Construction status and prospects of the Hyper-Kamiokande project

The Hyper-Kamiokande project is a 258-kton Water Cherenkov together with a 1.3-MW high-intensity neutrino beam from the Japan Proton Accelerator Research Complex (J-PARC). The inner detector with 186-kton fiducial volume is viewed by 20-inch photomultiplier tubes (PMTs) and multi-PMT modules, and thereby provides state-of-the-art of Cherenkov ring reconstruction with thresholds in the range of few MeVs. The project is expected to lead to precision neutrino oscillation studies, especially neutrino CP violation, nucleon decay searches, and low energy neutrino astronomy. In 2020, the project was officially approved and construction of the far detector was started at Kamioka. In 2021, the excavation of the access tunnel and initial mass production of the newly developed 20-inch PMTs was also started. In this paper, we present a basic overview of the project and the latest updates on the construction status of the project, which is expected to commence operation in 2027

Prospects for neutrino astrophysics with Hyper-Kamiokande

Hyper-Kamiokande is a multi-purpose next generation neutrino experiment. The detector is a two-layered cylindrical shape ultra-pure water tank, with its height of 64 m and diameter of 71 m. The inner detector will be surrounded by tens of thousands of twenty-inch photosensors and multi-PMT modules to detect water Cherenkov radiation due to the charged particles and provide our fiducial volume of 188 kt. This detection technique is established by Kamiokande and Super-Kamiokande. As the successor of these experiments, Hyper-K will be located deep underground, 600 m below Mt. Tochibora at Kamioka in Japan to reduce cosmic-ray backgrounds. Besides our physics program with accelerator neutrino, atmospheric neutrino and proton decay, neutrino astrophysics is an important research topic for Hyper-K. With its fruitful physics research programs, Hyper-K will play a critical role in the next neutrino physics frontier. It will also provide important information via astrophysical neutrino measurements, i.e., solar neutrino, supernova burst neutrinos and supernova relic neutrino. Here, we will discuss the physics potential of Hyper-K neutrino astrophysics

LINK QUALITY, DELAY AND ENERGY AWARE ROUTING PROTOCOL (LQDEARP) FOR MOBILE AD HOC NETWORKS

Routing Optimization in mobile ad hoc networks is an ever-demanding task. Mobile ad hoc networks are highly dynamic topology natured and hence several routing protocols meet the challenge of link quality, delay and energy conscious routing. This paper proposes a link quality, delay and energy conscious routing approach based on ant colony optimization. Based on the estimated link quality, delay and residual energy of the nearby nodes, Adaptive node stability (ANS) mechanism is mathematically modeled to make the routing strategy. LQDEARP selects the efficient node based on the ANS mechanism and sends the data packets through that node. Simulation results proved that LQDEARP reduces delay and energy consumption and increases packet delivery ratio than that of the AODV and DECRP protocol

Optimization of energy and fluence of N2+ ions in the conversion of Al2O3 surface into AlN at room temperature

The work presents a systematic study of energetic N2+ ion interaction with the clean Al2O3 surface at room temperature. Energetic N2+ ions with energies ranging from 0.1 to 5 keV were bombarded onto the c-plane Al2O3 surface in situ in a UHV system equipped with X-ray Photoelectron Spectroscopy. Survey scans and core level spectra of Al(2p), O(1s), N(1s) were recorded as a function of ion fluence. Survey scans of XPS are used for the compositional analysis, while deconvoluted core level spectra are used to identify the evolution of the chemical bonding. Energetic dependence of N2+ ions occupying interstitial and substitutional sites in Al2O3 lattice are probed to follow the surface evolution. Results show that maximum thickness of surface is nitride by 5 keV N2+ ion with an optimal fluence of 1.5 × 1015 ions/cm2. This modified surface can be used as a template for low defect III-nitrides growth, with enhanced lattice matching than on bare c-Al2O3

Optimization of energy and fluence of N2+ ions in the conversion of Al2O3 surface into AlN at room temperature

The work presents a systematic study of energetic N2+ ion interaction with the clean Al2O3 surface at room temperature. Energetic N2+ ions with energies ranging from 0.1 to 5 keV were bombarded onto the c-plane Al2O3 surface in situ in a UHV system equipped with X-ray Photoelectron Spectroscopy. Survey scans and core level spectra of Al(2p), O(1s), N(1s) were recorded as a function of ion fluence. Survey scans of XPS are used for the compositional analysis, while deconvoluted core level spectra are used to identify the evolution of the chemical bonding. Energetic dependence of N2+ ions occupying interstitial and substitutional sites in Al2O3 lattice are probed to follow the surface evolution. Results show that maximum thickness of surface is nitride by 5 keV N2+ ion with an optimal fluence of 1.5 × 1015 ions/cm2. This modified surface can be used as a template for low defect III-nitrides growth, with enhanced lattice matching than on bare c-Al2O3

Preparation and characterization of oxides of Ni-Cu: Anode material for methanol oxidative fuel cells

Oxides of Ni-Cu were electrodeposited and characterized by SEM, IR and XPS techniques. These studies indicate that the coatings are mostly amorphous, made up of tiny particles of copper metal or a very low alloy with nickel in non-metallic phases with non-stoichiometric compositions. The deposited oxide films exhibit low overvoltages at 303 K for methanol oxidation and act as effective anode materials. Electrocatalytic activity of the deposited films depends on the composition of the coating. Under working conditions the deposits exhibit good corrosion resistance towards the electrolyte medium

Characterization of Ni-Pd alloy as anode for methanol oxidative fuel cell

Electrochemical deposition of Ni-Pd alloy films of various compositions from bath solution containing ethylenediamine (EDA) was carried out to use as anode material for methanol oxidative fuel cell in H2SO4 medium. Electronic absorption spectrum of bath solution containing Ni2+, Pd2+ ions and EDA indicated the formation of a four coordinate square planar metal-ligand complex of both the metal ions. X-ray diffraction (XRD) patterns of the deposited alloy films show an increase in Pd-Ni alloy lattice parameter with increase in Pd content, and indicate the substitution of Pd in the lattice. A nano/ultrafine kind of crystal growth was observed in the alloy film deposited at low current density (2.5 mA cm-2). X-ray photoelectron spectroscopic (XPS) studies on the successively sputtered films showed the presence of Ni and Pd in pure metallic states and the surface concentration ratio of Ni to Pd is less than bulk indicating the segregation of Pd on the surface. Electro-catalytic oxidation of methanol in H2SO4 medium is found to be promoted on Ni-Pd electrodeposits. The anodic peak current characteristics to oxidation reaction on Ni-Pd was found typically high when compared to pure nickel and the relative increase in surface area by alloying the Ni by Pd was found to be as much as 300 times. © 2003 Elsevier Science B.V. All rights reserved

Mechanisms of action and in vivo antibacterial efficacy assessment of five novel hybrid peptides derived from Indolicidin and Ranalexin against Streptococcus pneumoniae

Background. Antimicrobial peptides (AMPs) are of great potential as novel antibiotics for the treatment of broad spectrum of pathogenic microorganisms including resistant bacteria. In this study, the mechanisms of action and the therapeutic efficacy of the hybrid peptides were examined. Methods. TEM, SEM and ATP efflux assay were used to evaluate the effect of hybrid peptides on the integrity of the pneumococcal cell wall/membrane. DNA retardation assay was assessed to measure the impact of hybrid peptides on the migration of genomic DNA through the agarose gel. In vitro synergistic effect was checked using the chequerboard assay. ICR male mice were used to evaluate the in vivo toxicity and antibacterial activity of the hybrid peptides in a standalone form and in combination with ceftriaxone. Results. The results obtained from TEM and SEM indicated that the hybrid pep- tides caused significant morphological alterations in Streptococcus pneumoniae and disrupting the integrity of the cell wall/membrane. The rapid release of ATP from pneumococcal cells after one hour of incubation proposing that the antibacterial action for the hybrid peptides is based on membrane permeabilization and damage. The DNA retardation assay revealed that at 62.5 μg/ml all the hybrid peptides were capable of binding and preventing the pneumococcal genomic DNA from migrating through the agarose gel. In vitro synergy was observed when pneumococcal cells treated with combinations of hybrid peptides with each other and with conventional drugs erythromycin and ceftriaxone. The in vivo therapeutic efficacy results revealed that the hybrid peptide RN7-IN8 at 20 mg/kg could improve the survival rate of pneumococcal bacteremia infected mice, as 50% of the infected mice survived up to seven days post- infection. In vivo antibacterial efficacy of the hybrid peptide RN7-IN8 was signficantly improved when combined with the standard antibiotic ceftriaxone at (20 mg/kg + 20 mg/kg) as 100% of the infected mice survived up to seven days post-infection. Discussion. Our results suggest that attacking and breaching the cell wall/membrane is most probably the principal mechanism for the hybrid peptides. In addition, the hybrid peptides could possess another mechanism of action by inhibiting intracellular functions such as DNA synthesis. AMPs could play a great role in combating antibiotic resistance as they can reduce the therapeutic concentrations of standard drugs