High-energy Dispersion Research Articles

Effect of magnetic field on the Bose–Einstein condensation of quantum well exciton–polaritons

We theoretically investigate the nonlinear effects of a magnetic field on the relaxation process of exciton–polaritons toward Bose–Einstein condensation in GaAs quantum wells. Our study reveals that the modification of the exciton’s effective mass, Rabi splitting, and dispersion significantly alters the relaxation rate of polaritons as they approach condensation. By employing a quasi-stationary pump, we clarify the dynamics of the total and condensed polariton populations in response to varying magnetic field strengths. Notably, we demonstrate that under low-energy pumping conditions, the presence of a magnetic field significantly suppresses condensation. This suppression is attributed to the decreased scattering rate between energy levels, which is a consequence of the reduced steepness in the high-energy dispersion. Conversely, increasing both the pump energy and the magnetic field can enhance relaxation efficiency, leading to a substantially larger number of condensed polaritons.

A Breathable and Strain‐Insensitive Multi‐Layered E‐Skin Patch for Digital Healthcare Wearables

AbstractIn this study, a breathable and strain‐insensitive multi‐layered electronic skin (e‐skin) capable of real‐time detection and distinction of electrocardiogram (ECG) signals, temperature, and skin hydration is developed. Leveraging a scalable benchtop method, sensing elements are transferred onto porous and hydrophobic substrates, followed by multi‐layer stacking to enable multimodal sensing. The sensing elements, a combination of carbon nanotube and nanoporous carbon (CNT@NPC) ink, are applied using strain‐insensitive patterned masks, then spray‐coated with styrene–ethylene–butylene–styrene (SEBS) to create a hierarchical porous network through phase separation. The CNT@NPC networks exhibit an improvement in strain insensitivity with active sensing capabilities due to their adaptable molecular tuning capacity and exceptional electrical conductivity. The porous SEBS substrate offers strong bonding with CNT@NPC attributed to the π–π interactions and high kinetic energy dispersion from spray coating allowing effective transfer. This unique design facilitates breathability, and miniaturization that minimizes the interference between different sensing modalities, ensuring accurate and reliable data acquisition. The breathability (3.49 mg cm−2 h−1) and the non‐smearing nature of the multi‐layered e‐skin enables simultaneous monitoring of temperature (0.198% °C−1), skin hydration (relative humidity = 0.77% %−1), and ECG (26 ± 1 dB) with continuous data transmission to a remote smartphone interface.

Body Armor-Inspired Double-Wrapped Binder with High Energy Dispersion for a Stable SiOx Anode.

The high specific capacity and relatively low volume expansion of silicon suboxide (SiOx) highlight its potential as one of the most promising anode materials for lithium-ion batteries. Nevertheless, the traditional binder of polyacrylic acid (PAA) still cannot adapt to enormous stress during the repeated volume expansion/contraction owing to its intrinsic rigid backbone. Inspired by the "soft and hard composite body armor", we herein design a double-wrapped binder consisting of PAA with a high internal Young's modulus (hard part) and polyurethane (DOU) with a low external Young's modulus (soft part). When the SiOx particle expands during lithiation, the rigid PAA firstly accommodates the volume change to dissipate most of the inner stress, and the elastic DOU with triple dynamic bonds serves as a buffer layer to absorb the residual stress via the breakage/formation of dynamic bonds. By optimizing the PAA/DOU ratio, the SiOx anode can maintain the integrity during long-term cycling and deliver a relatively high reversible capacity of 1064.1 mAh g-1 with a preeminent capacity retention of 83.7% at 0.5C after 300 cycles. Such a double-wrapped binder can provide a novel design strategy for multicomponent functional polymer binders toward high-performance SiOx anodes.

Transient simulation of the rapid guide vane adjustment under constant head of pump turbine in pump mode

In order to understand the flow mechanism of pump turbine during the rapid guide vane adjustment (RGVA), the shear stress transition (SST) k-ω turbulence model was used for transient simulation. The dynamic mesh technique was used to simulate the closing process of the guide vane. Combined with the verification of grid independence and the validation of experimental results, the variations of performance parameters (head, flow, torque), entropy production rate and pressure pulsation were calculated. And this process can be basically divided into three stages, including the preparation stage before the guide vane closing (Stage I), the guide vane closing stage (Stage II) and the completion stage of the guide vane closing (Stage III). The numerical simulation results showed that the performance parameters were varying in the form of exponential function during RGVA. The variation trend of the torque of each guide vane in the Stage II is basically the same, but the pulsation intensity in Stage III is different. In the Stage II, the guide vane is the component with the largest change in hydraulic loss, rising by about 362.5 %. The high energy dispersion sites are filling the flow passages of the guide vanes and the static vanes. The position with high pressure pulsation amplitude in the vaneless region also shifted, and the offset angle was 2–3°. The composition and evolution of the vortex structure in the vaneless region and the flow passage are determined by the Q-criterion. These structures, including horseshoe vortex and spanwise vortex, are the main reasons for the increase of pressure pulsation amplitude.

Encapsulation of bacteria in different stratified extracellular polymeric substances and its implications for performance enhancement and resource recovery

Simultaneous recovery of biopolymers and enhanced bio-reactor performance are promising options for sustainable wastewater treatment, and the bioactivity of sludge after biopolymer extraction is thus critical for the performance of the system. To this end, stratified extracellular polymeric substances (EPS), including slime, loosely bound EPS (LB-EPS), and tightly bound EPS (TB-EPS), were extracted, and the bioactivities of the consequent extraction residues were assessed using aerobic respirogram, kinetic, and flow cytometry (FCM). After the initial weak extraction of slime, the particle size distribution of the sludge significantly decreased, and subsequent extractions of LB-EPS and TB-EPS produced an equivalent size distribution. In contrast, the fractal dimension decreased after each extraction, suggesting that LB-EPS and TB-EPS affected the compactness of flocs rather than the size. The aerobic bacteria distribution estimated using respirogram shows that slime mainly encapsulated heterotrophs while LB-EPS mainly encapsulated nitrifiers. In addition, the ammonia-nitrogen affinity coefficient decreased from 1.79 to 0.28 mg/L when slime was removed, thereby encouraging the activities of autotrophic nitrifiers. Further removal of LB-EPS induced high energy dispersion as the maintenance coefficient m and the metabolic dispersion index μ/m increased from 0.11 to 0.22 and 0.44 to 0.63, respectively. Meanwhile, the yield rate decreased from 0.77 to 0.66. Although pellets that resulted from TB-EPS extraction were not aerobically active as described by respirogram and growth curves, they were still metabolically active as measured by live/dead cell counting and redox sensor green signal. These pellets used more energy for maintenance as indicated by the high maintenance coefficient than those residual after either slime or LB-EPS extraction. In addition, the variation in bacteria community distribution across flocs was related to the variation in temperatures, suggesting that the inner part of a floc might be hotter than the outer side. Therefore, compared to bacteria in the raw sludge, the viable bacteria bounded in LB-EPS and TB-EPS convert more energy to heat rather than growth. These results indicate that energy was dispersed as metabolic heat for the LB-EPS extracted sludge, and removal of LB-EPS favored thermogenesis and sludge reduction. Based on the above findings, a simultaneously EPS-recovery and performance enhancement configuration is thus proposed, which holds great promise for the integration of next-generation wastewater treatment plants.

The Properties of Cement Paste Incorporating Multi Wall Carbon Nanotube Solution Prepared through Bead Mill and High-Pressure Homogenizer Process with Polycarboxylate Ester

Carbon nanotube (CNT) has been successfully used for production of cementitious composites due to its excellent mechanical properties. In most of the existing literatures, the dispersion of CNT was mostly achieved using either ultrasonic water bath or tip sonicator that is known to provide relatively small amount of energy. In this work, the high energy dispersion processes, bead mill and high-pressure homogenizer, which have been applied for other industrial purposes, were applied to prepare multi wall carbon nanotube (MWCNT) solution with polycarboxylate ester (PCE) as a dispersing agent. The MWCNT solution was used for preparation of cement paste specimens. Ultrasonic tip sonication, a conventional lab-scale dispersion process, was also used for comparison purposes. According to the experimental results, PCE in MWCNT solution behaved as an air-entraining high-range water reducer for cement paste, causing increase in porosity, retardation in hydration, and reduction in undisturbed yield stress. Such effect was more significantly observed from the cases with bead mill and high-pressure homogenizer than ultrasonic tip sonication. The 28-day compressive strength increased by the addition of MWCNT, showing the maximum efficiency at 0.05% MWCNT content. The viscosity of cement paste increased as the amount of MWCNT increased, but flexural strength generally decreased as MWCNT was incorporated.

Laser ignition and combustion properties of composite with high-substituted nitrochitosan and nano-Ti powder

Although nano-Ti powder (n-Ti) exhibits a good application prospect in energetic materials, its agglomeration would weak the combustion efficiency and hinder its application as a combustion additive in solid propellants. Herein, the homogeneous binary composite nitrochitosan/nano-Ti (NCh/n-Ti) was prepared in acetone. The morphology structure, thermal behavior, laser ignition and impact sensitivity of NCh/n-Ti and nitrocellulose/nano-Ti (NC/n-Ti) were contrastively researched. The thermal decomposition temperature of NCh/n-Ti is lower than that of NC/n-Ti for the decomposition character of NCh, but NCh/n-Ti composites with the mass ratio of 1:3, 1:5 and 1:7 all exhibit higher flame propagation speed (48.5, 66.0 and 20.9 m s−1) than that of corresponding NC/n-Ti composites at the laser energy density of 130.7 W cm−2. And the ignition delay times for NCh/n-Ti composites are 8.5 (1:3), 5.3 (1:5) and 3.4 ms (1:7) respectively, which are all lower than that of the corresponding NC/n-Ti composites. Furthermore, the impact sensitivity of NCh/n-Ti is lower than that of corresponding NC/n-Ti. NCh/n-Ti presents better performances than NC/n-Ti. NCh can provide a new insight for high-energy dispersion medium instead of NC.

Cesium Rydberg-state ionization study by three-dimensional ion-electron correlation: Toward a monochromatic electron source

We study the excitation and ionization of cesium Rydberg states in an electric field ($\ensuremath{\approx}\phantom{\rule{0.16em}{0ex}}2200\phantom{\rule{4pt}{0ex}}\mathrm{V}/\mathrm{cm}$) near the classical field-ionization threshold ($\ensuremath{\approx}\ensuremath{-}280\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$ binding energy) by three-dimensional (3D) ion-electron coincidence spectroscopy. Cesium atoms are produced by an effusive oven and excited with lasers to Stark-shifted Rydberg states or directly ionized. Using a double time-of-flight setup we record 3D ($X, Y$, time of flight) coincidence imaging of electrons and ions. Above-threshold photoionization creates broad images with poor electron-ion spatial correlation. Fast ionizing states produce very good correlations and the images reveal the electric-field map of the ionization region. Slow ionizing states show that the relatively high atomic velocity is detrimental to the correlations. Experimental data are accurately reproduced by detailed Monte Carlo excitation and ionization simulations based on Stark maps obtained with local-frame transformation (LFT) theory. Agreement between our spectroscopic experiment and LFT theory is very good, with better that hundreds of megahertz accuracy. But, on rare particular states, several gigahertz discrepancy is found. This study can be used to select appropriate states for the creation of ion and electron beams with high brightness, good correlation, and low energy dispersion.

Nanoparticle characterization of HOMOEO AGROCARE (Agro Homeopathic Drug) by HRTEM and EDS analysis

Background: Use of Homeopathy as a therapeutic tool is still very nascent in plant science and agriculture. Therapies used for plant growth and diseases are not relevant for plants alone, but they also drastically influence the ecosystem of the organic world too. Use of pesticides and chemical fertilizers was a boon during the initial phase of green revolution around the world. Unfortunately, later they became the major reason of chronic illnesses like cancers and a cause for soil degradation all over. Current scenario demands the use of alternative models in agricultural practices in-order to prevent diseases and to maintain the health status of the population. This is also very important to get rid of the damages done to the soil. 
 Aims: Present study aimed at analyzing the material content of the agro homeopathic drug, ‘Homeo agrocare’. 
 Methdology: High resolution transmission electron microscope (HRTEM) and Energy dispersion spectroscopy (EDS) was used to evaluate the material content of the drug. 
 Results: (1) the drug solution contains plenty of nanoparticles (NPs). (2) the size of NPs ranges between 4.99nm - 120nm. (3) Twenty elements were identified in the fields studied. 
 Conclusion: Study conclusively proved the presence of NPs of the original drug materials used in the ‘Homoeo agrocare’ drug solution. The presence of NPs of the original drug substances suggest that the drug action of ‘Homoeo agrocare’ in plants is due to the epigenetic modifications initiated by the NPs in the plant genetics.

Foundations and trends of high resolution energy dispersive PIXE (HiRED-PIXE)

High Resolution Particle Induced X-ray Emission, for short HR-PIXE, dates back to 1977 and is, therefore, nearly as old as standard PIXE itself. Until roughly ten years ago, High Resolution PIXE (HR-PIXE) work used only wavelength dispersive spectrometers (WDS). The installation, in 2008, of an X-ray Microcalorimeter Spectrometer, XMS at CTN (ITN at the time) 3MV tandetron, altered this situation and, as can be recognised today, will lead to major changes in PIXE, and open up many possibilities that have been hindered so far. In this work, motives, developments, important breakthrough results obtained until now, and a case study displaying speciation data and complementary information from nuclear magnetic relaxometry, are presented and discussed, showing the full quantitative potential of High Resolution Energy Dispersion PIXE (HiRED-PIXE), in particularly the opening up of the possibility to establish fast and efficient methods for quantitative elemental speciation in unknown samples.

Au@CdO core/shell nanoparticles synthesized by pulsed laser ablation in Au precursor solution

Au@CdO core/shell nanocomposite was prepared using Pulsed Laser Ablation in Liquids (PLAL) via one step-process. A nanosecond pulsed laser (Nd:YAG, λ = 1064 nm) was used to ablate Cd sheet immersed in HAuCl4 solution. The surface plasmon resonance (SPR) using UV–vis absorption spectroscopy was employed to monitor the fast changes occurring in the NP colloidal solutions upon interaction between Cd sheets and Au precursor. The structure of the as-prepared samples was confirmed by high resolution transmission electron microscope (HRTEM) analysis and energy dispersion X-Ray spectroscopy (EDX) analysis. A mechanism for the growth of Au@CdO core/shell nanocomposite was given.

Catalytic reduction of 4-nitrophenol and photo inhibition of Pseudomonas aeruginosa using gold nanoparticles as photocatalyst

A simple, green method is described for the synthesis of Gold (Au) nanoparticles (NPs) using Cotoneaster horizontalis extract as a phyto-reducer and capping agent with superior photo inhibition activity against Pseudomonas aeruginosa. Different from the other methods used elevated temperatures for nanoparticles synthesis, the novelty of our method lies in its energy saving process and fast synthesis rates (~5min for AuNPs), and its potential to tune the nanoparticles size and afterward their catalytic activity. The starch, fatty acid and reducing sugars present in the extract are mostly responsible for repaid reduction rate Au+3 ions to AuNPs. Strong Plasmon resonance (SPR) of AuNPs was observed at 560nm, which indicates the formation of gold nanoparticles. Uv-visible spectroscopy, high resolution transmission electron microscope (HRTEM) and energy dispersion X-ray diffraction (XRD) were preformed to find out the formation of AuNPs. Proficient reduction of 4-nitrophenol (4-NP) into 4-aminophenol (4-AP) in the presence of AuNPs and NaBH4 was observed and was found to depend upon the nanoparticle size or the extract concentration. The AuNPs was also evaluated for antibacterial against P. aeruginosa. Before transferred it into antibacterial activity, it placed under visible light for 120min. The same experiment was performed in dark as control medium. The photo irradiated AuNPs was observed to be more effective against P. aeruginosa. The result showed that diameter of zone of inhibition of visible light irradiated AuNPs against P. aeruginosa was 17 (±0.5) and in dark was 8 (±0.4) mm.

Electron spectrometer for studying field-induced emission from nanostructured objects

A novel electron spectrometer has been designed to study low-voltage field-induced emission of nanostructures such as nanoporous carbon, nanotubes, nanodiamond and other carbon structures. The estimated high resolving power of the device is mainly achieved by using an original energy analyzer of high energy dispersion and by retarding the electron beam by the factor of tens and hundreds in terms of energy. The analyzer pass energy governs the absolute energy resolution ΔЕ of the spectrometer; ΔЕ value varies approximately in the range of 10meV<ΔЕ< 300meV. There are three different working modes adapted for emission of widely variable current. The minimal emission current at which energy analysis is still possible is approximately 0.1nA. The spectrometer working modes were tested experimentally using a thermoemitter as the test object. The study then proved that the recorded spectra reflected physical phenomena taking place on the emitter surface.

Origin of strong dispersion in Hubbard insulators

Using cluster perturbation theory, we explain the origin of the strongly dispersive feature found at high binding energy in the spectral function of the Hubbard model. By comparing the Hubbard and $t\small{-}J\small{-} 3s$ model spectra, we show that this dispersion does not originate from either coupling to spin fluctuations ($\propto\! J$) or the free hopping ($\propto\! t$). Instead, it should be attributed to a long-range, correlated hopping $\propto\! t^2/U$, which allows an effectively free motion of the hole within the same antiferromagnetic sublattice. This origin explains both the formation of the high energy anomaly in the single-particle spectrum and the sensitivity of the high binding energy dispersion to the next-nearest-neighbor hopping $t^\prime$.

Spectrum of the three-dimensional fuzzy well

We develop the formalism of quantum mechanics on three-dimensional fuzzy space and solve the Schrödinger equation for the free particle, finite and infinite fuzzy wells. We show that all results reduce to the appropriate commutative limits. A high energy cut-off is found for the free particle spectrum, which also results in the modification of the high energy dispersion relation. An ultra-violet/infra-red duality is manifest in the free particle spectrum. The finite well also has an upper bound on the possible energy eigenvalues. The phase shifts due to scattering around the finite fuzzy potential well are calculated.

Evaluation of Shirasu Porous Glass (SPG) membrane emulsification for the preparation of colloidal lipid drug carrier dispersions

Aqueous colloidal drug carrier dispersions based on nonpolar lipids are usually prepared by high energy dispersion techniques, like high-pressure homogenization. Homogenization generates high shear forces and may thus not be suitable for the processing of sensitive pharmaceutical ingredients, e.g., proteins. This study investigated the general possibility to prepare lipid nanoparticle dispersions by direct and premix Shirasu Porous Glass (SPG) membrane emulsification as alternative low energy and low shear method. The influence of different emulsifiers (polysorbate 20, sorbitan oleate, poloxamer 188, sodium dodecyl sulfate, sucrose laurate), the type of lipid phase (medium chain triglycerides, soybean oil, trimyristin, glyceryl behenate, lauroyl macrogolglycerides), the pore size of the SPG membrane (0.1, 0.2, 0.3, 0.5, 1.1μm) and the emulsifying pressure on the particle size of the resulting dispersions was investigated. The particle size was primarily controlled by the pore size of the membrane and the emulsifying pressure. Very narrow particle size distributions with membrane pore size/mean particle size ratios of 1:0.4–1:8.2 and 1:0.4–1:2.1 were observed for the direct and the premix membrane emulsification method, respectively. Due to the comparatively lower process pressures of at maximum 10bar SPG membrane emulsification is an interesting alternative method to high-pressure homogenization.

Transmission and application of electron spin wave function in alternating ferromagnetic and nonmagnetic layers

We establish a general model of a finite periodic system by n pairs of alternating ferromagnetic and nonmagnetic (FNF) layers. Using Bloch spin wave quantum theory, the basic properties of alternating FNF layers and the dependence of property of electron wave scattering in alternating layers on the number of layers are investigated. It is found that an electron wavefunction in the system can be expressed as the superposition of eigenvectors of a transfer matrix or Bloch-like functions in an infinite periodic system. Form this function we can obtain an exact solution for monochromatic wave scattering of a system with an arbitrary number of layers. On this basis, the dependences of reflection and transmission coefficients on energy for the electron wavefunction in a periodic system are determined. The calculation of spectral window shows that its energy position and width are the same as those of almost full reflection region. The system can be used as spin filter due to high-energy dispersion and dependence of exchange energy on electron spin direction.

Hard Metal Lung Disease Successfully Treated with Inhaled Corticosteroids

We herein report a case of hard metal lung disease that was successfully treated with inhaled corticosteroids. A 46-year-old man was admitted to our hospital due to coughing and an abnormal shadow on a chest radiograph. He had worked as a hard metal tool sharpener for five years. Chest computed tomography scans showed centrilobular micronodules and areas of ground-glass opacity in the bilateral lung fields. Video-associated lung biopsy specimens revealed bronchocentric interstitial pneumonia and cellular bronchiolitis. A high-energy dispersion X-ray microanalysis detected tungsten. The patient was diagnosed with hard metal lung disease. Inhaled corticosteroid therapy (800 μg of ciclesonide hydrofluoroalkane daily) resolved the patient's symptoms, elevated KL-6 level, abnormal areas of chest opacity and obstructive, restrictive and diffusion impairments.

Imaging the Formation of High-Energy Dispersion Anomalies in the ActinideUCoGa5

We use angle-resolved photoemission spectroscopy (ARPES) to image the emergence of substaintial dispersion anomalies in the electronic renormalization of the actinide compound UCoGa$_5$ which was presumed to belong to a conventional Fermi liquid family. Kinks or abrupt breaks in the slope of the quasiparticle dispersion are detected both at low ($\sim$130 meV) and high ($\sim$1 eV) binding energies below the Fermi energy, ruling out any significant contribution of phonons. We perform numerical calculations to demonstrate that the anomalies are adequately described by coupling between itinerant fermions and spin fluctuations arising from the particle-hole continuum of the spin-orbit split $5f$ states of uranium. These anomalies are resemble the `waterfall' phenomenon of the high-temperature copper-oxide superconductors, suggesting that spin fluctuations are a generic route toward multiform electronic phases in correlated materials as different as high-temperature superconductors and actinides.

Mechanochemical Approaches to Ceramic Ink Formulation for Digital Fabrication of Solid Oxide Fuel Cells

Four different ink processing protocols were investigated to control the particle size distribution of lab scale batches of inkjet inks used for printing Solid Oxide Fuel Cell (SOFC) anodes. The inks were composed of a mixture of commercial Nickel Oxide (NiO) and Yttria-stabilized Zirconia (YSZ) powders dispersed in organic solvents. Protocols incorporating high energy wet and dry milling using a SPEX 8000 mixer mill were compared to traditional low energy milling/dispersion methods. Brunauer-Emmett-Teller (B.E.T.) surface area measurements were used in conjunction with scanning electron microscopy (S.E.M.) to determine the effects of the milling protocols on the dry powder particle sizes and morphologies. Dynamic light scattering (D.L.S.) was used to measure the particle size distributions of the inks. Low energy dispersion of the NiO and YSZ powders produced an ink with a number weighted particle size distribution peaked &#x223C; 300 nm and a significant tail of particles as large as 1 &#x3BC;m. Adding high energy dry milling or high energy slurry dispersion to the process removed most of the large particle size tail, but the particle size distribution remained peaked at 250 &#x2013; 300 nm. By combining high energy dry powder milling with high energy slurry dispersion, the main peak in the particle size distribution shifted to 180 nm with minimal particles above 600 nm. These results indicate that the combination of high energy milling and dispersion enable lab scale production of nanoscale NiO/YSZ inks from commercial powders. The protocols developed in this work provide a first step towards the goal of controlling the microstructure of inkjet printed solid oxide fuel cell (SOFC) anodes through control of the ink particle size distribution.