Strong Condensation Research Articles

GOTHIC and MELCOR benchmarking of the CNL strong condensation containment apparatus experiments

Understanding severe accident behaviour in water-cooled small modular reactors is crucial for their deployment, as well as having qualified software tools for safety analysis. A model benchmarking exercise was conducted where predictions from the software tools GOTHIC and MELCOR were compared against past experiments from the Strong Condensation Containment Apparatus (SCCA). Key phenomena that can be expected in small modular reactor (SMR) containments, given their small size and external passive water cooling, are explored, including how well the codes replicate stratification between a hot upper layer and a cooler under layer. This overall thermalhydraulics behaviour impacts other important phenomena, like heat transfer and aerosol deposition. MELCOR, an integrated severe accident code, and GOTHIC, a thermalhydraulic and containment code, were used in benchmarking activities, wherein the experimental results were compared to their simulation results. The findings demonstrated MELCOR’s capabilities to simulate the SCCA experiments and GOTHIC’s strength in predicting multiphase flow and thermalhydraulics in containment and cooling systems. In addition, the benchmark comparisons provided new insights toward modelling experiments with these codes as well as the behaviour observed in the SCCA experiment. These findings will guide accident management and emergency preparedness requirements for SMRs.

Topological valley Hall polariton condensation.

A photonic topological insulator features robust directional propagation and immunity to defect perturbations of the edge/surface state. Exciton-polaritons, that is, the hybrid quasiparticles of excitons and photons in semiconductor microcavities, have been proposed as a tunable nonlinear platform for emulating topological phenomena. However, mainly due to excitonic material limitations, experimental observations so far have not been able to enter the nonlinear condensation regime or only show localized condensation in one dimension. Here we show a topological propagating edge state with polariton condensation at room temperature and without any external magnetic field. We overcome material limitations by using excitonic CsPbCl3 halide perovskites with a valley Hall lattice design. The polariton lattice features a large bandgap of 18.8 meV and exhibits strong nonlinear polariton condensation with clear long-range spatial coherence across the critical pumping density. The geometric parameters and material composition of our nonlinear many-body photonic system platform can in principle be tailored to study topological phenomena of other interquasiparticle interactions.

GFP chromophore derived amphiphiles containing [12]aneN3 and biotin moieties as bio-imaging and targeting nonviral gene vectors

Gene therapy is a promising treatment, that brings the necessary opportunity to cure human genetic and major diseases, but it is hampered by the lack of safe and efficient gene delivery vectors. In this study, four amphiphiles were derived from GFP chromophore benzylimidazolidinone (G) through modifications with oxypropyl (1) or methylene (2) linked di(triazole-[12]aneN3) (M) in the presence or absence of tumor-targeting biotin (B) moiety, GMB-1/2 and GM-1/2. The four compounds showed excellent aggregation-induced emission (AIE) characteristics, strong DNA condensation abilities, and good biocompatibility. Among them, GMB-1, which containing targeting biotin moiety and a flexible propoxy linker, showed the highest transfection efficiency in three cell lines. The luciferase transfection efficiency of GMB-1 was as high as 15.2 times that of Lipofectamine 2000 (Lipo2000) without auxiliary lipid DOPE, and its gene therapy effect of delivering the p53 gene was also significantly better than that of Lipo2000 in HeLa cells due to its obvious targeting property. Fluorescence tracing experiments indicated that GMB-1 was able to quickly carry DNA into cells, to successfully escape from lysosomes, then to release DNA, and at last to smoothly deliver DNA into the nucleus. Moreover, its EGFP transfection efficiency in zebrafish reached 1.7 times that of Lipo2000. The excellent performance of GMB-1 demonstrated that the appreciative incorporation of GFP chromophore, di(triazole-[12]aneN3), and biotin moieties into the nonviral gene vectors provided a promising strategy for their clinical applications.

Oort Cloud and sednoid formation in an embedded cluster, I: Populations and size distributions

In this paper we report on massive computer simulations aimed to clarify the formation of an Oort Cloud and the adjoining sednoid population during the earliest times of the solar system due to the perturbing effects of the Sun’s birth aggregate, for which we use different embedded cluster models. We define the sednoid population to have semi-major axes between 100 and 1600 astronomical units, and it can be seen as the innermost extension of the Oort Cloud. By also restricting the orbits to perihelion distances exceeding 60 astronomical units, the sednoid population can be regarded as dynamically inert with respect to both planetary and Galactic influences. It includes the objects (90377) Sedna, 2012 VP113 and (541132) Leleākūhonua. We start by creating 12 cluster models, using the NBODY6++GPU code, with three random realisations of four physically different models. In each of these we select six random solar template stars and equip those with a planetary system composed of Jupiter, Saturn and 4000 massless planetesimals representing a population of stray planetesimals in the Jupiter–Saturn zone with a total mass assumed to be about 20 Earth masses. From dynamical simulations of all these 72 variants of the early solar system including the cluster perturbations, we derive the total numbers and orbital characteristics of the sednoid and Oort Cloud populations, including the size distributions resulting from the limiting effects of solar nebula gas drag on extraction efficiency. We find that the predicted number of sednoids varies dramatically depending on the orbital evolution of the solar template star in the cluster. In general, numbers consistent with the existence of the observed sednoids is an expected outcome only for a birth aggregate with a strong central condensation and a relatively long lifetime of the residual gas, whereas other cluster models tend to fail to explain this. In the most successful, concentrated cluster models, we predict the existence of an as yet unseen population of at least 108 km-sized sednoids. However, we note that these cluster models produce an overheated inclination distribution at variance with the observed inclinations. Hence, we conclude that our study points to a possible, severe problem of the embedded cluster scenario in explaining the origin of the sednoids. The Oort Cloud predicted to originate in local, Jupiter–Saturn planetesimals by our simulations amounts to ∼10% of the estimated, current size of the entire Oort Cloud. This shows that such comets, likely characterised by Earth-like D/H ratios, may be a minority though a significant one. In an accompanying paper we discuss the extraction dynamics in some detail, based on the same simulations as here.

Experimental and theoretical studies on water adsorption and capillary condensation in nanopores of calcium carbonate

Understanding the water vapor sorption in nanopores has significant implications for hydrocarbon extraction and waste storage. This study presents gravimetric water sorption isotherms of nanoporous calcium carbonates. A methodology for quantifying equilibrium water sorption through matrix potential, even as the matrix potential approaches zero is introduced. This method facilitated the determination of adsorption via the Derjaguin‒Landau‒Verwey‒Overbeek (DLVO) theory and of capillary condensation, including the conjugate state, based on Young's Laplace equation. The relative errors between the experimental and calculated values ranged from 0.24% to 10.42%. Quantitative parameters characterizing the water distribution were calculated, and their dependences on water sorption were analyzed. The increase in water sorption over time exhibited a gradual decline, which was better described by a second-order exponential decay function. The stable decline point of the sorption rates ranged from 13.24% to 22.47% of the total time. In most cases, water vapor sorption in the pores is dominated by adsorption, with nanopores showing enhanced adsorption due to weaker inhibition of sidewall effects compared to an increase in adsorption sites. Notably, a substantial increase in equilibrium water sorption occurs when the matrix potential exceeds −106 MPa, corresponding to a relative humidity exceeding 96.6%, indicating strong capillary condensation. Additionally, nanoscale pores exhibit a pronounced propensity for capillary condensation when the pore throat diameter is less than 3.5 nm. These findings enhance our understanding of water sorption in tight rock formations when direct measurements are unavailable, with implications for estimating multiphase fluid transport in unconventional reservoirs.

Noise-induced collective actuation in active solids.

Collective actuation describes the spontaneous synchronized oscillations taking place in active solids when the elasto-active feedback, which generically couples the reorientation of the active forces and the elastic stress, is large enough. In the absence of noise, collective actuation takes the form of a strong condensation of the dynamics on a specific pair of modes and their generalized harmonics. Here we report experiments conducted with centimetric active elastic structures, where collective oscillation takes place along the single lowest energy mode of the system, gapped from the other modes because of the system's geometry. Combining the numerical and theoretical analysis of an agent-based model, we demonstrate that this form of collective actuation is noise-induced. The effect of the noise is first analyzed in a single-particle toy model that reveals the interplay between the noise and the specific structure of the phase space. We then show that in the continuous limit, any finite amount of noise turns this new form of transition to collective actuation into a bona fide supercritical Hopf bifurcation.

Unravelling DNA Organization with Single-Molecule Force Spectroscopy Using Magnetic Tweezers.

Genomes carry the genetic blueprint of all living organisms. Their organization requires strong condensation as well as carefully regulated accessibility to specific genes for proper functioning of their hosts. The study of the structure and dynamics of the proteins that organize the genome has benefited tremendously from the development of single-molecule force spectroscopy techniques that allow for real-time, nanometer accuracy measurements of the compaction of DNA and manipulation with pico-Newton scale forces. Magnetic tweezers, in particular, have the unique ability to complement such force spectroscopy with the control over the linking number of the DNA molecule, which plays an important role when DNA-organizing proteins form or release wraps, loops, and bends in DNA. Here, we describe all the necessary steps to prepare DNA substrates for magnetic tweezers experiments, assemble flow cells, tether DNA to a magnetic bead inside a flow cell, and manipulate and record the extension of such DNA tethers. Furthermore, we explain how mechanical parameters of nucleoprotein filaments can be extracted from the data.

Experimental Study on the Control Mechanism of Non-Equilibrium Retrograde Condensation in Buried Hill Fractured Condensate Gas Reservoirs

During the depletion development of condensate gas reservoirs, when the formation pressure drops below the dew point pressure, the condensate oil and natural gas systems are in the non-equilibrium state of foggy retrograde condensation. The rational use of the non-equilibrium phase characteristics of the foggy retrograde condensation phenomenon during the development process will be beneficial to the recovery of condensate oil and natural gas. In order to clarify the retrograde condensation control mechanism during the non-equilibrium depletion development of condensate gas reservoirs, the phase characteristics of a condensate oil and gas system were studied by constant composition expansion and constant volume depletion experiments. Then, on the basis of a long core depletion experiment and chromatographic analysis experiment, the influence of different pressure drop speeds, fluid properties, and reservoir physical properties on the control effect of non-equilibrium retrograde condensation after the coupling of the fluid retrograde condensation and reservoir core is analyzed. The results show that during the pressure decline process, the condensate oil and gas system will produce a strong foggy retrograde condensation phenomenon, with the saturation of the retrograde condensate increasing and then decreasing. The cumulative recovery of the condensate oil and natural gas, as well as the mass fraction of the heavy components in the condensate oil, increase with the increase in the depletion rate. Different fluid properties and reservoir physical properties have a great influence on the cumulative recovery degree of the condensate oil, and have little influence on the recovery degree of the natural gas. This work has a certain guiding role for the stable production and enhanced recovery of fractured condensate gas reservoirs in subsurface structures of metamorphic rocks.

Effects of heating configuration and operating parameters on heat transfer and interfacial physics of microgravity flow boiling with subcooled inlet conditions – Experiments onboard the International Space Station

This study is part of the Flow Boiling and Condensation Experiment (FBCE), a collaborative effort between the Purdue University Boiling and Two-Phase Flow Laboratory (PU-BTPFL) and the NASA Glenn Research Center. The FBCE fitted with the Flow Boiling Module (FBM) was launched to the International Space Station (ISS) in August 2021 and experiments were successfully performed from February to July 2022 to amass a large microgravity-flow-boiling database. This study is focused on heat transfer and flow visualization of microgravity flow boiling of n-Perfluorohexane in a rectangular channel of 5.0 mm height, 2.5 mm width (heated), and 114.6 mm length, with subcooled inlet conditions. High-speed-video photography is utilized to present flow patterns and temporal interfacial behavior. Heat transfer results are presented in the form of flow boiling curves and both parametric curves and streamwise profiles of wall temperature and heat transfer coefficient. Firstly, the parametric effects of mass velocity (199.4 – 3200.0 kg/m2s), inlet subcooling (0.2 – 46.0°C), and inlet pressure (124.2 – 176.7 kPa), on the aforementioned aspects are assessed for double-sided heating to establish them for a microgravity environment. Of these three parameters, mass velocity and inlet subcooling mostly determine the microgravity flow boiling behavior, while inlet pressure plays an insignificant role. Flow patterns for double-sided heating are more complex than those for single-sided heating due to interaction between the two vapor layers. Vapor interaction is minimized at high subcoolings and high mass velocities due to strong condensation offered by the subcooled bulk liquid layer separating them. Despite the different flow patterns, both single- and double-sided heating generally result in similar parametric trends and local heat transfer coefficients for similar operating conditions. Flow instabilities manifest as temporal flow anomalies and temperature oscillations, and their severity increases with increasing boiling number. Secondly, the effects of heating configuration are analyzed by comparing and contrasting several aspects of single- and double-sided heating data. The heat fluxes at which onset of nucleate boiling degradation (ONBD) and critical heat flux (CHF) occur are distinctly different for single- and double-sided heating. There exists a threshold inlet subcooling demarcating the dominance of flow acceleration and condensation effects in vapor removal from the near-wall region and replenishment of fresh liquid for boiling. Above the threshold, condensation from the near-wall region is dominant and single-sided heating yields higher heat fluxes, and below it, acceleration is dominant and double-sided yields higher heat fluxes. At mass velocity in the range of 200 – 2400 kg/m2s, the threshold inlet subcooling lies in the approximate range of 20 – 30°C (corresponding inlet quality of roughly -0.40 – -0.20).

Two types of Tibetan Plateau vortex genesis in June and the associated mechanisms

The Tibetan Plateau vortex (TPV) is a key system triggering rainfall over the Tibetan Plateau (TP) during the boreal summer. The TPV genesis mechanisms are complicated and its classification is a great challenge. This study attempts to elucidate these aspects. By introducing the standardized index of 24-h increment of equivalent potential temperature Delta_{24h} theta_{{text{e}}} at 500 hPa, all the TPV cases generated in June between 1980 and 2016 are classified as either positive or negative. Composite analysis is subsequently applied to the extremes of these two types, i.e., the first and last fifth-percentile cases with extremely negative and positive standardized Delta_{24h} theta_{{text{e}}}, respectively. Results indicate that 70% of them occur in relatively warmer and wetter environments, with diabatic heating dominating the positive type and the dynamic effect of large-scale circulation dominating the negative type. For the extremely positive cluster, the geopotential-height increment over the TP exhibits a negative/west–positive/east dipole, which enhances the southerly flow over the western TP, while forming surface water–vapor convergence. Consequently, strong condensation heating occurs near the sub-cloud level, resulting in the development of potential vorticity below and eventually TPV genesis. For the negative cluster, local shear lines at 500 hPa and upstream troughs at 250 hPa occur at the TPV genesis location. In conjunction with anomalous westerlies, positive potential vorticity is generated in situ due to zonal advection. The retardation caused by the Kunlun Mountains on the impinging westerly flow associated with side-boundary friction also contributes to TPV genesis southeast of the mountains.

Pyrrole-2-carboxaldehydes: Origins and Physiological Activities.

Pyrrole-2-carboxaldehyde (Py-2-C) derivatives have been isolated from many natural sources, including fungi, plants (roots, leaves, and seeds), and microorganisms. The well-known diabetes molecular marker, pyrraline, which is produced after sequential reactions in vivo, has a Py-2-C skeleton. Py-2-Cs can be chemically produced by the strong acid-catalyzed condensation of glucose and amino acid derivatives in vitro. These observations indicate the importance of the Py-2-C skeleton in vivo and suggest that molecules containing this skeleton have various biological functions. In this review, we have summarized Py-2-C derivatives based on their origins. We also discuss the structural characteristics, natural sources, and physiological activities of isolated compounds containing the Py-2-C group.

Assembly of polyelectrolyte star block copolymers at the oil-water interface.

To understand and resolve adsorption, reconfiguration, and equilibrium conformations of charged star copolymers, we carried out an integrated experimental and coarse-grained molecular dynamics simulation study of the assembly process at the oil-water interface. This is important to guide development of novel surfactants or amphiphiles for chemical transformations and separations. The star block copolymer consisted of arms that are comprised of hydrophilic-hydrophobic block copolymers that are covalently tethered via the hydrophobic blocks to one point. The hydrophobic core represents polystyrene (PS) chains, while the hydrophilic corona represents quaternized poly(2-vinylpyridine) (P2VP) chains. The P2VP is modeled to become protonated when in contact with an acidic aqueous phase, thereby massively increasing the hydrophilicity of this block, and changing the nature of the star at the oil-water interface. This results in a configurational change whereby the chains comprising the hydrophilic corona are significantly stretched into the aqueous phase, while the hydrophobic core remains solubilized in the oil phase. In the simulations, we followed the kinetics of the anchoring and assembly of the star block copolymer at the interface, monitoring the lateral assembly, and the subsequent reconfiguration of the star via changes in the interfacial tension that varies as the degree-of-protonation increases. At low fractions of protonation, the arm cannot fully partition into the aqueous side of the interface and instead interacts with other arms in the oil phase forming a network near the interface. These insights were used to interpret the non-monotonic dependence of pH with the asymptotic interfacial tension from pendant drop tensiometry experiments and spectral signatures of aromatic stretches seen in vibrational sum frequency generation (SFG) spectroscopy. We describe the relationship of interfacial tension to the star assembly via the Frumkin isotherm, which phenomenologically describes anti-cooperativity in adsorbing stars to the interface due to crowding. Although our model explicitly considers long-range electrostatics, the contribution of electrostatics to interfacial tension is small and brought about by strong counterion condensation at the interface. These results provide key insights into resolving the adsorption, reconfiguration, and equilibrium conformations of charged star block copolymers as surfactants.

Examining the dust of the tailless Oort-cloud comet C/2020 T2

We report our latest analysis of the Oort-cloud comet C/2020 T2 (also named Palomar or T2) observed at 2.06 au from the Sun (phase angle of 28.°5) roughly two weeks before perihelion. It lacks a significant dust tail in scattered light, showing a strong central condensation of the coma throughout the apparition that is reminiscent of so-called Manx comets. Its spectral slope of polarized light increases and decreases in the J (1.25 μm) and H (1.65 μm) bands, respectively, resulting in an overall negative (blue) slope (−0.31 ±0.14% μm−1 ) in contrast to the red polarimetric color of active comets observed at similar geometries. The average polarization degree of T2 is 2.86±0.17% for the J and 2.75±0.16% for the H bands. Given that near-infrared wavelengths are sensitive to the intermediate-scale structure of cometary dust (i.e., dust aggregates), our light-scattering modeling of ballistic aggregates with different porosities and compositions shows that the polarimetric properties of T2 are compatible with low-porosity (~66%), absorbing dust aggregates with negligible ice contents on a scale of 10–100 μm (density of ~652 kg m−3). This is supported by the coma morphology of T2 which has a viable β (the relative importance of solar radiation pressure on dust particles) range of ≲10−4. The secular evolution of r-band activity of T2 from archival data reveals that the increase in its brightness accelerates around 2.4 au pre-perihelion, with its overall dust production rate that is about 100 times smaller than those of active Oort-cloud comets. We also found an apparent concentration of T2 and Manx comets toward ecliptic orbits. This paper underlines the heterogeneous nature of Oort-cloud comets, which may be investigated in the near future with dedicated studies of their dust characteristics.

Rapid variations of Si IV spectra in a flare observed by interface region imaging spectrograph at a sub-second cadence

We report on observations of highly-varying Si IV 1402.77 Å line profiles observed with the Interface Region Imaging Spectrograph (IRIS) during the M-class flare from 18 January 2022 at an unprecedented 0.8 s cadence. Moment analysis of this line observed in flare ribbon kernels showed that the intensity, Doppler velocity, and non-thermal broadening exhibited variations with periods below 10 s. These variations were found to be correlated with properties of the Gaussian fit to a well-resolved secondary component of the line redshifted by up to 70 km s−1, while the primary component was consistently observed near the rest wavelength of the line. A particularly high correlation was found between the non-thermal broadening of the line resulting from the moment analysis and the redshift of the secondary component. This means that the oscillatory enhancements in the line broadening were due to plasma flows (away from the observer) with varying properties. A simple de-projection of the Doppler velocities of the secondary component based on a three-dimensional reconstruction of flare loops rooted in the kernel suggests that the observed flows were caused by downflows and compatible with strong condensation flows recently predicted by numerical simulations. Furthermore, peaks of the intensity and the trends of Doppler velocity of the Gaussian fit to the secondary component (averaged in the ribbon) were found to correspond to one of the quasi-periodic pulsations (QPPs) detected during the event in the soft X-ray flux (as measured by the Geostationary Operational Environmental Satellite, GOES) and the microwave radio flux (as measured by the Expanded Owens Valley Solar Array, EOVSA). This result supports a scenario in which the QPPs were driven by repeated magnetic reconnection.

Incoherent charge transport in an organic polariton condensate

We study how polariton condensation modifies charge transport in organic materials. In typical organic materials, charge transport proceeds via incoherent hopping. We therefore provide an approach to determine how the rate and final state of this hopping process is affected by strong matter-light coupling and polariton condensation. We show how the hopping process may create excitations when starting from a state with a finite excitation density. That is, how hopping can change the state of a lower polariton condensate by creating upper polaritons, optically inactive excitonic dark states, or by exciting vibrational sidebands. While the matrix elements for these processes can be large, for typical materials at room temperature, such excitations are suppressed by thermal factors, and ground state processes dominate. We thus study how the ground state hopping rate depends on condensate density, matter-light coupling, and cavity photon detuning. All these factors change the vibrational configuration associated with the optically active molecules, which can enhance or suppress hopping by increasing or decreasing the vibrational overlap with the state of a charged molecule. We show that hopping rates can be exponentially sensitive to detuning and condensate density, allowing an increase or decrease of hopping rate by two orders of magnitude.

Aerosol retention within submerged Containment-Type iPWRs: Experiments and modeling

Integral pressurized water reactor (iPWR) designs employing submerged, high-pressure steel containment vessels rely on water in the outer operating pool as the primary heat sink during an accident. This drives very strong steam condensation, and along with it, strong diffusiophoretic deposition rates for fission product aerosols. In this study, a loss-of-containment isolation accident is proposed and simulated with MELCOR, where the strong condensation/diffusiophoresis is the last barrier preventing direct radionuclide releases to the environment. This is supported by experiments that measured the thermal stratification, steam condensation rates, and aerosol deposition rates that would be experienced in a prototypic, iPWR-like geometry. The development of the steam layer, whose thickness was proportional to steam injection rates, impacted the aerosol deposition by limiting the area over which condensation-driven diffusiophoresis could occur. Diffusiophoresis was still confirmed to be the primary mechanism for aerosol deposition, with observed rates that were in line with established theory.

In situ small-angle X-ray scattering reveals strong condensation of DNA origami during silicification

Silicification of DNA origami structures increases their stability and provides chemical protection. Yet, it is unclear whether the whole DNA framework is embedded or if silica just forms an outer shell and how silicification affects the origami’s internal structure. Employing in situ small-angle X-ray scattering (SAXS), we show that addition of silica precursors induces substantial condensation of the DNA origami at early reaction times by almost 10 %. Subsequently, the overall size of the silicified DNA origami increases again due to increasing silica deposition. We further identify the SAXS Porod invariant as a reliable, model-free parameter for the evaluation of the amount of silica formation at a given time. Contrast matching of the DNA double helix Lorentzian peak reveals silica growth also inside the origami. The less polar silica forming within the origami structure, replacing more than 40 % of the internal hydration water, causes a hydrophobic effect: condensation. DNA origami objects with flat surfaces show a strong tendency towards aggregation during silicification, presumably driven by the same entropic forces causing condensation. Maximally condensed origami displayed thermal stability up to 60 °C. Our studies provide insights into the silicification reaction allowing for the formulation of optimized reaction protocols.

Advanced characterization of hydrothermal flows within recharge and discharge areas using rare earth elements, proved through a case study of two-phase reservoir geothermal field, in Southern Bandung, West Java, Indonesia

Rare earth element (REE) analysis is effective for tracing water–rock interactions and solute transport in geothermal and groundwater systems. This study aimed to clarify hydrothermal flows within recharge and discharge areas of a geothermal system. We selected a well-known high-temperature geothermal field with two-phase reservoir in Southern Bandung, West Java (Indonesia) as a case study target, and collected 31 river/spring samples and 8 well rock samples. The measured total REE series concentrations ranged widely in the water samples, i.e., rivers: 3.4–35 ppt, cold springs: 0.3–284 ppt, and hot springs: 1.4 ppt to 102 ppm. Enrichment of light REEs (LREEs) in the water samples was characterized more clearly by Post Archean Australian Shale normalization than by chondrite normalization. Speciation analysis derived the following interpretations: dissolved REEs in the river water originated from free ions or Ln3+ that are typically contained in near-surface groundwater, and the dominant components were carbonate (LnCO3+) and Ln3+ complexes in the cold springs and LnCO3+ complexation in the hot springs. Steam and gas condensation into less-oxygenated groundwater can be indicated by rich LnCO3+. Only one hot spring was interpreted as being directly connected with the reservoir by strong H2S condensation and LREE enrichment. The water of the other cold and hot springs probably underwent dilution, evaporation, and magmatic gas condensation through shallow, deep, and deep-perched aquifers, permeable zones, and a major fault within the recharge and discharge areas. REE results also suggest that the main constituents of the aquifers are carbonates and silicate minerals and hydrothermally altered lahars, andesitic lava, and pyroclastic flow deposits. REEs facilitate detailed interpretation of geochemistry facies in shallow–deep waters of a hydrothermal system. Finally, integration of the analysis results of REEs, major anions and cations, water isotopes, and strontium isotopes improved a conceptual model of groundwater flows and recharge–discharge interactions in aquifers feeding a geothermal reservoir.

Estimating the two graph dextran-stearic acid-spermine polymers based on iron oxide nanoparticles as carrier for gene delivery.

Non-viral gene carriers have shown noticeable potential in gene delivery because of limited side effects, biocompatibility, simplicity, and the ability to take advantage of electrostatic interactions. However, the low transfection rate of non-viral vectors under physiological conditions is controversial. This study aimed to decrease the transfection time using a static magnetic field. We used self-assembled cationic polysaccharides based on dextran-stearic acid-spermine (DSASP) conjugates associated with Fe3 O4 superparamagnetic nanoparticles to investigate their potential as gene carriers to promote the target delivery. Our findings illustrate that the magnetic nanoparticles are spherical with a positive surface charge and exhibit superparamagnetic behavior. The DSASP-pDNA/Fe3 O4 complexes offered a strong pDNA condensation, protection against DNase degradation, and significant cell viability in HEK 293T cells. Our results demonstrated that although conjugation of stearic acid could play a role in transfection efficiency, DSASP magnetic carriers with more spermine derivatives showed better affinity between the amphiphilic polymer and the negatively charged cell membrane.

Nanometer-Scale Spatial and Spectral Mapping of Exciton Polaritons in Structured Plasmonic Cavities.

Exciton polaritons (EPs) are ubiquitous light-matter excitations under intense investigation as test beds of fundamental physics and as components for all-optical computing. Owing to their unique attributes and facile experimental tunability, EPs potentially enable strong nonlinearities, condensation, and superfluidity at room temperature. However, the diffraction limit of light and the momentum content of fast electron probes preclude the characterization of EPs in nanoscale structured cavities exhibiting energy-momentum dispersion. Here we present fully relativistic analytical theory and companion numerical simulations showing that these limitations can be overcome to measure EPs in periodic nanophotonic cavities on their natural energy, momentum, and length scales via lattice electron energy gain spectroscopy. With the combined high momentum resolution of light and nanoscale spatial resolution of focused electron beams, lattice electron energy gain spectroscopy can expose deeply subwavelength EP features using currently available monochromated, aberration-corrected scanning transmission electron microscopes.