Rotation Of Nucleus Research Articles

Determination of Photon Mass with its Main Physical Parameters Energy, Wavelength and Velocity

The excitation, transition, vibration and rotation of nuclei, atoms and molecules leading to the emission of all photons from gamma rays to radio waves as a result of the physical mechanisms responsible for excited states. The photon energy with its corresponding frequency, wavelength and distance can be determined by the main physical parameters (mass, distance, time) of the mentioned particles (Sanad, 2024). The photon mass as a particle can be determined by its main physical parameters (energy, wavelength, velocity). The determined photon mass is 2.2X10-34 kg and it is the same value of all electromagnetic radiation from gamma rays to radio waves.

Predictions for Sparse Photometry of Jupiter-family Comet Nuclei in the LSST Era

The Legacy Survey of Space and Time (LSST) at Vera C. Rubin Observatory will deliver high-quality, temporally sparse observations of millions of solar system objects on an unprecedented scale. Such data sets will likely enable the precise estimation of small-body properties on a population-wide basis. In this work, we consider the possible applications of photometric data points from LSST to the characterization of Jupiter-family comet (JFC) nuclei. We simulate sparse-in-time lightcurve points with an LSST-like cadence for the orbit of a JFC between 2024 and 2033. Convex lightcurve inversion is used to assess whether the simulation input parameters can be accurately reproduced for a sample of nucleus rotation periods, pole orientations, activity onsets, shapes, and sizes. We find that the rotation period and pole direction can be reliably constrained across all nucleus variants tested, and that the convex shape models, while limited in their ability to describe complex or bilobed nuclei, are effective for correcting sparse photometry for rotational modulation to improve estimates of nucleus phase functions. Based on this analysis, we anticipate that LSST photometry will significantly enhance our present understanding of the spin state and phase function distributions of JFC nuclei.

Fast rotation of nuclei with extreme isospin in the vicinity of neutron and proton drip lines

The analysis of the present understanding of collective rotation in very neutron-rich nuclei is presented. It is shown that collective rotation can lead to the increase of stability of rotational states with increasing spin. The detailed investigation of rotational excitations in very proton-rich nuclei confirms this conclusion and indicates that experimental studies of such features are more feasible in the nuclei near proton drip line. They also show that rotational bands which are proton quasi-bound at zero or low spins can be transformed into proton bound ones at high spin by collective rotation of nuclear systems. This is due to strong Coriolis interaction which acts on high-j or strongly mixed M orbitals and drives the highest in energy occupied single-particle states into negative energy domain. These physical mechanisms lead to a substantial extension of the nuclear landscape beyond the spin zero proton drip line. In addition, a new phenomenon of the formation of giant proton halos in rotating nuclei emerges: it is triggered by the occupation of strongly mixed M intruder orbitals.

Quasi van der Waals Epitaxy of Single Crystalline GaN on Amorphous SiO2/Si(100) for Monolithic Optoelectronic Integration.

The realization of high quality (0001) GaN on Si(100) is paramount importance for the monolithic integration of Si-based integrated circuits and GaN-enabled optoelectronic devices. Nevertheless, thorny issues including large thermal mismatch and distinct crystal symmetries typically bring about uncontrollable polycrystalline GaN formation with considerable surface roughness on standard Si(100). Here a breakthrough of high-quality single-crystalline GaN film on polycrystalline SiO2/Si(100) is presented by quasi van der Waals epitaxy and fabricate the monolithically integrated photonic chips. The in-plane orientation of epilayer is aligned throughout a slip and rotation of high density AlN nuclei due to weak interfacial forces, while the out-of-plane orientation of GaN can be guided by multi-step growth on transfer-free graphene. For the first time, the monolithic integration of light-emitting diode (LED) and photodetector (PD) devices are accomplished on CMOS-compatible SiO2/Si(100). Remarkably, the self-powered PD affords a rapid response below 250µs under adjacent LED radiation, demonstrating the responsivity and detectivity of 2.01×105 A/W and 4.64×1013Jones, respectively. This work breaks a bottleneck of synthesizing large area single-crystal GaN on Si(100), which is anticipated to motivate the disruptive developments in Si-integrated optoelectronic devices.

Rotational technique for emulsification of soft lens nucleus

This study was conducted to develop a non-ultrasound technique for emulsification of a soft lens nucleus. Fifty-seven patients (57 eyes) underwent surgery. In 23 cases, early or immature cataracts were detected, and in 34 cases, lens removal was performed for refractive purposes in high myopia and complex myopic astigmatism. Phacoemulsifier Centurion Vision System (Alcon Laboratories, Inc., USA) was used for the surgery. Aspiration of soft lens nucleus was done using a rotational technique. The following aspects were evaluated in the course of the surgery: the volume of the required irrigation solution, and the frequency needing to involve ultrasound for complete emulsification of the lens nucleus. Intraoperative and postoperative complications were also assessed. The surgery was uneventful in all cases. There were no violations of the integrity of capsulorhexis edge. The need for short pulses of minimal power ultrasound during the removal of the soft lens using this technique arose only in 11 (19.3%) cases. The effective ultrasound time was less than 1 second. The required volume of irrigation solution was 33.0 (24.0; 43.0) ml, which does not differ significantly from that in ultrasonic phacoemulsification. The use of modern phacoemulsifiers providing a high vacuum level allows successful removal of a soft lens without using ultrasound, which prevents its negative impact on the ocular tissues. The use of adequate surgical techniques, including the optimal direction of rotation of the lens nucleus in the rotational technique, improves the efficiency of soft lens nucleus removal.

Trident technique of safe nuclear emulsification in posterior polar cataracts.

The common complications associated with a posterior polar cataract (PPC) with deficient or weak posterior capsules (PCs) are posterior capsular rupture (PCR), vitreous loss, and luxation of lens material into the vitreous. Often the commonly used technique of hydrodelineation in such cataracts can lead to accidental hydrodissection, and even the slightest nucleus rotation during phacoemulsification can cause the PC to give way. We describe a modified relatively safe technique (Trident technique) for managing the nucleus in PPCs which does not involve any hydroprocedure or nucleus rotation.

Microscopic shell-model description of irrotational-flow dynamics in 102Pd

The structure of the low-lying collective excitations in Pd is examined within the recently proposed microscopic shell-model version of the Bohr-Mottelson (BM) collective model. A good description of the excitation energies of the lowest ground, γ, and β bands, as well as the staggering function between the collective states of the γ band and some other energy-dependent quantities, is obtained. The low-energy intraband and interband quadrupole dynamics is reasonably well described within the present proton-neutron sympletic based shell-model approach without the use of an effective charge and compared with the predictions of nuclear structure models. The obtained results of the present study shed light on the question of the existence of irrotational-flow type quadrupole dynamics, which lies on the ground of the original BM model of quantized vibrations and surface-wave rotations in atomic nuclei.

Shell-model-like approach based on covariant density functional theory in 3D lattice space: Evolution of octupole shape in rotating 224Th

The evolution of the octupole shape with rotation in pear-shaped nuclei is a topic of broad interest. Based on the cranking covariant density functional theory in 3D lattice space, a shell-model-like approach is implemented to take into account the pairing correlations, and applied for the interleaved positive- and negative-parity bands in [Formula: see text]Th. The experimental [Formula: see text] relations are well reproduced. It is found that the octupole deformation of yrast states in [Formula: see text]Th rises slightly and then declines with increasing spin. After the band crossing, the octupole deformation suddenly disappears, i.e., a sharp transition from an octupole shape to a nearly spherical shape takes place at high spins. This is explained by the evolution of the coupling strength between the proton [Formula: see text] and [Formula: see text] orbitals with spin.

Scalable pattern formation of skeletal myotubes by synergizing microtopographic cues and chiral nematics of cells

Topographical cues have been widely used to facilitate cell fusion in skeletal muscle formation. However, an unexpected yet consistent chiral orientation of myotubes deviating from the groove boundaries is commonly observed but has long been unattended. In this study, we report a method to guide the formation of skeletal myotubes into scalable and controlled patterns. By inducing C2C12 myoblasts onto grooved patterns with different widths (from 0.4 to 200 μm), we observed an enhanced chiral orientation of cells developing on wide grooves (50 and 100 μm width) since the first day of induction. Active chiral nematics of cells involving cell migration and chiral rotation of the cell nucleus subsequently led to a unified chiral orientation of the myotubes. Importantly, these chiral myotubes were formed with enhanced length, diameter, and contractility on wide grooves. Treatment of latrunculin A (Lat A) suppressed the chiral rotation and migration of cells as well as the myotube formation, suggesting the essence of chiral nematics of cells for myogenesis. Finally, by arranging wide grooved/striped patterns with corresponding compensation angles to synergize microtopographic cues and chiral nematics of cells, intricate and scalable patterns of myotubes were formed, providing a strategy for engineering skeletal muscle tissue formation.

241Am and 245Cm as candidates for the ROT effect investigation

Shifts of angular distributions of α-particles are calculated for induced fission of 241Am and 245Cm nuclei by slow polarized neutrons. This shift is called the ROT effect, since its manifestation is directly related to the oriented rotation of the nuclei. It is shown that at certain neutron energies, the magnitude of the ROT effect can be two times higher than the maximum effect detected to date. In addition, experiments with these nuclei may allow us to see the predominant rotation of the fissionable nucleus in the opposite direction to that observed in all previously studied isotopes.

Photometry of comet 29P/Schwassmann–Wachmann 1 in 2012–2019

The analysis of photometrical observations of comet 29P/Schwassmann–Wachmann 1 is presented. The broadband observations were carried out for 15 nights from 2012 to 2019 at the Lisnyky observational station of Taras Shevchenko National University of Kyiv. Apparent magnitudes and dust productivity level Afρ in filter R were calculated. Middle and height dust activity of the comet is characterized by parameter Afρ which varied from 1246 to 17563 cm during all periods of observation. Based on the morphological analysis, four jet-like structures were detected in the coma on almost all dates. Using the geometrical model for the jet structure interpretation during all observation sets, we obtained following results: the nucleus rotation period of 57±2days, the rotational axis orientation, the locations of active regions for four jet-like structures within a narrow belt near the equator.

Posterior polar cataract: Hydrodissection and nucleus rotation in manual small-incision cataract surgery not a taboo with proper fluidics.

A posterior polar cataract is a discoid posterior polar plaque-like cataract with a thin and fragile to absent posterior capsule with adherent acellular opacity to the capsule reported in the literature. It is a stationary or slowly progressive opacity. A higher risk of complications such as posterior capsular tear and nucleus drop makes this a challenging surgery. The techniques described in the literature include bimanual irrigation aspiration, leaving the plaque for later Yag, bimanual micro phaco, Lambda technique with dry aspiration, Phaco if opacity <4 mm and soft nucleus, pars plana vitrectomy (PPV), pars plana lensectomy (PPL) if opacity >4 mm and soft nucleus, intra-capsular cataract extraction (ICCE) and scleral fixated intraocular lens (IOL) if opacity >4 mm with the hard nucleus, viscodissection, 3 ports PPL, PPV, low parameters phaco, modified epinucleus removal, inverse horse-shoe technique, standard phacoemulsification, chip and flip for soft cataracts, stop and chop for hard cataracts, layer-by-layer phacoemulsification, standard lens aspiration, pars plicata posterior vitrecto-rhexis, manual small-incision cataract surgery, and conventional extracapsular extraction. A posterior capsule rupture rate of 0 to 36% is reported in different series for cataract extraction. To prevent this dreaded complication, surgeons used many modifications. Minimal hydrodissection in posterior polar cataract extraction was described by Fine et al. The authors describe a technique of low flow manual small-incision cataract surgery with minimal hydrodissection and nucleus rotation with no associated posterior capsule rent. This demonstrates that if the fluidics is understood and corrected, then minimal hydrodissection and nucleus rotation is not taboo in posterior polar cataract extraction by manual small-incision cataract surgery.

The Stop and Press Technique; an Occlusion Free Stop-and-Chop Technique in Cataract Patients with Soft to Moderate Nuclei.

The stop-and-chop technique, which involves occlusion and chopping using vacuum to stabilize the nucleus, is an excellent combination of the divide-and-conquer and phaco-chop techniques. However, effectively chopping an un-solid (soft to moderate) nucleus is not easy, since the optimal vacuum to hold an un-solid nucleus is often associated with breaking of occlusion and aspiration of the nucleus. We modified the stop-and-chop technique such that occlusion and tight nucleus holding using ultrasound (US) power is not necessary. After completing the central groove and cracking the nucleus into two hemi-sections, the right nucleus half is chopped without nucleus rotation and occlusion. The right hemi-nucleus is stabilized by pressing against the right sac with the US tip without occlusion. Since this technique can reduce the risk of nucleus perforation and posterior capsular rupture, the surgeons can place the US tip firmly in a deep position, which provide safe and efficient nucleus division.

Enhanced moments of inertia for rotation in neutron-rich nuclei

Ground-state moments of inertia (MoI) are investigated for approximately 1700 even–even nuclei from the proton drip line to the neutron drip up to Z=120 and N=184. The cranked Hartree–Fock–Bogoliubov equation is solved in the coordinate space using the Skyrme and pairing energy density functionals. This model well describes the available experimental data of the first excited Iπ=2+ state energy of more than 300 nuclides possessing appreciable deformation. The MoI is found to greatly increase near the drip line, whereas the deformation is found to be not as strong as estimated by the empirical relation when the pairing functional including the isovector-density dependence is adopted. The currently used pairing functionals produce large uncertainties in the prediction of E(21+) values near the neutron drip line.

Shape Changes in Odd-Even Osmium Isotopes

This paper has calculated the energy levels of 185-187-189Os isotopes using the projected shell model (PSM). Yrast Spectrum, nucleus rotation frequency and the ratio of reduced electromagnetic transition probabilities, B(E2)/B(M1) plots versus spin for understanding the structure of multi-quasiparticle band up to the spins 47/2+, 33/2+ and 31/2+ for these isotopes, are plotted, respectively. It was found that in the spin ranges 35/2+-39/2+, 31/2+-33/2+, and 27/2+-29/2+, due to 3-quasiparticle band-crossing, simultaneously by increasing rotational inertia of the nucleus, nucleus rotation frequency decreases greatly and as an important result, B(E2)/B(M1) ratio, the electrical properties of the nucleus in these spins increase. Indeed, in these isotopes, observed that by increasing neutron number, the deformation parameter, ε2 decreases as well, and by increasing spin in especial spins, due to nucleon alignment phenomenon, the nucleus rotational behavior decreases inverse the vibration mode.

New advances in medical imaging technology for the evaluation of anthracycline-induced cardiotoxicity.

New advances in medical imaging technology for the evaluation of anthracycline-induced cardiotoxicity.

A cytoskeletal vortex drives phage nucleus rotation during jumbo phage replication in E.coli.

Nucleus-forming jumbo phages establish an intricate subcellular organization, enclosing phage genomes within a proteinaceous shell called the phage nucleus. During infection in Pseudomonas, some jumbo phages assemble a bipolar spindle of tubulin-like PhuZ filaments that positions the phage nucleus at midcell and drives its intracellular rotation. This facilitates the distribution of capsids on its surface for genome packaging. Here we show that the Escherichia coli jumbo phage Goslar assembles a phage nucleus surrounded by an array of PhuZ filaments resembling a vortex instead of a bipolar spindle. Expression of a mutant PhuZ protein strongly reduces Goslar phage nucleus rotation, demonstrating that the PhuZ cytoskeletal vortex is necessary for rotating the phage nucleus. While vortex-like cytoskeletal arrays are important in eukaryotes for cytoplasmic streaming and nucleus alignment, this work identifies a coherent assembly of filaments into a vortex-like structure driving intracellular rotation within the prokaryotic cytoplasm.

Hubble Space Telescope Observations of Active Asteroid P/2020 O1 (Lemmon-PANSTARRS)

We present Hubble Space Telescope observations of active asteroid P/2020 O1 taken to examine its development for a year after perihelion. We find that the mass loss peaks at ≲1 kg s−1 in 2020 August and then declines to nearly zero over four months. Long-duration mass loss (∼180 days) is consistent with a sublimation origin, indicating that this object is likely an ice-bearing main-belt comet. Equilibrium sublimation of water ice from an area as small as 1580 m2 can supply the observed mass loss. Time-series photometry shows tentative evidence for extremely rapid rotation (double-peaked period <2 hr) of the small nucleus (effective radius ∼420 m). Ejection velocities of 0.1 mm particles are comparable to the 0.3 m s−1 gravitational escape speed from the nucleus, while larger particles are ejected at speeds less than the escape velocity. These properties are consistent with the sublimation of near-surface ice aided by centripetal acceleration. If water-ice sublimation is confirmed, P/2020 O1 would be an icy asteroid with the smallest semimajor axis (highest temperature), setting new bounds on the distribution of ice in the asteroid belt.

Dynamics of rotation in chiral nuclei

The dynamics of chiral nuclei is investigated for the first time with the time-dependent and tilted axis cranking covariant density functional theories on a three-dimensional space lattice in a microscopic and self-consistent way. The experimental energies of the two pairs of the chiral doublet bands in $^{135}$Nd are well reproduced without any adjustable parameters beyond the well-defined density functional. A novel mechanism, i.e., chiral precession, is revealed from the microscopic dynamics of the total angular momentum in the body-fixed frame, whose harmonicity is associated with a transition from the planar into aplanar rotations with the increasing spin. This provides a fully microscopic and dynamical view to understand the chiral excitations in nuclei.

Resolution of a possible misinterpretation of the nuclear excitation mode along the yrast line: An investigation on the evolution of rotation and vibration

An empirical approach, called E-GOS ($E$-gamma over spin) curves, which is used for discerning the evolution between vibration and rotation in nuclei as a function of spin, is discussed. Considering the possible mechanisms and the results of total-Routhian-surface calculations, we find that the decrease in an E-GOS plot may be misinterpreted as the onset of vibration behavior along the yrast line. The insufficiency of the vibration-like criterion of the E-GOS curves to determine the transition from rotation to vibration is emphasized. It is pointed out that the crossing between the ground-state and $S$ bands, especially with a strong interaction, will be responsible for such vibration-like evolution of nuclear excitation modes.