentially exist in GRB jets. Specifically, we find that relativistic hydrogen-like high-atomic-number ions originating from the β decay of unstable nuclei and/or the recombination entrained in the GRB jet can generate narrow MeV emission lines through the de-excitation of excited electrons. This model can successfully explain the MeV emission line observed in the most luminous GRB ever recorded, GRB 221009A, with suitable parameters including a Lorentz factor γ ∼ 820–1700 and a total mass of heavy nuclei M tot ∼ 1023–1026 g. Especially, the emission line broadening can be reasonably attributed to both the expansion of the jet shell and the thermal motion of nuclei, naturally resulting in a narrow width (σ line/E line ≲ 0.2) consistent with the observation. Furthermore, we predict that different GRBs can exhibit lines in different bands with various evolving behaviors, which might be confirmed with further observations. Finally, our model provides indirect evidence that GRBs may be one of the sources of UHECRs.

Investigation of swelling degree of polypropylene beads with monomers and blowing agents

AbstractThe swelling step of polymer particles or beads with blowing agents and monomers is one of the factors that directly affect the performance properties of expandable core–shell particles, including morphology, composition, and expansion degree. In this regard, the present work investigated the effect of swelling agents on polypropylene (PP) beads. Swelling agents were used to perform swelling tests in both bulk and suspension media at different temperatures and stirring rates. Additionally, a mass transfer model was implemented to predict the swelling degree at the analyzed experimental conditions. The obtained results indicated the important effect of temperature on swelling in both bulk and suspension tests. Among the investigated swelling agents, higher rates of PP beads swelling were observed when styrene was employed (~80 wt%), when compared to methyl methacrylate (~20 wt%), vinyl acetate (~9 wt%), and acrylonitrile (~6 wt%). Moreover, it seems that the stirring rate does not exert a considerable influence on the swelling rates, indicating that swelling is controlled by thermodynamic constraints and particle properties. Finally, experimental results showed that the final saturation concentration of the swelling agent can be reached before 1 hour of swelling, indicating that the swelling kinetics can be much faster than the polymerization kinetics.Highlights The effects of non‐conventional swelling agents on PP were investigated. The swelling presented a fast dynamic behavior. The swelling dynamics was controlled by the solubility of the swelling agent. The highest swelling degree was obtained with styrene.

Experimental study on self-burrowing dual anchor soft probe

This study focuses on the development and testing of a bio-inspired self-burrowing dual anchor soft probe for potential geotechnical applications. Dual anchor refers to the form of movement in soils in which some bivalve molluscs adopted by alternately generating anchoring effects in the soil through shell expansion and fluid-filled feet. By mimicking this mechanism, this study used pneumatic artificial muscles as soft actuators and developed an autonomous burrowing probe. The structure and the performance of the actuators and the probe were investigated and optimized. The burrowing-out process of the dual anchor probe was not a simple upward movement. Instead, it rose in the inflation phase and slipped downward in the deflation phase. The difference between the two was a stride in one single step. In the sands with relative densities of 30%, 50%, and 80%, the total slips accounted for 18.8%, 19.6%, and 26.9% of the total upward movements, respectively. Thus, the entire movement process showed a reciprocating upward trend. The burrowing process could be divided into a restricted stage and a free stage according to whether shear failure occurs in the overlying soil layer. When the soil density was high, the initial stage of burrowing was in a restricted stage. The amount of rise and slip were at a low level and increased slowly as the number of cycles increased. When the burrowing process was in the free stage, the increase was basically stable at a high value and accompanied by small slips.

Real-time structural dynamics of the ultrafast solvation process around photo-excited aqueous halides.

This work investigates and describes the structural dynamics taking place following charge-transfer-to-solvent photo-abstraction of electrons from I- and Br- ions in aqueous solution following single- and 2-photon excitation at 202 nm and 400 nm, respectively. A Time-Resolved X-ray Solution Scattering (TR-XSS) approach with direct sensitivity to the structure of the surrounding solvent as the water molecules adopt a new equilibrium configuration following the electron-abstraction process is utilized to investigate the structural dynamics of solvent shell expansion and restructuring in real-time. The structural sensitivity of the scattering data enables a quantitative evaluation of competing models for the interaction between the nascent neutral species and surrounding water molecules. Taking the I0-O distance as the reaction coordinate, we find that the structural reorganization is delayed by 0.1 ps with respect to the photoexcitation and completes on a time scale of 0.5-1 ps. On longer time scales we determine from the evolution of the TR-XSS difference signal that I0: e- recombination takes place on two distinct time scales of ∼20 ps and 100 s of picoseconds. These dynamics are well captured by a simple model of diffusive evolution of the initial photo-abstracted electron population where the charge-transfer-to-solvent process gives rise to a broad distribution of electron ejection distances, a significant fraction of which are in the close vicinity of the nascent halogen atoms and recombine on short time scales.

TCP J18224935-2408280: a symbiotic star identified during outburst

ABSTRACT TCP J18224935-2408280 was reported to be in outburst on 2021 May 19. Follow-up spectroscopic observations confirmed that the system was a symbiotic star. We present optical spectra obtained from the Himalayan Chandra Telescope during 2021–22. The early spectra were dominated by Balmer lines, He i lines and high ionization lines such as He ii. In the later observations, Raman scattered O vi was also identified. Outburst in the system started as a disc instability, and later the signature of enhanced shell burning and expansion of photospheric radius of the white dwarf was identified. Hence we suggest this outburst is of combination nova type. The post-outburst temperature of the hot component remains above 1.5 × 105 K indicating a stable shell burning in the system for a prolonged time after the outburst. Based on our analysis of archival multiband photometric data, we find that the system contains a cool giant of M1-2 III spectral type with a temperature of ∼3600 K and a radius of ∼69 R⊙. The pre- and post-outburst light curve shows a periodicity of 631.25 ± 2.93 d; we consider this as the orbital period.

An SiO Toroid and Wide-angle Outflow Associated with the Massive Protostar W75N(B)-VLA2

We have carried out Atacama Large Millimeter/submillimeter Array observations of the massive star-forming region W75N(B), which contains the massive protostars VLA1, VLA2, and VLA3. Particularly, VLA2 is an enigmatic protostar associated with a wind-driven H2O maser shell, which has evolved from an almost isotropic outflow to a collimated one in just 20 yr. The shell expansion seemed to be halted by an obstacle located to the northeast of VLA2. Here we present our findings from observing the 1.3 mm continuum and H2CO and SiO emission lines. Within a region of ∼30″ (∼39,000 au) diameter, we have detected 40 compact millimeter continuum sources, three of them coinciding with VLA1, VLA2, and VLA3. While the H2CO emission is mainly distributed in a fragmented structure around the three massive protostars, but without any of the main H2CO clumps spatially coinciding with them, the SiO is highly concentrated on VLA2, indicating the presence of very strong shocks generated near this protostar. The SiO emission is clearly resolved into an elongated structure (∼0.″6 × 0.″3; ∼780 au×390 au) perpendicular to the major axis of the wind-driven maser shell. The structure and kinematics of the SiO emission are consistent with a toroid and a wide-angle outflow surrounding a central mass of ∼10 M ⊙, thus supporting previous theoretical predictions regarding the evolution of the outflow. Additionally, we have identified the expected location and estimated the gas density of the obstacle that is hindering the expansion of the maser shell.

Synthesis of hollow bimetallic nanoparticles from Ultrafast Laser Irradiation: An atomistic simulation study

Femtosecond laser irradiation in Au@Ag, Ag@Au core@shell, and Au–Ag Janus-like nanoparticles are investigated using molecular dynamics simulations. Our results show that the morphology of Au@Ag core–shell and Au–Ag Janus-like nanoparticles tend to form hollow-like nanostructures due to the ultrafast energy transfer and the subsequent cooling process. In contrast, our results also shows that Ag@Au nanoparticles do not form a hollow structure due to the high diffusion of Ag atoms and the limited expansion of the Au shell. Besides, successive laser impacts on the Au–Ag Janus-like nanoparticle produce a structure that alternates from hollow to a solid nanoparticle and, at the same time, promotes atomic diffusion, favoring the alloying process of the Ag and Au atoms. In addition, the evolution of the crystalline structure is studied, observing a saturation of the planar defects due to the impossibility of forming a new crystalline phase. The energy variation between the initial and final step, it is not influenced by the presence of the hollow, however it is dominated by the increase of planar defects.

3D-Spatiotemporal forecasting the expansion of supernova shells using deep learning towards high-resolution galaxy simulations

ABSTRACT Supernova (SN) plays an important role in galaxy formation and evolution. In high-resolution galaxy simulations using massively parallel computing, short integration time-steps for SNe are serious bottlenecks. This is an urgent issue that needs to be resolved for future higher-resolution galaxy simulations. One possible solution would be to use the Hamiltonian splitting method, in which regions requiring short time-steps are integrated separately from the entire system. To apply this method to the particles affected by SNe in a smoothed particle hydrodynamics simulation, we need to detect the shape of the shell on and within which such SN-affected particles reside during the subsequent global step in advance. In this paper, we develop a deep learning model, 3D-Memory In Memory (3D-MIM), to predict a shell expansion after a SN explosion. Trained on turbulent cloud simulations with particle mass mgas = 1 M⊙, the model accurately reproduces the anisotropic shell shape, where densities decrease by over 10 per cent by the explosion. We also demonstrate that the model properly predicts the shell radius in the uniform medium beyond the training data set of inhomogeneous turbulent clouds. We conclude that our model enables the forecast of the shell and its interior where SN-affected particles will be present.

Radio Observations of Six Young Type Ia Supernovae

Type Ia supernovae (SNe Ia) are important cosmological tools, probes of binary star evolution, and contributors to cosmic metal enrichment; yet, a definitive understanding of the binary star systems that produce them remains elusive. Of particular interest is the identity of the mass-donor companion to the exploding carbon–oxygen white dwarf (CO WD). In this work, we present early-time (first observation within 10 days post-explosion) radio observations of six nearby (within 40 Mpc) SNe Ia taken by the Jansky Very Large Array, which are used to constrain the presence of synchrotron emission from the interaction between ejecta and circumstellar material (CSM). The two motivations for these early-time observations are: (1) to constrain the presence of low-density winds and (2) to provide an additional avenue of investigation for those SNe Ia observed to have early-time optical/UV excesses that may be due to CSM interaction. We detect no radio emission from any of our targets. Toward our first aim, these non-detections further increase the sample of SNe Ia that rule out winds from symbiotic binaries and strongly accreting white dwarfs. and discuss the dependence on underlying model assumptions and how our observations represent a large increase in the sample of SNe Ia with low-density wind constraints. For the second aim, we present a radiation hydrodynamics simulation to explore radio emission from an SN Ia interacting with a compact shell of CSM, and find that relativistic electrons cannot survive to produce radio emission despite the rapid expansion of the shocked shell after shock breakout. The effects of model assumptions are discussed for both the wind and compact shell conclusions.

Probing Sodium Storage Mechanism in Hollow Carbon Nanospheres Using Liquid Phase Transmission Electron Microscopy.

Carbonaceous materials are promising sodium-ion battery anodes. Improving their performance requires a detailed understanding of the ion transport in these materials, some important aspects of which are still under debate. In this work, nitrogen-doped porous hollow carbon spheres (N-PHCSs) are employed as a model system for operando analysis of sodium storage behavior in a commercial liquid electrolyte at the nanoscale. By combining the ex situ characterization at different states of charge with operando transmission electron microscopy experiments, it is found that a solvated ionic layer forms on the surface of N-PHCSs at the beginning of sodiation, followed by the irreversible shell expansion due to the solid-electrolyte interphase (SEI) formation and subsequent storage of Na(0) within the porous carbon shell. This shows that binding between Na(0) and C creates a Schottky junction making Na deposition inside the spheres more energetically favorable at low current densities. During sodiation, the SEI fills the gap between N-PHCSs, binding spheres together and facilitating the sodium ions' transport toward the current collector and subsequent plating underneath the electrode. The N-PHCSs layer acts as a protective layer between the electrolyte and the current collector, suppressing the possible growth of dendrites at the anode.

Pre-control of shell expansion fracture process by high energy beam

Aiming at the dynamic deformation and fracture response of high-energy precontrolled shell under high strain rate,the expansion and fracture process of 40CrMnSiB steel precontrolled shell was studied by numerical modeling and experiment.The results show that:In detonation loading condition,the high energy beam precontrol shell expansion fracture process can be divided into three stages of free expansion,precontrol fracture and matrix fracture.Firstly, the brittle fracture occurs in the fusion region, and the crack starts at the bottom of the cavity region and propagates along the fusion region to the outer wall of the shell. After the brittle fracture is completed, the adiabatic shear fracture occurs in the matrix, and the normal line between the fracture surface and the inner wall of the fragment is 45 °.The recovered fragment shape is in the shape of precontrolled quadpyramid,and the fragment quality is concentrated in the precontrol area. the fragment dispersion has a good distribution law,which better verifies the pre-control effect of high-energy beam pre-control technology on the fragment shape and the direction of dispersion,and provides technical reference for further optimization of high-energy beam pre-control warhead structure.

Thermal-/pH-triggered hollow mesoporous carbon nanocarrier for NIR-responsive drug release

Intelligent drug-delivery systems are considered one of the most important techniques for improving cancer treatment using existing over-the-counter medicines. However, metallic materials are always accompanied by metabolism problems, whereas chemotherapy produces several side effects in humans. Carbon-based materials exhibit exceptional features such as bio-affinity and bio-degradability. Herein, hollow mesoporous carbon nanoparticles (HMCs) are reported as effective nanocarriers of anti-cancer small drug molecules. Near IR (NIR) sources, which can penetrate most organs, induce thermal effects via non-invasive pathways. NIR radiation not only provides thermal therapy but also is compatible with temperature-sensitive coated responsive polymer shells. The template method was used to synthesize HMCs with size 200 ± 50 nm, under various conditions, to obtain suitably sized and hollow structures for liver-cancer treatment. Additional pH/thermal-bi-responsive poly(N-isopropylacrylamide) (PNIPAM) shells were further coated onto the HMCs to produce multiple shells that could trigger swelling motions in PNIPAM@HMCs, as confirmed via small-angle X-ray scattering (SAXS). NIR results demonstrated an extreme increase to the ∆T of 8.7 and 14.2 °C for HMC and PNIPAM@HMCs, respectively. The SAXS spectra analyzed using SasView simulations demonstrated the multi-shell structures of synthesized HMCs and the release mechanism of PNIPAM@HMCs. Based on the model simulation of SAXS, the different rates of polymer swelling indicated the core shrinkage (229.7 to 134.2 Å) and shell expansion (324.3 to 514.3 Å) at 37 °C and 42 °C, respectively. In addition, the first-order, Higuchi, Korsmeyer–Peppas, and Weibull mathematical models were used to verify the drug-release kinetics, and the model with the highest R2 value was considered most suitable for further application. This paper presents the first SAXS study on PNIPAM@HMCs release kinetics and related mechanisms. This phenomenon indicates NIR-induced PNIPAM@HMCs as an effective strategy for cancer treatment via doxorubicin release.

Effects of feedback on galaxies in the VELA simulations: elongation, clumps, and compaction

ABSTRACT The evolution of star-forming galaxies at high redshifts is very sensitive to the strength and nature of stellar feedback. Using two sets of cosmological, zoom-in simulations from the VELA suite, we compare the effects of two different models of feedback: with and without kinetic feedback from the expansion of supernovae shells and stellar winds. At a fixed halo mass and redshift, the stellar mass is reduced by a factor of ∼1–3 in the models with stronger feedback, so the stellar mass–halo mass relation is in better agreement with abundance matching results. On the other hand, the three-dimensional shape of low-mass galaxies is elongated along a major axis in both models. At a fixed stellar mass, M* < 1010 M⊙, galaxies are more elongated in the strong-feedback case. More massive, star-forming discs with high surface densities form giant clumps. However, the population of round, compact, old (agec > 300 Myr), quenched, stellar (or gas-poor) clumps is absent in the model with strong feedback. On the other hand, giant star-forming clumps with intermediate ages (agec = 100–300 Myr) can survive for several disc dynamical times, independently of feedback strength. The evolution through compaction followed by quenching in the plane of central surface density and specific star formation rate is similar under the two feedback models.

Influence of combination of coaxial cylindrical explosives on fragmentation and shock waves of a shelled composite charge

AbstractThis paper investigates fragmentation and shock waves generated by a novel coaxial cylindrical composite charge composed of an inner explosive, an intermediate inert material and an outer explosive widely used in tunable ammunition. Charges containing two types of explosive combinations were designed, and explosion experiments were conducted in two initiation modes: detonating only an inner explosive and detonating inner and outer explosives simultaneously. Results suggest the composite charge with higher inner‐detonation velocity and lower outer‐detonation velocity achieves more differentiated power output under different initiations. The differences in the average fragment mass and peak overpressure are as high as 34.5 % and 39.9 %, respectively, which are larger than 4.4 % and 8.4 % under the contrary explosive combination. On the basis of this observation, corresponding 2‐D and 3‐D models were simulated using AUTODYN code to investigate the evolution of the detonation waveform and detonation energy release. The numerically simulated initial shell expansion and later shock wave propagation of the composite charge agreed well with the experimental data. The errors in expansion radius and shock wave parameters (peak overpressure and specific impulse) are less than 6.6 % and 16.9 %, respectively, between the simulations and experiments. It was found that the particle velocity profile in the charge with lower outer‐detonation velocity lagged behind that of the charge with higher inner‐detonation velocity under inner initiation, while a wave front collision zone close to the outer charge appeared in the non‐detonation layer under simultaneous initiation.

Rapid Expansion of the Young Type Ia Supernova Remnant 0519–69.0: More Evidence for a Circumstellar Shell

The nature of Type Ia supernovae remains controversial. The youngest remnants of Ia supernovae hold clues to the explosion and to the immediate surroundings. We present a third epoch of Chandra observations of the ∼600 yr old Type Ia remnant 0519–69.0 in the Large Magellanic Cloud, extending the time baseline to 21 yr from the initial 2000 observations. We find rapid expansion of X-ray emitting material, with an average velocity of 4760 km s−1. At the distance of the LMC, this corresponds to an undecelerated age of 750 yr, with the true age somewhat lower. We also find that the bright ring of emission has expanded by 1.3%, corresponding to a velocity of 1900 km s−1 and an undecelerated age of 1600 yr. The high velocity of the peripheral X-rays, contrasted with the modest expansion of the main X-ray shell, provides further evidence for a massive shell of circumstellar material.

Flipper-Style Locomotion Through Strong Expanding Modular Robots

Volume-changing robotic units present an exciting pathway for modular robotics. However, current attempts have been relatively limited, requiring tethers, complex fabrication or slow cycle times. In this letter, we present AuxBots: an auxetic-based approach to create high force, fast cycle time self-contained modules. By driving the auxetic shell's expansion with a motor and leadscrew, these robots are capable of expanding their volume by 274% in 0.8 seconds with a maximum strength to weight ratio of 76x. These force and expansion properties enable us to use these modules in conjunction with flexible wire constraints to get shape changing behavior and independent locomotion. We demonstrate the power of this modular system by using a limited number of AuxBots to mimic the flipper-style locomotion of mudskippers and sea turtles. These structures are entirely untethered and can still move forward even as some AuxBots stall and enter a fault state, achieving the key modular robotics goals of versatility and robustness.

Structures of a large prolate virus capsid in unexpanded and expanded states generate insights into the icosahedral virus assembly

Many icosahedral viruses assemble proteinaceous precursors called proheads or procapsids. Proheads are metastable structures that undergo a profound structural transition known as expansion that transforms an immature unexpanded head into a mature genome-packaging head. Bacteriophage T4 is a model virus, well studied genetically and biochemically, but its structure determination has been challenging because of its large size and unusually prolate-shaped, ∼1,200-Å-long and ∼860-Å-wide capsid. Here, we report the cryogenic electron microscopy (cryo-EM) structures of T4 capsid in both of its major conformational states: unexpanded at a resolution of 5.1 Å and expanded at a resolution of 3.4 Å. These are among the largest structures deposited in Protein Data Bank to date and provide insights into virus assembly, head length determination, and shell expansion. First, the structures illustrate major domain movements and ∼70% additional gain in inner capsid volume, an essential transformation to contain the entire viral genome. Second, intricate intracapsomer interactions involving a unique insertion domain dramatically change, allowing the capsid subunits to rotate and twist while the capsomers remain fastened at quasi-threefold axes. Third, high-affinity binding sites emerge for a capsid decoration protein that clamps adjacent capsomers, imparting extraordinary structural stability. Fourth, subtle conformational changes at capsomers' periphery modulate intercapsomer angles between capsomer planes that control capsid length. Finally, conformational changes were observed at the symmetry-mismatched portal vertex, which might be involved in triggering head expansion. These analyses illustrate how small changes in local capsid subunit interactions lead to profound shifts in viral capsid morphology, stability, and volume.