Root Mean Square Radius Research Articles

Insight of the viscometric behavior of pullulan and curdlan derivative solutions: Effect of the nature and salt concentration

Increasing interest for polysaccharides investigation is based on their friendly behavior with environment and living organisms. The chemical structure, molar mass, chain conformation adopted in different media plays an important role for their performances in various practical applications. In this context, the viscometric behavior of two cationic pullulan and curdlan derivatives has been followed in water and salt solutions. The biopolyelectrolytes contain trimethylammonium propyl carbamate groups and trimethyl-N-(2-hydroxypropyl)ammonium ones attached to the backbone of pullulan and curdlan, respectively. The viscosity data have been interpreted in terms of the Wolf model. From the estimated values of the hydrodynamic parameters expressed by intrinsic viscosity [η], the hydrodynamic interaction parameter (b), etc., the dependence of the polyion conformation on the polyelectrolyte concentration and salt nature and concentration has been revealed; [η] decreased and b increased with increasing salt concentration and counterions valence. The viscosity data obtained in salt solutions allowed the estimation of the stiffness parameter (B), the expansion factors for the viscosity (αη) and for the root mean-square radius of gyration, αS, etc. and the establishment of counterions binding type as an “atmospheric ionic” one for the mononovalent counterions.

Structure and decay chain of fermium isotopes using relativistic mean-field approach

In this paper, we have analyzed the ground state structural properties of fermium-isotopes in the mass range [Formula: see text] within the relativistic mean-field with NL3[Formula: see text] and Relativistic Hartree–Bogoliubov approach with DD-ME2 parameter sets. The bulk properties, such as binding energy, root mean-square charge radius, quadruple deformation parameter, chemical potentials, two-neutron separation energy and differential two- neutron separation energy, are estimated for the above Fm- isotopic chain. All the calculated observables are compared with finite range droplet model (FRDM) predictions and experimental data wherever available. The analysis predicts the existence of shell closure in the neutron-rich region of the isotopic chain at [Formula: see text]. The decay properties such as the [Formula: see text]-decay energy and corresponding half-life for three decay chains i.e. [Formula: see text]Fm, [Formula: see text]Fm and [Formula: see text]Fm are studied. Six different empirical formulae, namely; Viola-Seaborg, Royer, modified B. Alex Brown, Parkhomenko–Sobiczewski, Universal decay law and modified universal decay law are employed to ascertain the numerical dependency of the half-life for each decay energy. A comparative study of [Formula: see text]-values and half-lives for these decay chains gives a good signature of the calculated results. The half-life calculations of three decay chains suggest that [Formula: see text]Pu, [Formula: see text]Pu, [Formula: see text]Pu are shell closure nuclei having maximum half-lives, whereas [Formula: see text]Fm, [Formula: see text]Fm and [Formula: see text]Fm are shell stabilized with lower half-lives.

Erratum: Nucleon form factors and root-mean-square radii on a (10.8 fm)4 lattice at the physical point [Phys. Rev. D 99 , 014510 (2019)

We present the nucleon form factors and root-mean-square (RMS) radii measured on a (10.8 fm$)^4$ lattice at the physical point. We compute the form factors at small momentum transfer region in $q^2\le 0.102$ GeV$^2$ with the standard plateau method choosing four source-sink separation times $t_{\rm sep}$ from 0.84 to 1.35 fm to examine the possible excited state contamination. We obtain the electric and magnetic form factors and their RMS radii for not only the isovector channel but also the proton and neutron ones without the disconnected diagram. We also obtain the axial-vector coupling and the axial radius from the axial-vector form factor. We find that these three form factors do not show large $t_{\rm sep}$ dependence in our lattice setup. On the other hand, the induced pseudoscalar and pseudoscalar form factors show the clear effects of the excited state contamination, which affect the generalized Goldberger-Treiman relation.

Generalized Chou-Yang Model and Hadronic Radii

Generalized Chou-Yang model (GCYM) predicts electromagnetic form factors of several hadrons with varying magnitude of strangeness. By using these form factors, the root mean square (RMS) radii of the hadrons such as (π, p, ϕ, Λ, Σ+, Σ−and Ω−)are computed. It is found that there is consistency among the predicted RMS radii of pion and proton by GCYM (and other models) and experimental results. For all hadrons experimental results are not available. Also we find that results of GCYM and from other models are somewhat inconsistent for hadrons other than pion and proton. Though GCYM and other models do not agree for most of the hadrons but they have one similarity that the computed RMS radii seem decreasing with the increase in the strangeness level, separately for mesons as well as for baryons. The experimental results of hadrons other than pion and proton are needed to check the suitability of GCYM and other models as well as in probing the trend of decreasing radii with increase in strangeness content.

A Rubber-Tapping Robot Forest Navigation and Information Collection System Based on 2D LiDAR and a Gyroscope.

Natural rubber is widely used in human life because of its excellent quality. At present, manual tapping is still the main way to obtain natural rubber. There is a sore need for intelligent tapping devices in the tapping industry, and the autonomous navigation technique is of great importance to make rubber-tapping devices intelligent. To realize the autonomous navigation of the intelligent rubber-tapping platform and to collect information on a rubber forest, the sparse point cloud data of tree trunks are extracted by the low-cost LiDAR and a gyroscope through the clustering method. The point cloud is fitted into circles by the Gauss–Newton method to obtain the center point of each tree. Then, these center points are threaded through the Least Squares method to obtain the straight line, which is regarded as the navigation path of the robot in this forest. Moreover, the Extended Kalman Filter (EKF) algorithm is adopted to obtain the robot’s position. In a forest with different row spacings and plant spacings, the heading error and lateral error of this robot are analyzed and a Fuzzy Controller is applied for the following activities: walking along one row with a fixed lateral distance, stopping at fixed points, turning from one row into another, and collecting information on plant spacing, row spacing, and trees’ diameters. Then, according to the collected information, each tree’s position is calculated, and the geometric feature map is constructed. In a forest with different row spacings and plant spacings, three repeated tests have been carried out at an initial speed of 0.3 m/s. The results show that the Root Mean Square (RMS) lateral errors are less than 10.32 cm, which shows that the proposed navigation method provides great path tracking. The fixed-point stopping range of the robot can meet the requirements for automatic rubber tapping of the mechanical arm, and the average stopping error is 12.08 cm. In the geometric feature map constructed by collecting information, the RMS radius errors are less than 0.66 cm, and the RMS plant spacing errors are less than 11.31 cm. These results show that the method for collecting information and constructing a map recursively in the process of navigation proposed in the paper provides a solution for forest information collection. The method provides a low-cost, real-time, and stable solution for forest navigation of automatic rubber tapping equipment, and the collected information not only assists the automatic tapping equipment to plan the tapping path, but also provides a basis for the informationization and precise management of a rubber plantation.

Investigation of density and form factor of some F isotopes using Hartree-Fock and shell model calculations

Structure of unstable 21,23,25,26F nuclei have been investigatedusing Hartree – Fock (HF) and shell model calculations. The groundstate proton, neutron and matter density distributions, root meansquare (rms) radii and neutron skin thickness of these isotopes arestudied. Shell model calculations are performed using SDBAinteraction. In HF method the selected effective nuclear interactions,namely the Skyrme parameterizations SLy4, Skeσ, SkBsk9 andSkxs25 are used. Also, the elastic electron scattering form factors ofthese isotopes are studied. The calculated form factors in HFcalculations show many diffraction minima in contrary to shellmodel, which predicts less diffraction minima. The long tailbehaviour in nuclear density is noticeable seen in HF more than shellmodel calculations. The deviation occurs between shell model andHF results are attributed to the sensitivity of charge form factors tothe change of the tail part of the charge density. Calculations donefor the rms radii in shell model showed excellent agreement withexperimental values, while HF results showed an overestimation inthe calculated rms radii for 21,23F and good agreement for 25,26F. Ingeneral, it is found that the shell model and HF results have the samebehaviour when the mass number (A) increase.

Ground state binding energies and RMS radii of Λ in hypernuclei in the presence of spin-dependent potential

In recent years, the physics of hypernuclei has been in progress dramatically both in experiments and theories. In this regard, there have been considerable interests in the study of [Formula: see text]-particle 1s state in hypernuclei using relativistic quantum mechanics. Many theoretical results have been obtained numerically in the relativistic frameworks. In this work, using the relativistic Dirac equation, we study the properties of [Formula: see text]-particle in the hypernuclei analytically and, specifically, we determine its binding energies of ground state in a single [Formula: see text]-hypernuclei. The [Formula: see text]-N potential is considered as a spin-dependent term and the radial dependence of potential is approximated by a Gaussian function. For a more complete analysis, we will also compute the hypernuclei mass, its wave function and the root mean square (RMS) radii of [Formula: see text] orbits in [Formula: see text]-hypernuclear system.

Nucleon form factors and root-mean-square radii on a (10.8 fm)4 lattice at the physical point

We present the nucleon form factors and root-mean-square (RMS) radii measured on a ${(10.8\text{ }\text{ }\mathrm{fm})}^{4}$ lattice at the physical point. We compute the form factors at small momentum transfer region in ${q}^{2}\ensuremath{\le}0.102\text{ }\text{ }{\mathrm{GeV}}^{2}$ with the standard plateau method choosing four source-sink separation times ${t}_{\mathrm{sep}}$ from 0.84 to 1.35 fm to examine the possible excited state contamination. We obtain the electric and magnetic form factors and their RMS radii for not only the isovector channel but also the proton and neutron ones without the disconnected diagram. We also obtain the axial-vector coupling and the axial radius from the axial-vector form factor. We find that these three form factors do not show large ${t}_{\mathrm{sep}}$ dependence in our lattice setup, and those RMS radii are consistent with the experimental values. On the other hand, the induced pseudoscalar and pseudoscalar form factors show the clear effects of the excited state contamination, which affect the generalized Goldberger-Treiman relation.

Nuclear structure study of 20Ne, 24Mg, 28Si and 32S nuclei using Skyrme-Hartree-Fock method

The Skyrme–Hartree–Fock (SHF) method with the Skyrmeparameters; SKxtb, SGII, SKO, SKxs15, SKxs20 and SKxs25 havebeen used to investigate the ground state properties of some 2s-1dshell nuclei with Z=N (namely; 20Ne, 24Mg, 28Si and 32S) such as, thecharge, proton and matter densities, the corresponding root meansquare (rms) radii, neutron skin thickness, elastic electron scatteringform factors and the binding energy per nucleon. The calculatedresults have been discussed and compared with the availableexperimental data.

The nonstrange dibaryon and hidden-color effect in a chiral quark model

The exotic nonstrange \( \Delta\Delta\) dibaryon with \( I(J^{P}) = 0(3^{+})\) has been confirmed by the experimental data reported by WASA-at-COSY Collaboration, and the result is consistent with our theoretical prediction in the chiral SU(3) quark model and extended chiral SU(3) quark model, showing that the effect from hidden-color channel (CC is important. In the present work, we further investigate another exotic nonstrange \( \Delta\Delta\) dibaryon with \( I(J^{P}) = 3(0^{+})\) in the chiral SU(3) quark model that describes the energies of baryon ground states and the nucleon-nucleon (NN) scattering data satisfactorily. We perform a dynamical coupled-channel study of the \( \Delta\Delta\) -CC system with \( I(J^{P}) = 3(0^{+})\) within the framework of resonating group method (RGM). We find that the binding energy of \( I(J^{P}) = 3(0^{+})\) state is about 22.3 MeV and a root-mean-square radius (RMS) of 1.03 fm in single-channel calculation. Then we extend the model to include the CC channel to further study the \( I(J^{P}) = 3(0^{+})\) state and find that the binding energy is about 31.3 MeV and RMS is 0.97 fm in coupled-channel calculation. We can see that the CC channel coupling has a relatively large effect on this state. The color screening effect is further considered and we find that the bound state property will not change much. It is shown that the binding energy of this state is stably ranged around several tens of MeV; it means that its mass is always lower than the threshold of the \( \Delta\Delta\) channel and higher than the mass of \( N\Delta\pi\).

Understanding the structure of d*(2380) in chiral quark model

The structure and decay properties of d* have been detailedly investigated in both the chiral SU(3) quark model and the extended chiral SU(3) quark model that describe the energies of baryon ground states and the nucleon-nucleon (NN) scattering data satisfactorily. By performing a dynamical coupled-channels study of the system of ΔΔ and hidden-color channel (CC) with quantum numbers I(J P ) = 0(3+) in the framework of the resonating group method (RGM), we find that the d* has a mass of about 2.38-2.42 GeV and a root-mean-square radius (RMS) of about 0.76-0.88 fm. The channel wave function is extracted by a projection of the RGM wave function onto the physical basis, and the fraction of CC component in the d* is found to be about 66%-68%, which indicates that the d* is a hexaquark-dominated exotic state. Based on this scenario the partial decay widths of d* → d π 0 π 0 and d∗ → d π + π − are further explicitly evaluated and the total width is then obtained by use of the branching ratios extracted from the measured cross sections of other possible decay channels. Both the mass and the decay width of d* calculated in this work are compatible with the data (M ≈ 2380 MeV, Γ ≈ 70 MeV) reported by WASA-at-COSY Collaboration.

States of13C with abnormal radii

Differential cross-sections of the elastic and inelastic 13 C + α scattering were measured at E(α ) = 90 MeV. The root mean-square radii( >) of 13 C nucleus in the states: 8.86 (1/2− ), 3.09 (1/2+ ) and 9.90 (3/2− ) MeV were determined by the Modified diffraction model (MDM). The radii of the first two levels are enhanced compared to that of the ground state of 13 C, confirming the suggestion that the 8.86 MeV state is an analogue of the Hoyle state in 12 C and the 3.09 MeV state has a neutron halo. Some indications to the abnormally small size of the 9.90 MeV state were obtained.

Is d* a candidate for a hexaquark-dominated exotic state?**Supported by National Natural Science Foundation of China (11475181, 11105158, 11035006, 11165005), Key Project of Chinese Academy of Sciences (KJCX2-EW-N01), IHEP Innovation Fund (Y4545190Y2), One Hundred Person Project of the University of Chinese Academy of Sciences

We confirm our previous prediction of a d* state with I(JP) = 0(3+) [Phys. Rev. C 60, 045203 (1999)] and report for the first time based on a microscopic calculation that d* has about 2/3 hidden color (CC) configurations and thus is a hexaquark-dominated exotic state. By performing a more elaborate dynamical coupled-channels investigation of the ΔΔ-CC system within the framework of the resonating group method (RGM) in a chiral quark model, we find that the d* state has a mass of about 2.38–2.42 GeV, a root-mean-square radius (RMS) of 0.76–0.88 fm, and a CC fraction of 66%–68%. The last may cause a rather narrow width for the d* which, together with the quantum numbers and our calculated mass, is consistent with the newly observed resonance-like structure (M≈2380 MeV, Γ≈70 MeV) in double-pionic fusion reactions reported by the WASA-at-COSY Collaboration.

Cluster analysis for the probability of DSB site induced by electron tracks

To clarify the influence of bio-cells exposed to ionizing radiations, the densely populated pattern of the ionization in the cell nucleus is of importance because it governs the extent of DNA damage which may lead to cell lethality. In this study, we have conducted a cluster analysis of ionization and excitation events to estimate the number of double-strand breaks (DSBs) induced by electron tracks. A Monte Carlo simulation for electrons in liquid water was performed to determine the spatial location of the ionization and excitation events. The events were divided into clusters by using the density-based spatial clustering of applications with noise (DBSCAN) algorithm. The algorithm enables us to sort out the events into the groups (clusters) in which a minimum number of neighboring events are contained within a given radius. For evaluating the number of DSBs in the extracted clusters, we have introduced an aggregation index (AI). The computational results show that a sub-keV electron produces DSBs in a dense formation more effectively than higher energy electrons. The root-mean square radius (RMSR) of the cluster size is below 5nm, which is smaller than the chromatin fiber thickness. It was found that this size of clustering events has a high possibility to cause lesions in DNA within the chromatin fiber site.

Structural characterization and antitumor activity of a pectic polysaccharide from Codonopsis pilosula

A pectic polysaccharide (CPP1b) was at first isolated from Codonopsis pilosula. Sugar analysis revealed that CPP1b is composed of rhamnose (Rha), arabinose (Ara), galactose (Gal) and galacturonic acid (GalA) with a molar ratio of 0.25:0.12:0.13:2.51. The result of esterification assay showed that about 46.7±0.4% of carboxylic groups in GalA residues existed as methyl ester. Combined with chemical and spectroscopic analyses, a preliminary structure of CPP1b was proposed as follows: 1,4-linked α-d-GalpA and 1,4-linked α-d-GalpA6Me interspersed with rare 1,2-linked β-l-Rhap, 1,2,6-linked α-d-Galp and terminal α-l-Arap. CPP1b had an average molar mass and root-mean square radius (RMS) of 1.45×105Da and 29.7nm, respectively, and presented a linear random coil conformation in 0.9% NaCl. The ultrastructure of CPP1b was further investigated by transmission electron microscope (TEM) and scanning electron microscope (SEM). CPP1b exhibited obvious cytotoxicity to human lung adenocarcinoma A549 cells in a dose- and time-dependent manner.

Study on 222–226Th Isotopes in the Cranking Framework

The yrast spectra, quadrupole moments, quadrupole deformation parameters (β 2), non-axiality parameters (γ), root mean-square radii for protons and neutrons, occupation probabilities, moment of inertia (I), and B(E2) transition probabilities are calculated for 222–226Th in the cranked Hartree–Bogoliubov framework. The calculations employ a quadrupole-quadrupole plus pairing model of residual interaction operating in a reasonably large valence space outside the 164Pb core. Our calculations reproduce qualitatively the observed yrast spectra in 222–226Th up to spin 20+. The calculated results indicate that the non-axiality parameter decreases as one moves along the yrast states. The observed increase in deformation from 222Th to 226Th is due to the increase in the occupation of low-k components of $(2g_{9/2})_{\pi }$ and $(1j_{{15/2}})_{\nu }$ orbits. The model parameters reproduce not only the moment of inertia, deformation, and transition probabilities but also the proton and neutron pairing gaps and are the most appropriate for cranking studies in this region.

Air shower universality in the energy range of 1014 to 1022 eV

Universality in the development of air showers initiated by photons and the nuclei of cosmic rays is studied over a wide range of energies (1014–1022 eV). The scaling invariance of the lateral distribution of electrons and the universal relationship between a cascade’s age and radial scaling parameter (the root-meansquare radius of the electron component) are found to remain valid up to ultimate high energies with allowance for the Landau-Pomeranchuk-Migdal effect and interaction with the geomagnetic field. Possible applications of universality for matching, reanalyzing, and verifying the validity of data from different experiments, and for reducing the effect of the nuclear interaction model’s uncertainty on estimates of the mass composition of primary cosmic rays, are discussed.

Polymer Characterization by Static Laser Light Scattering

Low angle laser light scattering (LALLS) and multi-angle laser light scattering (MALLS) methods have become valuable, if not indispensable, tools for the chemist and biochemist, since they can be used to determine the absolute molecular weight and size of molecules in solution. When linked to a gel permeation chromatography system, they become even more powerful tools, providing information on molecular weight averages and their distributions (polydispersity). LALLS has essenttially been superseded by the development of on-line MALLS and size-exclusion chromatography (SEC)/MALLS systems, which have facilitated the greater application of light scattering theory in structure elucidation. For example, the determination of root mean square radii, molecular conformation and structure, branching ratios etc., are now readily achievable. This paper reviews the “theoretical backbone” of light scattering methods and the technology available for use in this particular aspect of macromolecular characterisation. Particular emphasis is placed on the use of SEC/MALLS and SEC/LALLS for the molecular weight elucidation of polysaccharides (such as carrageenans, starch, hyaluronic acid and dextrans), proteins, and the examination of branching in large macromolecular structures

Particulate structure of phytoglycogen nanoparticles probed using amyloglucosidase

Phytoglycogen is a plant-based, high-density carbohydrate nanoparticle that can be used as a starting material for preparing novel functional nano-constructs. In this study, the particulate structure of phytoglycogen was probed using amyloglucosidase hydrolysis, with amylopectin of waxy corn starch as a reference. Glucose release was monitored; molar mass, root mean square (RMS) radius, and dispersed molecular density were evaluated using multiangle laser-light scattering. The goal was to reveal the structural features of phytoglycogen nanoparticles. After extended amyloglucosidase hydrolysis, the total glucose release of phytoglycogen was lower than that of amylopectin. At the initial stage of hydrolysis, however, glucose was released at a higher rate from phytoglycogen, suggesting a dense distribution of nonreducing ends at the surfaces of nanoparticles. The reduction of molar mass and RMS radius caused by amyloglucosidase hydrolysis were much lower for phytoglycogen than for amylopectin. The dispersed molecular density of amylopectin remained at about 60 g/mol nm 3 during hydrolysis. In contrast, the density of phytoglycogen decreased from about 1200 to 950 g/mol nm 3, suggesting a density increment towards the external region of nanoparticle.

Radius studies of 8Li and 8B using the optical-limit Glauber model in conjunction with relativistic mean-field theory

We study the reaction cross sections (σR) and root-mean-square (RMS) radii of 8Li and 8B, the halo-like nuclei, with stable target 12C, 27Al and 9Be within the standard optical-limit Glauber model, using densities obtained from relativistic mean-field (RMF) formalisms and other types of distributions. It is found that the experimental σR can be reproduced well at high energy. The RMS radius and Δr extracted by RMF-theory and harmonic oscillator distribution are compared. We find that the RMS radius and Δr of 8B are larger than those of 8Li. In addition, we analyze in detail the relationship between σR and density distribution.