Communications in Physics

According to experimental data of SNe Ia (Supernovae type Ia), we will discuss in detial dynamics of the DGP model and introduce a simple parametrization of matter $\omega$, in order to analyze scenarios of the expanding universe and the evolution of the scale factor. We find that the dimensionless matter density parameter at the present epoch $\Omega^0_m=0.3$, the age of the universe $t_0= 12.48$ Gyr, $\frac{a}{a_0}=-2.4e^{\frac{-t}{25.56}}+2.45$. The next we study the linear growth of matter perturbations, and we assume a definition of the growth rate, $f \equiv \frac{dln\delta}{dlna}$. As many authors for many years, we have been using a good approximation to the growth rate $f \approx \Omega^{\gamma(z)}_m$, we also find that the best fit of the growth index, $\gamma(z)\approx 0.687 - \frac{40.67}{1 + e^{1.7. (4.48 + z)}}$, or $\gamma(z)= 0.667 + 0.033z$ when $z\ll1$. We also compare the age of the universe and the growth index with other models and experimental data. We can see that the DGP model describes the cosmic acceleration as well as other models that usually refers to dark energy and Cold Dark Matter (CDM).

The folding model analysis of the elastic $\alpha + \alpha$ scattering at the incident energies below the reaction threshold of 34.7 MeV (in the lab system) has been done using the well-tested density dependent versions of the M3Y interaction and realistic choices for the $^4$He density. Because the absorption is negligible at the energies below the reaction threshold, we were able to probe the $\alpha + \alpha$ optical potential at low energies quite unambiguously and found that the $\alpha + \alpha$ overlap density used to construct the density dependence of the M3Y interaction is strongly distorted by the Pauli blocking. This result gives possible explanation of a long-standing inconsistency of the double-folding model in its study of the elastic $\alpha + \alpha$ and $\alpha$-nucleus scattering at low energies using the same realistic density dependent M3Y interaction.

The recent BaBar measurements of the $\gamma\gamma^{*}\to \pi^{0}$ form factor show spectacular deviation from perturbative QCD computations for large space-like $Q^{2}$. At $34\,\rm GeV^{2}$ the data are more than 50% larger than theoretical predictions. Stimulated by these new experimental results, we revisit our previous paper on triangle loop effects related to chiral anomaly, and apply our method to the $\gamma + \gamma^* \to \pi^0$ form factor measured in the single tag mode $e^{+} + e^{-}\to e^{+} + e^{-} + \pi^{0}$ with one highly virtual photon. The resultant form factor $F(Q^{2})$ - which depends on only one parameter (the mass $m$ of up, down quark circulating in the triangle loop) behaves like $(\frac{m^{2}}{Q^{2}})\times (\ln(Q^{2}/m^{2}))^{2}$ - shows a striking agreement with BaBar data for $m \approx 132\,\rm MeV$. The rising logarithm squared form factor, surprisingly unnoticed in the literature, is in sharp contrast with the rather flat ones derived from perturbative QCD approaches.

This paper is a brief review of low energy soft hadronic physics, starting from the invention of the low energy effective range theory in the late 40's due to Bethe and Schwinger for nucleon-nucleon scattering, and its generalization to the static Chew-Low model for pion nucleon scattering, to the present development of the Lehmann and Weinberg Chiral Perturbation Theories. It is pointed out that a consistent low energy calculation can be achieved with the incorporation of the unitarity relation in the Chiral Perturbation Theory. Comment: 30 pages, 3 figures. To be publised in the proceeding of International Conference on flavor physics (2009), Hanoi

The standard model has postulated the existence of a scalar boson, named the Higgs boson. This boson plays a central role in a symmetry breaking scheme called the Brout-Englert-Higgs mechanism (or the Brout-Englert-Higgs-Guralnik-Hagen-Kibble mechanism, for completeness) making the standard model realistic. However, until recently at least, the 50-year-long-sought Higgs boson had remained the only particle in the standard model not yet discovered experimentally. It is the last but very important missing ingredient of the standard model. Therefore, searching for the Higgs boson is a crucial task and an important mission of particle physics. For this purpose, many theoretical works have been done and different experiments have been organized. It may be said in particular that to search for the Higgs boson has been one of the ultimate goals of building and running the LHC, the world's largest and most powerful particle accelerator, at CERN, which is a great combination of science and technology. Recently, in the summer of 2012, ATLAS and CMS, the two biggest and general-purpose LHC collaborations, announced the discovery of a new boson with a mass around 125 GeV. Since then, for over two years, ATLAS, CMS and other collaborations have carried out intensive investigations on the newly discovered boson to confirm that this new boson is really the Higgs boson (of the standard model). It is a triumph of science and technology and international cooperation. Here, we will review the main results of these investigations following a brief introduction to the Higgs boson within the theoretical framework of the standard model and Brout-Englert-Higgs mechanism as well as a theoretical and experimental background of its search. This paper may attract interest of not only particle physicists but also a broader audience.

The first three coefficients of the Taylor's series expansion of the vector pion form factor as a function of the momentum transfer are evaluated using experimental data on the pion form factor and the P-wave pi pi phase shifts. The real part of the form factor as a function of energy is also calculated by dispersion relation. Comparisons these results with Chiral Perturbation Theory and unitarized models are given.

Starting with the generalized electromagnetic field equations of dyons, we have discussed the theory of magnetohydrodynamics (MHD) of plasma for particles carrying simultaneously the electric and magnetic charges (namely dyons). It is shown that the resultant system supports the electromagnetic duality of dyons. Consequently the frequency of dyonic plasma has been obtained and it is emphasized that there is a different plasma frequency for each species depending on wave number k. For k to be real, only those generalized electromagnetic waves are allowed to pass, for which the usual frequency is greater than the plasma frequency (i.e. \omega>\omega_{p}). It is shown that the plasma frequency sets the lower cuts for the frequencies of electromagnetic radiation that can pass through a plasma . Accordingly the ohm's law has been reestablished to derive the plasma oscillation equation as well as the magetohydrodynamic wave equation and the energy of dyons in unique and consistent manner. Comment: PACS NO: 14.80.Hv (Magnetic Monopoles), 52.30.Cv (Magnetohydrodynamics -including electron magnetohydrodynamics) Keywords: Magnetohydrodynamics, dyons, electromagnetic fields.

The topological Lifshitz phase transition is studied systematically within an effective model of QCD, in which the chiral symmetry, broken at zero temperature, is not restored at high temperature and/or baryon chemical potential. It is found that during phase transition the quark system undergoes a first-order transition from low density fully-gapped state to high density state with Fermi sphere which is protected by momentum-space topology. The Lifshitz phase diagram in the plane of temperature and baryon chemical potential is established. The critical behaviors of various equations of state are determined.

It is explicitly shown that either the approximate solution of the integral equation for the inverse of the pion form factor, or the result of the Pad\'e approximant method of resumming the one loop Chiral Perturbation Theory (CPTH) are equivalent to the standard vector meson dominance (VMD) models, using the vector meson coupling to two pseudoscalars given by the KSRF relation. Inconsistencies between the one loop CPTH and its unitarised version (or the VMD model) are pointed out. The situation is better for the CPTH calculation of the scalar form factor and the related S-wave $\pi \pi$ scattering. The branching ratios of $\tau \to \pi^+ \pi^0 \nu$, $\tau \to K \pi \nu$, $\tau \to K^+ \eta \nu$ and $\tau \to K^+ \bar{K^0} \nu$ using only two inputs as the $\rho $ and $K^*$ masses, or the two corresponding rms radii, agree with the experimental data. Using the same number of parameters, the corresponding one loop CPTH calculation cannot explain the $\tau$ data.

A new supersymmetry is proposed for hadrons containing a single heavy quark. This supersymmetry is based on a new approximation to those hadrons, which we would consider as a further step beyond the spectator light diquark model of baryons. The heavy diquark effective theory is constructed by the techniques introduced in a different context by Georgi and Wise$^1$ and by Carone$^2$. This theory can be incorporated into a supersymmetric theory together with Heavy Quark Effective Theory, and leads to a common universal Isgur-Wise function for mesons and baryons./.

Superluminal electromagnetic fields of dyons are described in T^{4}- space and Quaternion formulation of various quantum equations is derived. It is shown that on passing from subluminal to superluminal realm via quaternion the theory of dyons becomes the Tachyonic dyons. Corresponding field Equations of Tachyonic dyons are derived in consistent, compact and simpler form. Abstract Key words- Monopoles, Dyons, Tachyons, Quaternions, Superluminal and Electromagnetic fields. Abstract PACS Nos- 03.50 De, 14.80 Hv.

This work is devoted for gauge boson sector of the recently proposed model based on SU(3)_C X SU(3)_L X U(1)_X group with minimal content of leptons and Higgses. The limits on the masses of the bilepton gauge bosons and on the mixing angle among the neutral ones are deduced. Using the Fritzsch anzats on quark mixing, we show that the third family of quarks should be different from the first two. We obtain a lower bound on mass of the new heavy neutral gauge boson as 6.051 TeV. Using data on branching decay rates of the $Z$ boson, we can fix the limit to the Z and Z^prime mixing angle phi as $-0.001\le\phi\le 0.0003$.

With the advantages of selectivity, spectral resolution and reduction of interference on account of light scattering, synchronous luminescence spectroscopy (SLS) is successfully applied to analyze complex mixtures with overlapped emission and/or excitation spectra. In fact, it is difficult to clearly distinguish the contributions of various luminescence centers to low-energy band of semiconductor nanocrystals (NCs). Herein, we report the application of SLS method to detect luminescence centers in colloidal Cd_0.3Zn_0.7S NCs. Their conventional luminescence and synchronous luminescence spectra were comparatively investigated. Differently from conventional luminescence spectrum, the emission peaks at 460 and 515 nm were found using SLS method. They are attributed to the emission transitions related to sulfur and zinc/cadmium vacancies. The obtained results are useful to clarify the nature of luminescence centers as well as relaxation mechanism in Cd_xZn_1-xS NCs.

Orthorhombic Na0.44MnO2 with an S-shape tunnel structure was successfully synthesized by a hydrothermal method. The Na0.44MnO2 material has lattice parameters of a = 9.0842 Å, b = 26.2889 Å, and c = 2.8245 Å. Scanning electron microscope analysis reveals that the morphologies of Na0.44MnO2 consist of Na0.44MnO2 nanowires with diameters of about 30-50 nm and Na0.44MnO2 particles with the size in the range of 200 to 500 nm. The first charge and discharge capacities of Na0.44MnO2 cathode, at 0.1 C between 2.0-4.0 V, are 66.2 mAh g-1 and 62.7 mAh g-1, respectively. The Na0.44MnO2 has an excellent cycle stability with 85.3% of capacity retention over 50 cycles. The coulombic efficiency of Na0.44MnO2 material is approximately 90% after 70 cycles. It is suggested that the structure of Na0.44MnO2 is stable during cycling and Na0.44MnO2 can be a promising cathode material for sodium ion batteries.

Lead-free ferroelectric materials have attracted considerable attention due to the increasing potential application in environmental benign materials. Among lead-free ferroelectric materials, the Bi 0.5 Na 0.5 TiO 3 (BNT) materials were more studied because it exhibited the good ferroelectric and piezoelectric properties which could be promising candidate materials replacing Pb(Zr,Ti)O 3 . In this work, the lead-free ferroelectric BNT materials were synthesized by sol-gel method. The effects of fabrication process to microstructural and optical properties were studied which includes Na precursor concentration and calcining temperature. The result indicated that the Na precursor concentration were higher 40 mol.% and the calcining temperatures

In this paper, we report results on the fabrication and magnetic properties of spinel ferrite Mn1-xZnxFe2O4 (0 ≤ x ≤ 0.8) nanoparticles. The nanoparticles were synthesized by a co-precipitation method. The effects of substituting Zn for Mn on the magnetic properties and particles size were focused. It was found that the phase-formation temperature is 90OC and the average particle size decreases from 40 nm to 10 nm when increased Zn concentration from zero to 0.8. The Curie temperature TC strongly decreases from 585 K (x = 0) to 320 K (x = 0.8) concomitantly with a decrease of the saturation magnetization MS. With a TC of 320 K and MS of 17 emu/g, the x=0.8 sample could be a promising candidate for some biomedical applications.

We report on successful growth of epitaxial and high Curie-temperature Ge 1-xMn x quantum dots on Si (001) substrates using the auto-assembled approach. By reducing the growth temperature down to 400 °C, we show that the Mn diffusion into the Si substrate can be neglected. No indication of secondary phases or clusters was observed. Ge 1-xMn x quantum dots were found to be epitaxial and perfectly coherent to the Si substrate. We also observe ferromagnetic ordering in quantum dots at a temperature higher 320 K. It is believed that single-crystalline quantum dots exhibiting a high Curie temperature are potential candidates for spin injection at temperatures higher than room temperature.

By mean of molecular beam epitaxy (MBE) equipped with a reflexion high-energy electron diffraction (RHEED) technique, we have chosen an intermediate and appropriate substrate temperature of 130\(\r{}\)C to reproducibly synthetize high-T\(_{C}\) Ge\(_{1 - x}\)Mn\(_{x}\) nanocolumns phase. Laser Pulse Atom Probe Tomography (LP-APT) technique have been used to determine at atomic scale the chemical composition inside nanocolumns and also in the surrounding diluted matrix. The Mn concentration inside nanocolumns is found to be highly inhomogeneous, it is about 20\({\%}\) at the bottom and can increase up to \(\sim 40{\%}\) in the top near the surface region. The Mn concentration in the matrix is about 0.25\({\%}\) at the surface and can reach a highest value of $\sim $1{\%} in regions close to the interface.

Stopping powers of \(\alpha\)-particles emitted by \(^{148}\)Gd, \(^{241}\)Am and \(^{243}\)Cm isotopes in PR10 and isobutane\break (C\(_{4}\)H\(_{10}\)+Ar) gases have been experimentally measured in the energy region from 1.0 to 5.5 MeV. The experimental data were compared with those calculated by SRIM-2013 computer code. It was concluded that the experimental stopping powers in our investigated region are in agreement with the calculated values.

In this paper, the dependences of the velocities and the absorption coefficients of ultrasonic waves transmitted in 1018 low carbon steel on temperature ranging from 0\(^{\circ}\)C to 50\(^{\circ}\)C were investigated. It was shown that the velocities of the ultrasonic longitudinal wave and ultrasonic shear wave were decreased when the temperature increased. The transportation of the ultrasonic longitudinal wave and ultrasonic shear wave depends on temperature and its coefficient in a temperature range of (0 - 50 \(^{\circ}\)C) was estimated about 0.8 m/s.\(^{\circ}\)C and 0.44~m/s.\(^{\circ}\)C, respectively. These obtained results are in good agreement with the theoretical prediction. Furthermore, the absorption coefficients of the ultrasonic longitudinal wave were also studied.

Detail characterization of the such laser diode is important for the applications. Electro-Optical and spectral characteristics of the high power 1064 nm DFB-MOPA lasers are investigated at room temperature as function of injection current. Beam quality is characterized by waist diameter and far-field divergence angle versus average optical output power. Beam propagation ratio M2 is defined at difference intensity levels from lateral beam profile giving more detail laser behaviors at high power.

We investigate the impact of ambiguities coming from the choice of optical potentials and nucleon-nucleon scattering cross sections on the spectroscopic factors extracted from the 12C(p,2p)11B reaction. These ambiguities are evaluated by analyzing the cross sections of the 12C(p,2p)11B reaction at 100 and 200 MeV within the framework of the distorted-wave impulse approximation with realistic choices of nuclear inputs. The results show that the studied ambiguities are considerably large in this energy region and careful choices of nuclear inputs used in the reaction calculations are required to extract reliable structure information.

Nuclear reactions of proton by light nuclei at low energies play a key role in the study of nucleosynthesis which is of interest in nuclear astrophysics. The most fundamental process which is very necessary is the elastic scattering. In this work, we construct a microscopic proton-nucleus potential in order to describe the differential cross-sections over scattering angles of the proton elastic scattering by 12C and 13C in the range of available energies 14 - 22 MeV. The microscopic optical potential is based on the folding model using the effective nucleon-nucleon interaction CDM3Yn. The results show the promising use of the CDM3Yn interactions at low and very low energies, which were originally used for nuclear reactions at intermediate energies. This could be the premise for the study of nuclear reactions using CDM3Yn interaction in astrophysics at low energies.

The yield ratio of the high-spin state of \(^{122m}\text{Sb} (8^{ - })\) and the low-spin state of \(^{122g}\text{Sb} (2^{-})\) formed via the \(^{123}\text{Sb}(\gamma, n)^{122m,g}\text{Sb}\) reaction has been measured as a function of the bremsstrahlung end-point energy in the range of 40-MeV to 60-MeV. Use was made of the activation technique in combination with high-resolution \(\gamma\)-ray spectrometry. The isomeric yield ratios for the \(^{123}\text{Sb}(\gamma,n)^{122m,g}\text{Sb}\) reaction measured at 40-, 45-, 50-, 55-, and 60-MeV bremsstrahlung are \(0.341\pm 0.022\), \(0.362 \pm 0.020\), \(0.374 \pm 0.021\), \(0.371 \pm 0.021\), and \( 0.367 \pm 0.022\). According to our knowledge, the present results are the first measurement.

The elastic scattering cross section measured at energies $E\lesssim 10$ MeV/nucleon for some light heavy-ion systems having two identical cores like \oc exhibits an enhanced oscillatory pattern at the backward angles. Such a pattern is known to be due to the transfer of the valence nucleon or cluster between the two identical cores. In particular, the elastic $\alpha$ transfer has been shown to originate directly from the core-exchange symmetry in the elastic \oc scattering. Given the strong transition strength of the $2^+_1$ state of $^{12}$C and its large overlap with the $^{16}$O ground state, it is natural to expect a similar $\alpha$ transfer process (or inelastic $\alpha$ transfer) to take place in the inelastic \oc scattering. The present work provides a realistic coupled channel description of the $\alpha$ transfer in the inelastic \oc scattering at low energies. Based on the results of the 4 coupled reaction-channels calculation, we show a significant contribution of the $\alpha$ transfer to the inelastic \oc scattering cross section at the backward angles. These results suggest that the explicit coupling to the $\alpha$ transfer channels is crucial in the studies of the elastic and inelastic scattering of a nucleus-nucleus system with the core-exchange symmetry.\Keywords{optical potential, coupled reaction channels, inelastic $\alpha$ transfer

We present a study of the polarization observables of the $W$ and $Z$ bosons in the process \(p p \to W^\pm Z\to e^\pm \nu_e \mu^+\mu^-\) at the 13 TeV Large Hadron Collider. The calculation is performed at next-to-leading order, including the full QCD corrections as well as the electroweak corrections, the latter being calculated in the double-pole approximation. The results are presented in the helicity coordinate system adopted by ATLAS and for different inclusive cuts on the di-muon invariant mass. We define left-right charge asymmetries related to the polarization fractions between the \(W^+ Z\) and \(W^- Z\) channels and we find that these asymmetries are large and sensitive to higher-order effects. Similar findings are also presented for charge asymmetries related to a P-even angular coefficient.

In this work we present the results of measurement of the isomeric ratio of fission fragment e in photofission of 237Np induced by bremsstrahlung in the Giant Dipole Resonance Region by the method using the inert gaseous flow. The experiments have been performed at the electron accelerator Microtron MT-25 of the Flerov laboratory of Nuclear Reaction, Joint Institute for Nuclear Research, Dubna, Russia. The results were discussed and compared with that of other authors.

In this work we present the results of measurement of the isomeric ratio of fission fragment e in photofission of 237Np induced by bremsstrahlung in the Giant Dipole Resonance Region by the method using the inert gaseous flow. The experiments have been performed at the electron accelerator Microtron MT-25 of the Flerov laboratory of Nuclear Reaction, Joint Institute for Nuclear Research, Dubna, Russia. The results were discussed and compared with that of other authors.

In this work, the correlation between 137Cs and 40K concentration in tea tree and soil in Luong My farm, Tan Thanh district, Luong Son commune, Hoa Binh province was experimentally investigated. The measurements were carried out using gamma spectroscopy with high purity germanium detector HPGe. The results showed that 40K is uniformly distributed in the soil depth while 137Cs is mainly located in 10 cm of the soil surface. Soil-plant transfer factor (TF) for 40K varies in the range of 0.491 to 0.623 and that of 137Cs is in range of 0.384 to 0.510. The concentration of these two radionuclides in tree parts is opposite to each other, while 40K is concentrated in the leave, 137Cs is mainly found in the root.

Nd\(_2\)Fe\(_{14}\)B/Fe\(_{65}\)Co\(_{35}\) hard magnetic ribbons were fabricated by melt-spinning technique using Nd\(_{16}\)Fe\(_{76}\)B\(_{8 }\) and Fe\(_{65}\)Co\(_{35}\) pre-alloys as starting materials. The results showed that the formation of the interactive hard/soft nanocomposite with the homogeneous distribution of the Fe-Co phase throughout the Nd\(_{2}\)Fe\(_{14}\)B matrix provided the Curie temperature (\(T_{c})\) as high as 747 K, the magnetic remanence (B\(_{r}\)) of 8.88 kG and the maximum energy product, (BH)\(_{\max}\), of 16.75 MG.Oe for the fabricated Nd\(_{2}\)Fe\(_{14}\)B/Fe\(_{65}\)Co\(_{35}\) ribbons at the optimal speed of 25 m/s. In addition, the intrinsic coercivity (\(_{i}\)H\(_{c}\)) of 9.27 kOe and remanence coercivity (\(_{b}\)H\(_{c}\)) of 6.94 kOe were found for these ribbons. The roles of the soft Fe\(_{65}\)Co\(_{35}\) phase in the increasing of \(T_{c}\), \(B_{r}\) as well as in the (00l) preferred crystallographic orientation of hard magnetic grains on the free surface side of the fabricated ribbons were also discussed.

The elastic scattering cross section measured at energies \(E\lesssim 10\) MeV/nucleon for some light heavy-ion systems having two identical cores like \(^{16}\)O+\(^{12}\)C exhibits an enhanced oscillatory pattern at the backward angles. Such a pattern is known to be due to the transfer of the valence nucleon or cluster between the two identical cores. In particular, the elastic \(\alpha\) transfer has been shown to originate directly from the core-exchange symmetry in the elastic \(^{16}\)O+\(^{12}\)C scattering. Given the strong transition strength of the $2^+_1$ state of $^{12}$C and its large overlap with the $^{16}$O ground state, it is natural to expect a similar \(\alpha\) transfer process (or inelastic \(\alpha\) transfer) to take place in the inelastic \(^{16}\)O+\(^{12}\)C scattering. The present work provides a realistic coupled channel description of the \(\alpha\) transfer in the inelastic \(^{16}\)O+\(^{12}\)C scattering at low energies. Based on the results of the 4 coupled reaction-channels calculation, we show a significant contribution of the \(\alpha\) transfer to the inelastic \(^{16}\)O+\(^{12}\)C scattering cross section at the backward angles. These results suggest that the explicit coupling to the \(\alpha\) transfer channels is crucial in the studies of the elastic and inelastic scattering of a nucleus-nucleus system with the core-exchange symmetry.

This work presents the updated heat capacities of \(^{161-164}\)Dy nuclei in the nuclear temperature region from 0 to 1 MeV. The updated heat capacities are obtained within the canonical ensemble method making use of the most recent and recommended experimental nuclear level density (NLD) data together with those calculated within the back-shifted Fermi gas (BSFG) model with energy-dependent parameters. By comparing the updated heat capacities with the un-updated ones, which are obtained by using the old experimental NLD data and the BSFG with energy-independent parameters, we found that the updated and un-updated heat capacities are almost identical at low temperature, but differ from each others at high temperature. This discrepancy can be interpreted by the damping of nuclear shell structure with increasing the excitation energy. Besides, we observe that the S-shape in the updated heat capacities is much more pronounced in even-even Dy isotopes than in even-odd ones, whereas the un-updated heat capacities do not clearly exhibit this S-shape. Therefore, the updated heat capacities should provide a more convincing evidence for the signature of pairing phase transition in nuclear systems.

In this work we present the yield ratios of the \(^{179m,g}\)W isomeric pair produced in the photonuclear reactions \(^{nat}\)W(g,xn)\(^{179m,g}\)W with bremsstrahlung end-point energies of 50-, 55-, 60-, and 65-MeV. The measurements were carried out by the induced activity method in combination with direct gamma-ray spectrometry. The measured activities were corrected for overlapping gamma-ray peaks, self-absorption of low energy gamma-rays and true coincidence summing effects. The present results are measured for the first time with bremsstrahlung end-point energies beyond the giant dipole resonance region. The obtained results are discussed with respect to the incident bremsstrahlung energies and reaction channel effect.

The yield ratios of high to low spin states of the 196m,gAu, 186m,gIr, and 183m,gOs isomeric pairs produced by 197Au(γ,xnyp) reactions with a bremsstrahlung end-point energy of 2.5 GeV have been measured. Measurements were performed by the activation method in combination with off-line γ-ray spectrometry. The induced activity of the studied radionuclides was derived from the photo-peak area of the selected γ-ray after making the necessary corrections. The isomeric yield ratios obtained in this work are the first measurement. The relationships between the yield ratios of studied isomeric pairs with the value of high spin states, the spin difference between the high spin states and the target nucleus, and the number of nucleons emitted from the target nucleus are discussed.

We present a simple model to calculate multiplicities of the neutrons emitted in the interaction of a proton beam energy from 0.5 GeV to 1.5 GeV on some targets such as 82 206 Pb, 79 197 Au, 92 238 U using database of JENDL-HE library. The results are compared with the available experimental data [8]. The agreement is satisfactory.

Two series of SrFe\(_{12}\)O\(_{19}\)/NiFe\(_{2}\)O\(_{4}\) nanocomposite ferrites sintered in air at 850\rc{}C and 950\rc{}C were prepared using SrFe$_{12}$O$_{19}$ and NiFe\(_{2}\)O\(_{4}\) nanopowders obtained via sol-gel method. The phase composition, surface morphology and magnetic properties of the composites were investigated using XRD, SEM and VSM respectively. For the SrFe$_{12}$O$_{19}$/NiFe$_{2}$O$_{4}$ ferrites with volume ratio ranging from 61 to 21 and sintered in 850\(\r{}\)C for 5 hours in air, all the specimens are composed of two phases but exhibit a typical single-phase magnetic behavior, indicating the existence of exchange coupling (EC) between the magnetically hard and soft phases. The value of coercivity H\(_{c}\) decreases from 6.19 kOe to 0.574 kOe when volume of SrFe$_{12}$O$_{19}$ decreases from 6 to 1. While the samples with a mass ratio of \(R_{m}\)= SrFe\(_{12}\)O\(_{19}\)/ NiFe\(_{2}\)O\(_{4}\) varying from 31 to 13 sintered in 950\rc{}C for 5 hours characterized with a ``bee waist'' type hysteresis loop. These results reveal that the magnetically hard and soft magnetic phases are not exchange- coupled. The saturation magnetization (\(M_{S}\)) increases from 36 emu/g to 43.3 emu/g when \(R_{m}\) decreases from 31 to 13 and then decreases with \(R_{m}= 12\) and 13.

Seven photo-neutron reactions 197Au(γ,xn)197-xAu (with x=1-7) produced by the bremsstrahlung end-point energy of 60 MeV were identified. In this work, we focus on the measurement of integrated sections. Experiments were carried out based on the activation method in combination with off-line gamma-ray spectrometric technique. The integrated cross sections of the investigated reactions were determined relative to that of the monitoring reaction 197Au(γ,n)196Au. To validate the experimental results, theoretical predictions were also made using the computer code TALYS 1.9. The current integrated cross-sections of the 197Au(γ,xn)197-xAu reactions with 60 MeV bremsstrahlung end point energy are measured for the first time.

We identified eight radionuclides \(^{196}\)Au, \(^{195}\)Au, \(^{194}\)Au, \(^{193}\)Au, \(^{192}\)Au, \(^{191}\)Au, \(^{190}\)Au, \(^{189}\)Au formed via the multiple photoneutron reactions \(^{197}\)Au\((\gamma ,kn)^{197 - k}\)Au with 2.5 GeV\break bremsstrahlung. The yields of radionuclides that decay by emitting \(\gamma \)-ray were measured using high purity germanium (HPGe) detector coupled to a PC-based multichannel analyzer. In order to improve the accuracy of the experimental results the necessary corrections were made. The obtained results are compared with reference data and the variations of the \(^{197}\)Au(\(\gamma \),kn)\(^{197 - k}\)Au reaction yields according to incident bremsstrahlung energy and neutron multiplicity are also discussed.

We present the fabrication, simulation, and measurements of 1D photonic crystal based on nano-porous silicon multilayer designed as an optical interference filter. Using electro-chemical etching with timely repeat steps of applied current densities, we fabricated a multilayer structure composed of alternating high- and low-index layer which achieved 90% power reflectivity at wavelength range of 1400-3000 nm. The simulation is relying on the Transfer Matrix Method (TMM) to design and predict the optical properties of nano-porous silicon multilayer as well as the relation between anodization parameters with reflection spectra. The measured reflection and transmission spectra of the nano-porous silicon multilayer show good agreement with simulation. This technique could provide a convenient and economical method to produce filters, cavities, and graded-index dielectric waveguides in the future.

The stellar reaction 22Mg(α,p)25Al plays an important role for understanding the nucleosynthesis of stars. It has never investigated yet. We are planning to study this reaction in environment of X-rays burst with temperature T9 = 1÷3 GK using invert kinematics and thick target method. This paper shows a design for direct investigation of this reaction by simulation method. This design is necessary for experimental setup and for confirmation of the feasibility of the experiment.

The cross-sections for the formation of \(^{89}\)Nb and \(^{90}\)Nb radionuclides in proton induced nuclear reactions on zirconium were measured by using the well known activation method. The natural zirconium (\(^{nat}\)Zr) target and copper (\(^{nat}\)Cu) monitor foils were irradiated by 27.7 MeV proton beam at the MC50 Cyclotron of the Korea Institute of Radiological and Medical Science (KIRAMS), Korea. The induced gamma activities of the reaction products were measured by a coaxial high purity germanium (HPGe) detector coupled to a PC-based multichannel analyzer. The obtained cross sections for each nuclide are compared with those existing in literature and with the theoretical cross sections calculated by the TALYS - 1.4 code.

The photonuclear reactions of (γ, xn) or (γ, xnp) types can be used to produce high-intensity neutron sources for research and applied purposes. In this work a Monte-Carlo calculation has been used to evaluate the production yield of neutrons from the (γ, n) and (γ, 2n) reactions following the bremsstrahlung produced by a 100 MeV electron beam on a tungsten target.

Under the assumption that isospin \(T\) is a good quantum number, mirror transitions \(T_{z }= +1 \to 0\) and \(T_{z }= -1 \to 0\) were studied in \(A = 34\) isobars, where \(T_{z}\) is \(z\) component of iospin \(T\) and is defined by \(T_{z} = (N-Z)/2\). With a high energy resolution of 35 keV in \(^{34}\)S\((^{3}He,t)^{34}\)Cl reaction measurement at \(0^{\circ}\) scattering angle and at an incident energy of 140 MeV/nucleon, strengths of Fermi and Gamow-Teller (GT) transitions from the \(J^{\pi } = 0^{ + }\), \(T_{z }= +1\) ground state of \(^{34}\)S to the \(J^{\pi } = 1^{+ }\), \(T_{z }= 0\) excited states in \(^{34}\)Cl were determined up to excitation energy \((E_{x})\) of \(7.08\) MeV. The corresponding isospin-symmetric transitions connecting \(T_{z }= -1\) and \(T_{z }= 0\) states can be studied in the \(^{34}\)Ar \(\beta ^{ + }\) decay. The strengths of the \((GT)_{\pm }\) transitions were compared up to the excitation energy of 3.1 MeV. A good agreement was observed for two strong transitions to \(2.580\) MeV and \(3.129\) MeV states, while a disagreement about \(45\text{%}\) was observed for a weaker transition to \(0.666\) MeV low-lying state.

The relative intensities of prompt g-rays from the ³⁵Cl(n, g)³⁶Cl reation with thermal neutron have been used as secondary g-ray intensity standards for the prompt gamma neutron activation analysis (PGNAA) and for nuclear data measurements due to a high capture cross section. The filter neutron technique was applied for producing a thermal neutron beam at the neutron channel No. 4 of the Dalat nuclear research reactor. The neutron flux and Cd-ratio are 8.72 ´ 10⁶ n.cm⁻².s⁻¹and 134, respectively, determined by the gold foil activation method. A new PGNAA system with a HPGe detector of 58% relative efficiency and a digital spectrometer was used to detect prompt gamma rays from the ³⁵Cl(n, g)³⁶Cl reaction. In this work, relative intensities of 23 prompt g-rays have been determined on the filtered thermal neutron beam. The present results within accuracy 3.0% or better are in good agreement with literature values and data from previous measurements.

The Amyloid beta (Aβ) oligomers are characterized as critical cytotoxic materials in Alzheimer’s disease (AD) pathogenesis. Structural details of transmembrane oligomers are inevitably necessary to design/search potential inhibitor due to treat AD. However, the experimental detections for structural modify of low-order Aβ oligomers are precluded due to the extremely dynamic fluctuation of the oligomers. In this project, the transmembrane Italian-mutant (E22K) 3Aβ11-40 (tmE22K 3Aβ11-40) was extensively investigated upon the temperature replica exchange molecular dynamics (REMD) simulations. The structural changes of the trimer when replacing the negative charged residue E22 by a positively charged residue K were monitored over simulation intervals. The oligomer size was turned to be larger and the increase of β-content was recorded. The momentous gain of intermolecular contacts with DPPC molecules implies that tmE22K 3Aβ11-40 easier self-inserts into the membrane than the WT one. Furthermore, the tighter interaction between constituting monomers was indicated implying that the E22K mutation probably enhances the Aβ fibril formation. The results are in good agreement with experiments that E22K amyloid is self-aggregate faster than the WT form. Details information of tmE22K trimer structure and kinetics probably yield the understanding of AD mechanism.

The 3C-SiC nanorods were grown by using carbothermal reduction of SiO\(_{2}\) without any catalyst. The intensive broad photoluminescence peak around 480-500 nm was observed at room temperature. The 3C-SiC nanorods with green -- blue emitting light may have great application in display devices and light emitting diodes.

Graphene/polymer composite thin film electrodes have many important applications, but the fabrication of these electrodes is often difficult because of poor processability of graphene. This paper presents the primary results on using 3D printing technique for thin film electrode preparation from graphene-based composite ink. The printing ink was synthesized from graphene oxide (GO), polyvinyl alcohol (PVA) as a binder and stabilizer, and ascorbic acid (AA) as a reducing agent. The measured zeta potential value showed that PVA can make GO ink more stable, the absolute value of zeta potential increased from 10.1 mV (without PVA) to 31.4 mV (with 12 wt. % PVA). The thin film electrodes can be easily printed using GO/PVA/AA composite ink, and obtained voltammograms recorded on the surface of these electrodes in 5 mM K3[Fe(CN)6]/K4[Fe(CN)6] solution clearly indicated the GO reduction by AA. The best electrochemical properties of printed electrodes were founded in the case of composite ink with wt/wt ratio GO:PVA:AA = 80:12:8. The cyclic voltammetric results demonstrated the linear dependence of the anodic and cathodic signals of redox couple [Fe(CN)6]4-/K3[Fe(CN)6]3- with the square root of scan rate, indicating a reversible redox reaction on the electrode surface. The thin films printed from GO/PVA/AA composite ink can be used as electrode material for diverse applications in electrochemistry.

The Charged Hard Sphere (CHS) reference system is applied to study the structural analysis of liquid 3d transition metals. Here we report the structure factor S(q), pair distribution function g (r), interatomic distance r1 of nearest neighbour atoms and coordination number n$_1$ for liquid 3d transition metals viz: Ti, V, Cr, Mn, Fe, Co, Ni and Cu. To describe electron–ion interaction our own model potential is employed alongwith the local field correction due to Sarkar et al (SS). The present results of S(q) and g (r) are in good agreement with experimental findings. The maximum discrepancy obtained from the experimental data for the coordination number is 4.22% in the case of Ti while the lowest is 0.31% for Cu. Thus CHS is capable of explaining the structural information of a nearly empty d-shell, nearly filled d-shell and fully filled d-shell elements.