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In this paper, we present a coupling of homotopy perturbation technique and sumudu transform known as homotopy perturbation sumudu transform method (HPSTM). We show applicability of this method by solving fractional equal width (EW) equation, fractional modified equal width (MEW) equation and variant of fractional modified equal width (VMEW) equation. The fractional equal width equations play a key role in describing hydro-magnetic waves in cold plasma. Our aim is to study the nonlinear behavior of plasma system and highlight the important points. We examine the ability of HPSTM to study the fractional nonlinear systems and show its supremacy over other available numerical techniques. The other key point of this investigation is to examine two important fractional equations with different nonlinearity. The HPSTM gives excellent accuracy in analogous with the numerical solution. The numerical solutions indicate that the HPSTM is a powerful technique for studying the nonlinear behavior of plasma system very precisely and accurately.

Two-dimensional (2D) molybdenum disulfide (MoS2)–based materials are of great interest because of their capacity to efficiently absorb electromagnetic spectrum in the visible region. Starting from the structural and electronic properties, this review discusses the synthesis strategies of 2D MoS2. The major photocatalytic applications of 2D MoS2 such as hydrogen evolution, pollutant degradation, self-cleaning, photoelectrochemical water splitting, and microbial disinfection are summarized. The mechanistic understanding of various photocatalytic applications of 2D MoS2 is summarized through schematic diagrams. In addition, this review outlines the methodologies for improving the 2D MoS2 photocatalysts and recapitulates the research directions in this area of semiconductor photocatalysis.

Condensation is of paramount importance in numerous technological applications where phase change processes take place. The physical nature of condensation from vapor to liquid can impose limits on the speed of the process, especially at the interface of the vapor, surface, and liquid. However, the nature of the surfaces themselves, especially those with low wettability, have been shown to enhance and promote condensation. This review is focused on the advances in surface wettability related to enhancement of condensation processes and while both filmwise and dropwise modes are addressed, emphasis is given to the enhancement of drop-wise condensation which produces higher heat transfer. Fundamental theoretical models governing surface wetting characteristics and heat transfer in condensation are presented. Methods to reduce wetting including coatings of low surface energy materials such as polymers, noble metals, rare-earth oxides, organic monolayers, switchable wettability surfaces, and ion-implantation are discussed. Certain surface features along with low surface energy coatings can enable droplet removal at much smaller sizes and can even control the droplet movements during condensation. Special emphasis is given to characteristics of these surface features including roughness, porous structures, hybrid surfaces, micro-grooved surfaces, and lubricant infused surfaces. Additionally, challenges and opportunities associated with the use of these surfaces in condensation are discussed. It is noted that dropwise condensation is prone to surface flooding at higher subcoolings. Moreover, the surface design is critical to choice of working fluid and further developments are required to achieve dropwise condensation of working fluids of low surface tension. The current review focusses on recent technological advances that may assist with the development of dropwise condensation for industrial, domestic and consumer related heat transfer devices, along with the concomitant superior heat transfer capabilities over the filmwise mode.

Cardiovascular events are an important group of critical incidents in anaesthesia. They include hypotension, hypertension, myocardial ischaemia/infarction, arrhythmias and cardiac arrest. These incidents require prompt recognition to stabilise the patient.

Analyzing powers and differential cross sections for the inelastic scattering of 15 MeV polarized protons to the stronger collective states of 58, 60 Ni and 64 Zn have been measured. The data were compared to detailed microscopic reaction calculations using a central plus spin-dependent effective interaction. The nuclear structure wave functions used were obtained from a quasiparticle random-phase appoximation calculation using a spin-dependent surface delta interaction and a basis set containing both neutron and proton configurations. The overall quality of the fits strongly suggests that the surface-delta wave functions provide a good representation for spherical nuclei in this intermediate mass range. The effects of exchange and further modifications to the microscopic effective interaction are discussed.

Liquid metal magnetohydrodynamic (LMMHD) generators use two-phase flow, for example, of an organic vapor through mercury, for Rankine cycle operation. Unfortunately, the efficiencies achieved in such generators have been reported to suffer from inhomogeneity of the flow and even instability for very high void fraction. We suggest the use of the magnetic fluid concept—single domain iron particles suspended in the metallic carrier liquid making it a “magnetic” liquid, so to speak—to improve the stability of the flow. Through standard stability analysis, we will show that a magnetic field placed parallel to the flow indeed improves greatly the range of void fractions for stable flow. Universality and scaling properties of the results are also discussed.

The problem of coupling an odd nucleon to the collective states of an even core is considered in the intermediate-coupling limit. It is now well known that such intermediate-coupling calculations in spherical open-shell nuclei necessitate the inclusion of ground-state correlation or backward coupling which gives rise to an overcomplete basic set of states for the diagonalization of the hamiltonian. In a recent letter 1 ), we have derived a technique to free the single-particle equation-of-motion method of redundancy. Here we shall apply this redundancy-free equation-of-motion method to intermediate-coupling calculations in two regions of near-spherical odd-mass nuclei where forward coupling alone has not been successful. It is shown that qualitative effects of backward coupling previously reported are not spurious effects of double counting, although they are significantly modified by the removal of redundancy. We also discuss what further modifications of the theory will be needed in order to treat the dynamical interplay of collective and single-particle modes in nuclei self-consistently on the same footing.

The surface-delta interaction (SDI) of Moszkowski is applied to calculations of quadrupole vibrational states of spherical nuclei with the following special features: (i) The spin-dependence of the force is treated correctly. This is important for doubly open-shell nuclei, (ii) The phase of the single-particle wave functions at the surface is taken into account. This is important for the calculation of the E2 transition probability from the one-phonon state to the ground state. Numerical calculations are presented for the NiZn region and the TeBaXe region. The results are compared with the predictions of the pairing-plus-quadrupole model and with experiment. The agreement with experiment is very good.

A method is developed for the calculation of non-normal parity vibration and single-particle strength functions for nuclei with one nucleon outside a doubly closed shell. The coupled linearized equations for the amplitudes of excitation of the states of the odd-mass nucleus are obtained by considering the equation of motion of the odd nucleon. This is accomplished by employing an expansion in terms of a complete set of states of the closed-shell core, yielding a hermitian matrix. The states of the core are treated by the hole-particle-RPA method. Numerical calculations are presented for 17 O. It is found that no single phonon-coupled or single-particle state occurs below 5 MeV.

The low-lying states of an odd-mass spherical nucleus are considered to be states of a quasi-particle coupled to an even core. The quasi-particle modes are obtained by the Bogolyubov-Valatin transformation. The coupled linearized equations for the amplitudes of excitation of the states of the odd-mass nucleus are obtained by the equation-of-motion method. The problem is formulated so that only amplitudes of single excitations appear, as this automatically ensures hermiticity, in contrast to the second random phase approximation. This is accomplished by employing an expansion in terms of a complete set of states of the even core. The states of the core are treated by RPA. This method is called extended quasi-particle-phonon coupling (EQPC) as it can be regarded as an extension of the usual quasi-particle-phonon coupling (QPC) through the inclusion of the “backward-going” amplitudes. Preliminary numerical calculations, based on the pairing plus quadrupole force effective Hamiltonian, show that the effects of “backward-coupling” are very pronounced in the odd-mass isotopes of Tc, Rh and Ag. This mechanism seems to provide an explanation for the occurrence of low-lying phonon levels in these nuclei. The self-consistency of the theory is also discussed.

The bootstrap theory of vibrations is developed for closed-shell nuclei where the particle and phonon modes of these nuclei are generated simultaneously and self-consistently. It is shown that in first order the phonon solutions of this theory correspond to the random-phase approximation (RPA). The properties of the particle modes is also studied in this order. It is found that particle (hole) states are pushed up in energy which can account for the discrepancy between the shell-model particle-hole energies and the experimental ones. The non-normal parity states (particle-phonon coupled mode) are also studied and it is found that some of these can be expected to lie close in energy to the normal parity (particle mode) states, as it is experimentally found. The possibility of a different approach where the calculation of even- and odd-mass nuclei is carried out separately, the extended-particle-phonon-coupling theory (EPPC without bootstrap) is also pointed out. A numerical example using the perturbation theoretical solution of EPPC theory is given for 39, 40, 41Ca.

Following a suggestion of Pal, a canonical quasiparticle transformation is derived by the linearization method of Anderson, Valatin and Pal for the case of nuclei in which neutron and proton simultaneously fill the oscillator shells. The proposed method treats the J = 0 part (i.e. the short-range part) of the neutron-proton interaction on the same footing as the J = 0 part of n-n and p-p interaction, The energy gap is shown to arise from the J = 0 part of n-n, p-p and n-p force. Since each angular momentum state can now be occupied both by neutron and proton, the quasiparticles introduced in this method are linear combinations of proton hole and particle and neutron hole and particle. Such a transformation does not conserve the z component Tz of isobaric spin, but since this is given by 1 2 (neutron number N-proton number Z), violation of this conservation law is on the same footing as that of violation of particle number conservation. For N = Z nuclei, the method does not apply as such. However, a quasi-particle transfomation based on the strict isobaric-spin conservation in this case is proposed which can possibly account for the energy gap of these nuclei.

The spin-, isospin- and spin-isospin quadrupole modes in spherical open shell nuclei are studied through a modified surface delta interaction model.

The excitation energies and γ-ray decay modes of several low-lying states in the nucleus 73Ge have been studied using Coulomb excitation with 2.6–4.0 MeV α-particles on an enriched 73Ge target to test the predictions of quasiparticle-phonon coupling theories, in particular to test if there are any high-spin states in the low-energy spectrum. Gamma-rays were observed with a 60 cm3 Ge(Li) detector. Thick-target γ-ray yields were utilized to establish Coulomb excited levels, to clarify the γ-ray decay of 73Ge, and to obtain reduced upward transition probabilities, B(E2)↑, associated with the levels indicated as follows: 68.6 keV (0.073 ±0.007), 499.0 keV (0.0091±0.0005) and 825.6 keV (0.077±0.004). Angular distributions of the de-excitation γ-rays from the Coulomb excited levels were measured and various spin possibilities for each level were eliminated by the χ2 technique. The following spinparity assignments are consistent with our γ-ray angular distribution measurements: 68.6 keV ( 5 2 + , 7 2 + , 9 2 + ), 499.0 keV ( 7 2 + ), and 825.6 ( 7 2 + , 13 2 + ). Branching ratios were extracted from the γ-ray angular distribution measurements. The eB(E2)↑ values for the first 2+ excited states of 72Ge(0.18), 74Ge(0.29), and 76Ge(0.27) were also obtained. The results for 73Ge are compared with the predictions of several quasiparticle-phonon coupling theories and some suggestions are made to improve agreement between experiment and theory.

In a previous paper we have developed a self-consistent (bootstrap) theory of vibrations which is particularly suited for the description of the anharmonicity of the even nuclear spectra. In this paper we combine the bootstrap idea with the group theoretical approach. We show that this theory enables us to understand the smooth transition from vibrational to rotational spectrum and in particular the quasirotational spectrum which is the intermediate situation. Applications of this theory is made for the quadrupole-quadrupole and the pairing Hamiltonians. The observation is made that the smooth transition from vibrational to rotational spectrum for both cases is very similar.

The hexadecapole-collective motion in spherical nuclei is discussed. Numerical calculations are presented and compared with available experimental data.

A derivation of the pairing and generalized pairing theories for nuclei is given based on a self-consistent orthonormalization procedure within the context of the equation of motion method.