Contributions Of Rotation Research Articles

Experimental investigation on aerodynamic noise of a small-scale multi-blade centrifugal fan

In this study, the aerodynamic noise of a small-scale centrifugal fan was experimentally investigated using acoustic testing techniques and time-resolved stereoscopic particle image velocimetry (SPIV). During the acoustic experiments, both far-field noise and near-field pressure fluctuations of the test fan were measured. The overall far-field noise towards the fan inlet side was found to be higher than that of the back side. The pressure fluctuations on the fan upper casing exceeded those on the side wall due to the uncontracted volute tongue, indicating pronounced flow-to-wall interactions. Moreover, based on a simultaneous measurement, the coherence between the near-field pressure fluctuations and far-field noise highlighted the significant contributions of impeller rotation to noise radiation. SPIV measurements uncovered the time-averaged and transient flow fields at the fan's inlet and outlet. The time-averaged results demonstrated the concentrated inlet flow and outlet flow separation, leading to high flow unsteadiness. Transient flow fields displayed an asymmetric jet-wake region characterized by both quasi-steady flow and rotational flow behaviours. The instantaneous flow results were analyzed using the dynamic mode decomposition (DMD) method, which clearly recognized the jet-wake patterns with frequencies corresponding to the rotational frequency. The observed consistency in frequency characteristics among noise, pressure fluctuations, and unsteady flow affirms that flow dynamics are crucial to the primary noise mechanisms.

Rod Rotation with Outrigger Is Substantial for Correcting Apical Hypokyphosis in Patients with Adolescent Idiopathic Scoliosis: Novel Outrigger Device for Concave Rod Rotation

The apical hypokyphosis of scoliotic patients is thought to lead to decreased lung capacity and cause shortness of breath. Additionally, concave rod curve reduction is a problem in the correction of apical hypokyphosis in posterior spinal fusion surgery in adolescent idiopathic scoliosis (AIS). We investigated the contributions of rod rotation (RR) with an outrigger device, followed by differential rod contouring (DRC) with the outrigger attached to the concave rod, designed to prevent concave rod curve-flattening. We analyzed and compared the results of segmental pedicle screw fixation without the outrigger in 41 AIS patients with thoracic curves (Lenke type I, 25; type II, 16) to those corrected using the outrigger in 36 patients (Lenke type I, 24; type II,12). The changes in the Cobb angle, apical kyphosis of five vertebrae, thoracic kyphosis (TK, T4–12), correction rate, correction angle of apical vertebral rotation, spinal penetration index (SPi), and rib hump index (RHi) before and after surgery were measured, and the contribution of the outrigger was analyzed. The mean scoliosis correction rates without and with the outrigger were 72.1° and 75.6°, respectively (p = 0.03). Kyphosis of the five apical vertebrae and TK were significantly greater in the surgery with the outrigger (p = 0.002). Significantly greater improvements in SPi and RHi were also noted in the surgery with the outrigger (p < 0.05). The use of concave RR and convex DRC with the outrigger appear to be advantageous for correcting apical hypokyphosis, followed by the subsequent formation of TK. As a result, breathing problems are less likely to occur during daily life because of improvements in SPi and RHi.

Spatial and temporal variability of 21st century sea level changes

SUMMARY Mass loss from polar ice sheets is becoming the dominant contributor to current sea level changes, as well as one of the largest sources of uncertainty in sea level projections. The spatial pattern of sea level change is sensitive to the geometry of ice sheet mass changes, and local sea level changes can deviate from the global mean sea level change due to gravitational, Earth rotational and deformational (GRD) effects. The pattern of GRD sea level change associated with the melting of an ice sheet is often considered to remain relatively constant in time outside the vicinity of the ice sheet. For example, in the sea level projections from the most recent IPCC sixth assessment report (AR6), the geometry of ice sheet mass loss was treated as constant during the 21st century. However, ice sheet simulations predict that the geometry of ice mass changes across a given ice sheet and the relative mass loss from each ice sheet will vary during the coming century, producing patters of global sea level changes that are spatiotemporally variable. We adopt a sea level model that includes GRD effects and shoreline migration to calculate time-varying sea level patterns associated with projections of the Greenland and Antarctic Ice Sheets during the coming century. We find that in some cases, sea level changes can be substantially amplified above the global mean early in the century, with this amplification diminishing by 2100. We explain these differences by calculating the contributions of Earth rotation as well as gravitational and deformational effects to the projected sea level changes separately. We find in one case, for example, that ice gain on the Antarctic Peninsula can cause an amplification of up to 2.9 times the global mean sea level equivalent along South American coastlines due to positive interference of GRD effects. To explore the uncertainty introduced by differences in predicted ice mass geometry, we predict the sea level changes following end-member mass loss scenarios for various regions of the Antarctic Ice Sheet from the ISMIP6 model ensemblely, and find that sea level amplification above the global mean sea level equivalent differ by up to 1.9 times between different ice mass projections along global coastlines outside of Greenland and Antarctica. This work suggests that assessments of future sea level hazard should consider not only the integrated mass changes of ice sheets, but also temporal variations in the geometry of the ice mass changes across the ice sheets. As well, this study highlights the importance of constraining the relative timing of ice mass changes between the Greenland and Antarctic Ice Sheets.

Contributions of Rotation, Expansion and Line Broadening to the Morphology and Kinematics of the Inner CSE of Oxygen-rich AGB Star R Hya

We use archival ALMA observations of the CO(2–1) and SiO(5–4) molecular line emissions of AGB star R Hya to illustrate the relative contributions of rotation, expansion and line broadening to the morphology and kinematics of the circumstellar envelope (CSE) within some ∼70 au (∼0.″5) from the centre of the star. We give evidence for rotation and important line broadening to dominate the inner region, within ∼14 au (∼100 mas) from the centre of the star. The former is about an axis that projects a few degrees west of north and has a projected rotation velocity of a few km s−1. The latter occurs within some 7–14 au (50–100 mas) from the centre of the star, with the line width reaching two to three times its value outside this region. We suggest that it is caused by shocks induced by stellar pulsations and convective cell granulation. We show the importance of properly accounting for the observed line broadening when discussing rotation and evaluating the radial dependence of the rotation velocity.

Ferrite materials with high saturation magnetic induction intensity and high permeability for magnetic field energy harvesting: Magnetization mechanism and Brillouin function temperature characteristics

Manganese-zinc (MnZn) ferrites play an indispensable role in energy transform and harvesting. It is notable to mention that the combined enhancement of initial permeability (μi), saturation magnetic induction (Bs) and Curie temperature (Tc) is conducive to improving the output power and safety of magnetic field energy harvesting devices. In this paper, high permeability MnZn ferrites were synthesized by a conventional oxide ceramic method. The thermomagnetic curves of MnZn ferrites were fitted according to the Néel molecular field theory (NMFT) and the Brillouin function. Then the molecular field coefficient γaa, γab, γbb, and Tc were calculated. Aiming at the magnetization mechanism of permeability, the contributions of domain wall motion and spin rotation were analyzed by fitting the complex permeability spectrum. Furthermore, the temperature characteristics of μi and Bs are analyzed, and we simulated and compared the effect of different magnetic properties of MnZn ferrites on the output of non-invasive magnetic field harvester. The MnZn ferrites with superior comprehensive performance own potential applications for non-invasive magnetic field harvester.

Contributions of Body Segments to the Toe Velocity during Taekwondo Roundhouse Kick

The roundhouse kick is the most commonly executed kick in Taekwondo competitions. Because it is the fastest kick among kicking techniques and can easily change its motion on the basis of the opponent’s motion, the roundhouse kick is suitable for scoring points. To explore the functional role of segmental movements during the roundhouse kick, this study aimed to investigate the effects of various footwork techniques on biomechanical contributions of body segments to toe velocity during roundhouse kicks. Ten elite Taekwondo athletes performed roundhouse kicks with different footwork positions. The contributions of body segments to the toe velocity were obtained through 3D motion analysis. Results were compared by repeated measures analysis of variance (ANOVA), and there were significant differences in the contributions of whole-body movement, trunk movement, trunk rotation, and toe velocity. It was concluded that in the minimum knee flexion (MKF) event, for all types of footwork, thigh rotation showed the most significant contribution (51–64.4%), followed by trunk rotation (16.7–29.9%) and whole-body movement (5.1–13.4%). However, in the impact event, the contribution of thigh rotation decreased, while the contribution of calf rotation increased significantly.

A nonlinear viscoelasticity theory for nematic liquid crystal elastomers

Liquid crystal elastomers (LCE) are elastomeric networks with mesogen moieties that can reorient and order in response to thermomechanical loads. Experiments have shown that the stress response of nematic LCEs is rate-dependent and exhibits large hysteresis upon load–unload. In this work, we developed a theory for the large deformation viscoelastic behavior of monodomain nematic elastomers that separately incorporates the hypothesized dissipation mechanisms of viscous mesogen rotation and viscoelastic network deformation. The theory is specialized to the case of a homogeneous director field and applied to investigate the contributions of the viscous director rotation and network deformation mechanisms in the case of the uniaxial stress response of monodomain materials with director orientation parallel and perpendicular to the loading axis.

Reduced Movement Variability and Kinematics Changes During a Hand to Head Movement are Associated with Improved Outcome Following Superior Capsular Reconstruction (232)

Objectives:Patients with irreparable rotator cuff tears (RCT) exhibit functional limitations including limited ability to perform functional tasks such as combing their hair. One viable treatment is superior capsular reconstruction (SCR). SCR has been shown to restore stability of the glenohumeral (GH) joint in cadavers1, but its effect on in vivo scapular and humeral motion is unknown. The aims of this study were to determine the effect of SCR on in vivo scapular and humeral kinematics during a functional hand to head motion and to identify associations between shoulder kinematics and patient-reported outcomes (PROs). We hypothesized that moving the hand to the back of the head would be accomplished by using more GH based movement including rotation and abduction, and less scapular motion after SCR, and there would be a positive correlation between kinematics changes and improved PROs.Methods:Ten patients (8M, 2F, age 63 ± 7 years) with irreparable RCT provided informed consent to participate in this prospective IRB-approved study. American Shoulder and Elbow Surgeon (ASES), Disability of the Arm Shoulder and Hand (DASH), and Western Ontario Rotator Cuff Index (WORC) surveys were completed before (PRE) and 1-year (1YR-POST) after SCR. Participants were seated and instructed to move their hand from their lap to the back of their head while synchronized biplane radiographs of the shoulder were collected PRE and 1YR-POST at 50 images/s for 3 separate trials. Six degree of freedom GH and scapular kinematics were determined with sub-millimeter accuracy by matching subject-specific CT-based bone models of the humerus and scapula to the synchronized radiographs using a validated volumetric tracking technique3. The contributions of humeral abduction, plane of elevation and internal/external (I/E) rotation relative to the scapula, as well as scapular upward rotation, protraction, and tilt, were calculated for each subject before and after SCR. Differences in rotational contributions from PRE to POST were evaluated using a paired t-test. Variability in rotational contributions was characterized by the inter-subject standard deviation in rotational component contributions to the movement. Correlations among changes in the contribution of each rotation component and between the contribution of each rotation component and PROs were evaluated with Pearson’s correlation coefficients. Significance was set at p < 0.05 for all tests.Results:No differences in contribution to motion were identified in any of the rotational components from PRE to POST (all p > 0.15, Figure 1). Inter-subject variability in rotational contributions to the movement decreased in 5 of the 6 rotational components from PRE to 1YR-POST (Table 1; Figure 1). The PRE to 1YR POST change in contribution from GH abduction was positively correlated to the change in contribution from GH I/E rotation (Figure 2, R = 0.8, p = 0.001) and negatively correlated to the change in contribution from scapular protraction (Figure 2, R = -0.94, p = 0.001). ASES scores were negatively correlated with abduction contribution PRE (R = -0.65, p = 0.043), and positively correlated with plane of elevation PRE (R = 0.685, p = 0.03). Changes in the plane of elevation contribution were also positively correlated with changes in ASES scores (R = 0.635, p = 0.048).Conclusions:This is the first study to report GH and scapular kinematics when performing the functional task of placing the hand to the back of the head. Changes in contributions to the motion were inconsistent across subjects, making it difficult to find differences from PRE to POST. However, inter-subject variation was reduced following surgery, suggesting the participants’ movement strategy converged toward a more similar and possibly more efficient movement pattern following SCR. Increased contributions of glenohumeral rotation and abduction were offset by decreased scapular protraction and indicates SCR affects the contributions from these three rotations, partially supporting our first hypothesis. In addition, increased GH plane of elevation contribution following surgery was associated with improved ASES scores supporting our second hypothesis. This may be consistent with improved glenohumeral kinematics and efficiency of movement during a functional task following SCR. Future work will investigate GH and scapular kinematics in healthy individuals performing the hand to head movement to determine if movement strategy is closer to healthy after SCR.

Morpho-kinematics of the circumstellar envelope of the AGB star R Dor: a global view

ABSTRACT We analyse new ALMA observations of the 29SiO (ν = 0, J = 8–7) and SO2 (ν = 0, 343,31−342,32) line emissions of the circumstellar envelope (CSE) of the oxygen-rich asymptotic giant branch (AGB) star, R Dor. With a spatial resolution of ∼2.3 au, the observations cover distances below ∼30 au from the star providing a link between earlier observations and clarifying some open issues. The main conclusions are the following. (i) Rotation is confined below ∼15 au from the star, with velocity reaching a maximum below 10 au and morphology showing no significant disc-like flattening. (ii) In the south-eastern quadrant, a large Doppler velocity gas stream is studied in more detail than previously possible and its possible association with an evaporating planetary companion is questioned. (iii) A crude evaluation of the respective contributions of rotation, expansion and turbulence to the morpho-kinematics is presented. Significant line broadening occurs below ∼12 au from the star and causes the presence of high Doppler velocity components near the line of sight pointing to the centre of the star. (iv) Strong absorption of the continuum emission of the stellar disc and its immediate dusty environment is observed to extend beyond the disc in the form of self-absorption. The presence of a cold SiO layer extending up to some 60 au from the star is shown to be the cause. (v) Line emissions from SO, 28SiO, CO and HCN molecules are used to probe the CSE up to some 100 au from the star, revealing the presence of two broad back-to-back outflows, the morphology of which is studied in finer detail than in earlier work.

When Gas Dynamics Decouples from Galactic Rotation: Characterizing ISM Circulation in Disk Galaxies

Abstract In galactic disks, galactic rotation sets the bulk motion of gas, and its energy and momentum can be transferred toward small scales. Additionally, in the interstellar medium, random and noncircular motions arise from stellar feedback, cloud–cloud interactions, and instabilities, among other processes. Our aim is to comprehend to what extent small-scale gas dynamics is decoupled from galactic rotation. We study the relative contributions of galactic rotation and local noncircular motions to the circulation of gas, Γ, a macroscopic measure of local rotation, defined as the line integral of the velocity field around a closed path. We measure the circulation distribution as a function of spatial scale in a set of simulated disk galaxies and model the velocity field as the sum of galactic rotation and a Gaussian random field. The random field is parameterized by a broken power law in Fourier space, with a break at the scale . We define the spatial scale at which galactic rotation and noncircular motions contribute equally to Γ. For our simulated galaxies, the gas dynamics at the scale of molecular clouds is usually dominated by noncircular motions, but in the center of galactic disks galactic rotation is still relevant. Our model shows that the transfer of rotation from large scales breaks at the scale , and this transition is necessary to reproduce the circulation distribution. We find that , and therefore the structure of the gas velocity field, is set by the local conditions of gravitational stability and stellar feedback.

Evolving pulsation of the slowly rotating magnetic β Cep star ξ1 CMa

ABSTRACT Recent BRITE-Constellation space photometry of the slowly rotating, magnetic β Cep pulsator ξ1 CMa permits a new analysis of its pulsation properties. Analysis of the two-colour BRITE data reveals the well-known single pulsation period of 0.209 d, along with its first and second harmonics. A similar analysis of SMEI and TESS observations yields compatible results, with the higher precision TESS observations also revealing several low-amplitude modes with frequencies below 5 d−1; some of these are likely g modes. The phase lag between photometric and radial velocity maxima – equal to 0.334 cycles – is significantly larger than the typical value of 1/4 observed in other large-amplitude β Cep stars. The phase lag, as well as the strong dependence of phase of maximum light on wavelength, can be reconciled with seismic models only if the dominant mode is the fundamental radial mode. We employ all published photometric and radial velocity measurements, spanning over a century, to evaluate the stability of the pulsation period. The O−C diagram exhibits a clear parabolic shape consistent with a mean rate of period change $\dot{P}=0.34\pm 0.02$ s cen−1. The residuals from the best-fitting parabola exhibit scatter that is substantially larger than the uncertainties. In particular, dense sampling obtained during the past ∼20 yr suggests more complex and rapid period variations. Those data cannot be coherently phased with the mean rate of period change, and instead require $\dot{P}\sim 0.9$ s cen−1. We examine the potential contributions of binarity, stellar evolution, and stellar rotation and magnetism to understand the apparent period evolution.

First-order approximation to the Boltzmann–Curtiss equation for flows with local spin

The first-order approximation to the solution of the Boltzmann–Curtiss transport equation is derived. The resulting distribution function treats the rotation or gyration of spherical particles as an independent classical variable, deviating from the quantum mechanical treatment of molecular rotation found in the Wang Chang–Uhlenbeck equation. The Boltzmann–Curtiss equation, therefore, does not treat different rotational motions as separate molecular species. The first-order distribution function yields momentum equations for the translational velocity and gyration, which match the form of the governing equations of morphing continuum theory (MCT), a theory derived from the approach of rational continuum thermomechanics. The contributions of the local rotation to the Cauchy stress and the viscous diffusion are found to be proportional to an identical expression based on the relaxation time, number density, and equilibrium temperature of the fluid. When gyration is equated to the macroscopic angular velocity, the kinetic description reduces to the first-order approximation for a classical monatomic gas, and the governing equations match the form of the Navier–Stokes equations. The relaxation time used for this approximation is shown to be more complex due to the additional variable of local rotation. The approach of De Groot and Mazur is invoked to give an initial approximation for the relaxation of the gyration. The incorporation of this relaxation time, and other physical parameters, into the coefficients of the governing equations provides a more in-depth physical treatment of the new terms in the MCT equations, allowing for experimenters to test these expressions and get a better understanding of new coefficients in MCT.

Breathing with floating ribs: XROMM analysis of lung ventilation in savannah monitor lizards.

The structures and functions of the vertebrate lung and trunk are linked through the act of ventilation, but the connections between these structures and functions are poorly understood. We used X-ray reconstruction of moving morphology (XROMM) to measure rib kinematics during lung ventilation in three savannah monitor lizards (Varanus exanthematicus). All of the dorsal ribs, including the floating ribs, contributed to ventilation; the magnitude and kinematic pattern showed no detectable cranial-to-caudal gradient. The true ribs acted as two rigid bodies connected by flexible cartilage, with the vertebral rib and ventromedial shaft of each sternal rib remaining rigid and the cartilage between them forming a flexible intracostal joint. Rib rotations can be decomposed into bucket handle rotation around a dorsoventral axis, pump handle rotation around a mediolateral axis and caliper motion around a craniocaudal axis. Dorsal rib motion was dominated by roughly equal contributions of bucket and pump rotation in two individuals and by bucket rotation in the third individual. The recruitment of floating ribs during ventilation in monitor lizards is strikingly different from the situation in iguanas, where only the first few true ribs contribute to breathing. This difference may be related to the design of the pulmonary system and life history traits in these two species. Motion of the floating ribs may maximize ventilation of the caudally and ventrolaterally positioned compliant saccular chambers in the lungs of varanids, while restriction of ventilation to a few true ribs may maximize crypsis in iguanas.

Pelvic girdle mobility of cryptodire and pleurodire turtles during walking and swimming.

Movements of the pelvic girdle facilitate terrestrial locomotor performance in a wide range of vertebrates by increasing hind limb excursion and stride length. The extent to which pelvic movements contribute to limb excursion in turtles is unclear because the bony shell surrounding the body presents a major obstacle to their visualization. In the Cryptodira, which are one of the two major lineages of turtles, pelvic anatomy indicates the potential for rotation inside the shell. However, in the Pleurodira, the other major suborder, the pelvis shows a derived fusion to the shell, preventing pelvic motion. In addition, most turtles use their hind limbs for propulsion during swimming as well as walking, and the different locomotor demands between water and land could lead to differences in the contributions of pelvic rotation to limb excursion in each habitat. To test these possibilities, we used X-ray reconstruction of moving morphology (XROMM) to compare pelvic mobility and femoral motion during walking and swimming between representative species of cryptodire (Pseudemys concinna) and pleurodire (Emydura subglobosa) turtles. We found that the pelvis yawed substantially in cryptodires during walking and, to a lesser extent, during swimming. These movements contributed to greater femoral protraction during both walking and swimming in cryptodires when compared with pleurodires. Although factors related to the origin of pelvic-shell fusion in pleurodires are debated, its implications for their locomotor function may contribute to the restriction of this group to primarily aquatic habits.

Microstructure and Electromagnetic Properties of Ni-Zn-Co Ferrite up to 20 GHz

The present paper examines the relation between different developed microstructures and the microwave electromagnetic properties in Ni-Zn-Co ferrite. To this end, the Ni0.25Zn0.25Co0.5Fe2O4composition has been prepared with the conventional ceramic process with varied prefiringTP(750°C, 1000°C) and sinteringTStop temperatures (1200°C, 1250°C). When lower temperatures are applied in these production stages, incomplete microstructures with low density, higher porosity, or finer grains are achieved. On account of these features, the contributions of domain wall motion and spin rotation to the complex permeabilityμ⁎(f)move to higher frequencies, whereas microwave dielectric permittivityε⁎(f)is decreased. In particular in conjunction with the high Co content, the wall relaxation and spin resonance are interestingly forced to occur at 850 MHz and 8.05 GHz, respectively. Regarding the electromagnetic wave attenuation, the ferrite annealed at lower temperatures exhibits strong return loss peaks at higher frequencies, but without other performance improvement. We should notice that the variations in sintering temperatureTSyield the maximum changes in the recorded parameters, including the coercive field,μ⁎(f),andε⁎(f), indicating the inferior role of prefiringTPin Ni-Zn ferrite.

Titrating decision processes in the mental rotation task.

Shepard and Metzler's (1971) seminal mental-rotation task-which requires participants to decide if 1 object is a rotated version of another or its mirror image-has played a central role in the study of spatial cognition. We provide the first quantitative model of behavior in this task that is comprehensive in the sense of simultaneously providing an account of both error rates and the full distribution of response times. We used Brown and Heathcote's (2008) model of choice processing to separate out the contributions of mental rotation and decision stages. This model-based titration process was applied to data from a paradigm where converging evidence supported performance being based on rotation rather than other strategies. Stimuli were similar to Shepard and Metzler's block figures except a long major axis made rotation angle well defined for mirror stimuli, enabling comprehensive modeling of both mirror and normal responses. Results supported a mental rotation stage based on Larsen's (2014) model, where rotation takes a variable amount of time with a mean and variance that increase linearly with rotation angle. Differences in response threshold differences were largely responsible for mirror responses being slowed, and for errors increasing with rotation angle for some participants. (PsycINFO Database Record

From the Bay of Biscay to the High Atlas: Completing the anisotropic characterization of the upper mantle beneath the westernmost Mediterranean region

The knowledge of the anisotropic properties beneath the Iberian Peninsula and Northern Morocco has been dramatically improved since late 2007 with the analysis of the data provided by the dense TopoIberia broad-band seismic network, the increasing number of permanent stations operating in Morocco, Portugal and Spain, and the contribution of smaller scale/higher resolution experiments. Results from the two first TopoIberia deployments have evidenced a spectacular rotation of the fast polarization direction (FPD) along the Gibraltar Arc, interpreted as an evidence of mantle flow deflected around the high velocity slab beneath the Alboran Sea, and a rather uniform N100°E FPD beneath the central Iberian Variscan Massif, consistent with global mantle flow models taking into account contributions of surface plate motion, density variations and net lithosphere rotation. The results from the last Iberarray deployment presented here, covering the northern part of the Iberian Peninsula, also show a rather uniform FPD orientation close to N100°E, thus confirming the previous interpretation globally relating the anisotropic parameters to the LPO of mantle minerals generated by mantle flow at asthenospheric depths. However, the degree of anisotropy varies significantly, from delay time values of around 0.5s beneath NW Iberia to values reaching 2.0s in its NE corner. The anisotropic parameters retrieved from single events providing high quality data also show significant differences for stations located in the Variscan units of NW Iberia, suggesting that the region includes multiple anisotropic layers or complex anisotropy systems. These results allow to complete the map of the anisotropic properties of the westernmost Mediterranean region, which can now be considered as one of best constrained regions worldwide, with more than 300 sites investigated over an area extending from the Bay of Biscay to the Sahara platform.

Dual-laser homo-FRET on the cell surface

Inhomogeneous broadening and red-edge effects have been detected on a highly mobile system of fluorescently conjugated mAbs targeted to cell surface receptors. By exploiting site-selective spectroscopy and the characteristic loss of homo-FRET on increasing excitation and decreasing emission wavelengths, contributions of physical rotation and homo-FRET to the depolarization of fluorescence anisotropy have been separated. Absolute homo-FRET efficiency has been determined by ratioing two anisotropies: a homo-FRET-sensitive one, which is excited at the absorption main band and detected at the long wavelength region of emission, and a homo-FRET-insensitive one, which is excited at the long wavelength region of absorption and detected at the short wavelength region of emission. Because the anisotropies are simultaneously detected in a unified detection scheme of a dual T-format arrangement, the method is applicable for the real-time tracking of dynamical changes of physical rotations and proximities. The utility of the method is demonstrated in the context of the MHCII molecule and the heavy and light chains of the MHCI molecule, a system of three receptors with well-characterized close mutual proximities. Although the method is presented for a flow cytometer, it can also be realized in a fluorescence microscope capable for dual-laser excitation and dual-anisotropy detection.

Low-temperature rate coefficients for vibrational relaxation of (3)Σ(u)(+)Rb2 molecules by (3)He and (4)He atoms.

We present quantum-scattering calculations of (4)He and (3)He colliding with (87)Rb2. For both helium isotopes, the elastic and inelastic rate coefficients are strongly influenced by the J = 1 partial wave. For the lighter isotope, a strong resonance feature of the J = 1 partial wave is responsible for an extremely efficient vibrational relaxation process. We also perform bound-state calculations of the Rb2He complex for even Rb permutation symmetry and nonzero total angular momentum. The global Rb2He (3)Σu(+) potential-energy surface used supports four bound states for (4)He and a single one for (3)He. We propose an analysis of the (87)Rb2(4)He spectrum separating the contributions of Rb2 rotation and helium motion.

Competition between antimagnetic and core rotation in109Cdwithin covariant density functional theory

The tilted axis cranking model based on covariant density functional theory is used to investigate the negative-parity yrast sequence in ${}^{109}\mathrm{Cd}$. The energy spectra, the relation between spin and rotational frequency, deformation parameters, and reduced $E2$ transition probabilities are calculated, which are in good agreement with available data. The orientation of angular momentum is also extracted and discussed in detail. By investigating microscopically the orientation of angular momentum and the contributions of antimagnetic rotation and core rotation to the total angular momentum, we find that ${}^{109}\mathrm{Cd}$ should be a critical transitional nucleus between the antimagnetic and core rotations.