A Wave Nature-Based Interpretation of The Nonclassical Feature of Photon Bunching On A Beam Splitter

Born’s rule is key to understanding quantum mechanics based on the probability amplitude for the measurement process of a physical quantity. Based on a typical particle nature of a photon, the quantum feature of photon bunching on a beam splitter between two output photons can be explained by Born’s rule even without clear definition of the relative phase between two input photons. Unlike conventional understanding on this matter, known as the Hong-Ou-Mandel effect, here, we present a new interpretation based on the wave nature of a photon, where the quantum feature of photon bunching is explained through phase basis superposition of the beam splitter. A Mach-Zehnder interferometer is additionally presented to support the correctness of the presented method. As a result, our limited understanding of the quantum feature is deepened via phase basis superposition regarding the destructive quantum interference. Thus, the so-called ‘mysterious’ quantum feature is now clarified by both the definite phase relationship between paired photons and a new term of the phase basis superposition of an optical system.

Particle motion and erosion morphology of the spool orifice in an electro-hydraulic servo valve under a small opening

To explore the spool orifice’s particle motion and erosion morphology in an electro-hydraulic servo valve under a small opening, a modeled particle motion visualization test and CFD calculation were conducted to study typical particle trajectory. The influence of pressure differential, particle shape, and particle diameter on the erosion rate along the working edges was discussed. The erosion characteristic morphology and working edges’ fillet diameter distribution were measured and analyzed. There are four typical particle motions: translation and spin on the wall faced the flow, translation and turn on the backflow wall, carried motion by the mainstream and particle rotation in a vortex. A model of the erosive particle motion of the spool orifice was built based on the visualization test and CFD. During these motions, the microscopic scraping and collision of particles with the working edges are the main causes of erosion wear. The erosion wear rate of the working edge is proportional to the pressure differential and the non-roundness of the particles. The fillet of a working edge periodically increases or decreases with the circumferential angle, which occurs due to the morphology and is consistent with the erosion wear rate distribution along the working edge.

Discrete Element Method Simulations of Additively Manufactured Components With Integrated Particle Dampers

One major benefit of Additive Manufacturing is parts counts reduction. Several formerly distinct parts can be printed as one unit, reducing cost and weight. However, the interface between parts is often a major source of vibration damping, so eliminating interfaces can lead to fatigue failures. To alleviate this, researchers have been exploring the integration of damping features inside parts. Leaving a small pocket of unfused powder creates a particle damper. Particle dampers have long been known to suppress unwanted vibration. However they are highly complex and predicting their behavior is difficult. The particle damper literature often has contradictory claims, as what works best for one application does not work for another. Because the additive feedstock powder is much smaller (5–50 μm) than particles in typical particle dampers, it is difficult to draw conclusions from the existing literature to develop design guidelines. This papers reports on a Discrete Element Method (DEM) numerical simulation of additively manufactured cantilever beams with a small pocket of unfused powder. DEM explicitly simulates the motion of each particle and their interactions. Previously reported experiments with varying beam geometry showed nearly an order of magnitude difference in damping ratio depending on the location of the pocket along the beam. The simulation was able to accurately predict the damping ratio based on the input geometry. As a result, the correlated simulation tool can be used to optimize future designs. From the simulations, it was observed that particle-wall momentum exchange and particle-particle inelastic collisions appeared to be key contributors to the damping ratio. Additionally, a non-linear subharmonic motion of particles was observed, which suggests additional ways to improve performance.

The Particle Radiobiology of Multipotent Mesenchymal Stromal Cells: A Key to Mitigating Radiation-Induced Tissue Toxicities in Cancer Treatment and Beyond?

Mesenchymal stromal cells (MSCs) comprise a heterogeneous population of multipotent stromal cells that have gained attention for the treatment of irradiation-induced normal tissue toxicities due to their regenerative abilities. As the vast majority of studies focused on the effects of MSCs for photon irradiation-induced toxicities, little is known about the regenerative abilities of MSCs for particle irradiation-induced tissue damage or the effects of particle irradiation on the stem cell characteristics of MSCs themselves. MSC-based therapies may help treat particle irradiation-related tissue lesions in the context of cancer radiotherapy. As the number of clinical proton therapy centers is increasing, there is a need to decidedly investigate MSC-based treatments for particle irradiation-induced sequelae. Furthermore, therapies with MSCs or MSC-derived exosomes may also become a useful tool for manned space exploration or after radiation accidents and nuclear terrorism. However, such treatments require an in-depth knowledge about the effects of particle radiation on MSCs and the effects of MSCs on particle radiation-injured tissues. Here, the existing body of evidence regarding the particle radiobiology of MSCs as well as regarding MSC-based treatments for some typical particle irradiation-induced toxicities is presented and critically discussed.

MICROPARTICLE SEPARATION IN A LINEAR PAUL TRAP

We investigated the charged micron-sized particle separation by the alternating electric field in a linear quadrupole electrodynamic trap in open air under standard atmospheric temperature and pressure conditions (STP). In experiments we varied the amplitude of the alternating voltage supplying the electrodynamic trap and used a mixture of charged glassy carbon and alumina particles. The carried out numerical simulations and experimental results showed the mutual influence of the amplitude and frequency of the supplied to the trap electrode voltage on the separation of the different sizes particles. The typical particle charges in simulations were approximately equal to experimentally measured values obtained in a corona discharge.

Experimental investigation of angle dependent torque properties of a particle rotary damper using a magnetic elastomer particle assemblage

Typical particle rotary dampers generate constant torque throughout the cycle of rotation. However, this research is focused on generating angle dependent torque i.e. different torque at different angles. The damper is designed to generate an elevated torque at a specific angle. This can be achieved by employing ferromagnetic particles and by introducing a permanent magnet in the damper. This study is carried out using two major parameters I) base torque which is the measure of damping capacity and II) percentage increase in torque which is the measure of angle dependency. From the experimental investigations, it has been found that I) base torque increases with packing fraction and rotational speed and decreases conditionally with the amount of carbonyl iron present in the particle while II) percentage increase in torque decreases with packing fraction, remains constant with rotational speed and increases conditionally with the amount of carbonyl iron present in the particle.

Synthesis of the ZnTiO3/TiO2 Nanocomposite Supported in Ecuadorian Clays for the Adsorption and Photocatalytic Removal of Methylene Blue Dye

Currently, the study of semiconductor materials is very promising for the photocatalytic remediation of hazardous organic substances present in the air and water. Various semiconductors have been investigated in this interesting photo-assisted methodology, among them metal oxides such as ZnO, TiO2 and their derivatives. In this study, ZnTiO3/TiO2 was synthesized by the sol-gel method using Ti(OC3H7)4 and Zn(CH3COO)2 · 2H2O as reagents. The role of several conditions such as synthesis temperature and TiO2:ZnO proportion on the morphology and purity of compounds obtained was studied, and the suitable conditions for the synthesis of photocatalysts were determined. Various techniques were used to conduct a systematic investigation on the structural, morphological, and photocatalytic properties of ZnTiO3/TiO2. Scanning Electron Microscopy (SEM) images show that ZnTiO3/TiO2 have a typical particle size of approximately 100 nm with a quasi-spherical shape. The adsorption and photocatalytic activity were investigated by the decolorization of Methylene Blue (MB) as an organic contaminant under UV irradiation both in TiO2 and ZnTiO3/TiO2 supported over some Ecuadorian clays. The materials evaluated were prepared in the shape of 0.2 cm (diameter) and 1.0 cm (length) cylindrical extrudates. The degradation percentage of MB obtained was 85% approximately after 150 min of irradiation. The results obtained allow us to conclude that these synthesized materials can be used as adsorbents and photocatalysts.

Is the near-spherical shape the new black for smoke?

We examine the capability of near-spherical-shaped particles to reproduce the non-typical Particle Linear Depolarization Ratio (PLDR) values measured over Europe for stratospheric smoke originating from Canadian wildfires. The smoke layers were detected both in the troposphere and the stratosphere, though in the latter case the particles presented PLDR values of almost 18 % at 532 nm as well as a strong spectral dependence from the UV to the Near-IR. The assumption that the smoke particles have a near-spherical shape allows for the reproduction of the observed PLDR and Lidar Ratio (LR), whereas this was not possible when using more complicated shapes. The results presented here are supported by recent findings in the literature, showing that up to now the near-spherical shape (or closely similar shapes) is the only morphology found capable of reproducing the observed intensive optical properties of stratospheric smoke, as well as their spectral dependence.