Emulsion Experiments Research Articles

Nuclear emulsion film production system for experiments in full-area scanning and analysis era

Research utilizing the sub-micron three-dimensional spatial resolution of nuclear emulsion detectors has been expanding in various fields, triggered by the development of automated emulsion scanning technology. This paper describes a new production system capable of supplying several thousand square meters of nuclear emulsion film per year. The development and introduction of improved emulsion gel, knife coating, and drying equipment have enabled the mass production of double-side coated nuclear emulsion films with thick emulsion layers suitable for full-area scanning and analysis. This system has played an essential role in numerous nuclear emulsion experiments.

β-Cyclodextrin modified SiO2 nanofluid for enhanced oil recovery

Recently, with the deterioration of oil storage conditions, the extraction of oil has been limited. In this experiment, β-cyclodextrin (β-CD) was grafted onto the surface of SiO2 nanoparticles. The structure and morphology of nanoparticles were analyzed by various characterization tools to effectively validate the synthesis of nanomaterials. In addition, it was experimentally demonstrated that the developed β-CD-SiO2 nanofluid has excellent stability and salt resistance. Finally, the comparative studies of the nanofluids were carried out by wettability, interfacial tension (IFT), Pickering emulsion, viscosity, and core flooding experiments. The results showed that β-CD-SiO2 nanofluid exhibited better performance: β-CD-SiO2 nanofluid changed the contact angle (CTA) of carbonate plate from 131.5º to 90.1º; the IFT was significantly reduced from about 35 mN/m to 22.5 mN/m; the emulsion droplets formed were fine and dense; the viscosity increased and viscosity not changed with shear rate; and total crude oil recovery up to 59.2%, 23.9% higher than using water drives. Overall, these results showed the great potential of β-CD-SiO2 nanofluid in ultra-low permeability reservoirs.

Flexible Z-scheme heterojunction membrane reactors for visible-light-driven antibiotic degradation and oil-water separation

This study fabricated PENS/TA/ZIF-67@Ag2S (PZA), a double self-cleaning network antifouling polymer membrane reactor, by the non-solvent-induced phase separation (NIPS) method. Due to the synergistic effect of the double self-cleaning structure, it showed an excellent separation efficiency of 99.65% and a high flux of 1198.011 L·m−2·h−1 in the separation of oil-in-water emulsion experiments. After eight cycles, Oil-water separation efficiency remains >99% recyclable. The Z-type heterogeneous conjunctival reactor we constructed has a high-efficiency degradation rate of 99.94% and a mineralization rate of 80.315% for sulfamethoxazole (SMX) within 120 min. From the results of mechanical properties, TGA and DSC, it can be seen that PZA has good strength, toughness and high temperature resistance. According to the experimental analysis of active substances, the active ingredients produced by PZA are •OH., h+, •O2–. Based on Density functional theory (DFT) calculations and intermediate analysis, sulfamethoxazole's active sites and degradation pathways (SMX) were explored. According to the Quantitative Structure-Activity Relationship (QSAR) of the Toxicity Estimation Software Tool (TEST), the toxicity of the intermediates produced during the degradation of SMX was predicted. This study provides a feasible strategy for fabricating Z-scheme metal-organic framework (MOF)-based polymer membrane reactors for efficient green antibiotic wastewater treatment and oil-water self-cleaning.

The effects of a novel Bio-based surfactant derived from the Acacia concinna plant on chemical enhanced oil recovery in the presence of various salts and a synthesized HSPAM polymer

In this investigation, a unique idea of using a green surfactant derived from Acacia concinna (AC) plant and a hydrophobically modified copolymer consistingof acrylamide and styrene (HSPAM) for chemical enhanced oil recovery (CEOR) was studied. Firstly, the characteristics of AC green surfactant were comprehensively examined using different standard analyses, such as thermogravimetric analysis (TGA), nuclear magnetic resonance (NMR) spectroscopy, and Fourier-transform infrared spectroscopy (FTIR) techniques. The thermal stability test of the AC green surfactant demonstrated an acceptable 1.93% weight loss at the 80 °C (reservoir temperature). Additionally, 1H NMR and FT-IR investigations proved the structure of the saponin compound as the surfactant agent. Then, the compatibility tests revealed no precipitation at various concentrations of different salts. The efficiency of the AC green surfactant and HSPAM was examined with three different salts, including K2SO4, MgSO4, and NaCl, as three common salts present in the formation brine (FB) with salinities up to 97,000 ppm. Different experiments, including contact angle and interfacial tension (IFT) measurements, zeta potential measurements, emulsion and core flooding experiments were conducted and the efficiency of these materials for CEOR purposes was examined. The IFT results revealed that 1000 ppm is the critical micelle concentration (CMC) of AC green surfactant in deionized water (DIW). Based on the measured IFT and contact angle values, the most effective salt was K2SO4, followed by NaCl, and MgSO4. The addition of 2000 ppm of HSPAM polymer as the optimum concentration of HSPAM was very efficient in improving the performance of AC green surfactant and producing a higher quality of Winsor type III emulsion. The maximum oil recovery factor of 71.17% was achieved when 1000 ppm of AC green surfactant was injected as the tertiary recovery, and the value was further increased to 77.92% when 2000 ppm of HSPAM and 1000 ppm of AC green surfactant were injected as the tertiary recovery.

On geometrical interpretation of alignment phenomenon

The observed alignment of spots in the X-ray films in cosmic ray emulsion experiments is analyzed and interpreted in the framework of geometrical approach. It is shown that the high degree of alignment can appear partly due to the selection procedure of most energetic particles itself and the threshold on the energy deposition together with the transverse momentum conservation.

Has J-PARC E07 observed a [formula omitted] nuclear state?

The Strangeness S=−2 J-PARC E07 emulsion experiment published recently two new Ξ−–14N capture events, IRRAWADDY and IBUKI, identified by observing weak-decay sequences of pairs of single-Λ hypernuclei and interpreted as Ξ1s− and Ξ1p− nuclear bound states, respectively, with binding energies BΞ−1s=6.27±0.27 MeV and BΞ−1p=1.27±0.21 MeV. Ξ− capture events in emulsion play a major role in determining the Ξ-nuclear and the ΛΛ potential strengths. Here we question the assignment of a Ξ1s− nuclear bound state to IRRAWADDY and offer an alternative assignment as a near-threshold Ξ1p0–14C nuclear bound state, slightly admixed with a Ξ1p−–14N nuclear bound state component corresponding to IBUKI. We also question using IBUKI's BΞ−1p value as is to determine the Ξ-nuclear potential depth. Altogether, Ξ− capture events in 12C and 16O should prove less ambiguous than in 14N.

Momentum reconstruction of charged particles using multiple Coulomb scatterings in a nuclear emulsion detector

Abstract This paper describes a new method for momentum reconstruction of charged particles using multiple Coulomb scatterings in a nuclear emulsion detector with a layered structure of nuclear emulsion films and target materials. The method utilizes the scattering angles of particles precisely measured in the emulsion films. The method is based on the maximum likelihood to include the new information on the decrease of the energy as the particle travels through the detector. According to the Monte Carlo simulations, this method can measure momentum with a resolution of 10% for muons of ${500}\, {\rm MeV}/c$ passing through the detector perpendicularly. The momentum resolution is evaluated to be 10–20%, depending on the momentum and emission angle of the particle. By accounting for the effect of the energy decrease, the momentum can be reconstructed correctly with less bias, particularly in the low-momentum region. We apply this method to measure the momentum of muon tracks detected in the Neutrino Interaction research with Nuclear emulsion and J-PARC Accelerator (NINJA) experiment where the momentum is also measured independently by using the track range. The two measurements agree well within experimental uncertainties, verifying the method experimentally. This method will extend the measurable phase space of muons and hadrons in the NINJA experiment.

DropTrack—Automatic droplet tracking with YOLOv5 and DeepSORT for microfluidic applications

Deep neural networks are rapidly emerging as data analysis tools, often outperforming the conventional techniques used in complex microfluidic systems. One fundamental analysis frequently desired in microfluidic experiments is counting and tracking the droplets. Specifically, droplet tracking in dense emulsions is challenging due to inherently small droplets moving in tightly packed configurations. Sometimes, the individual droplets in these dense clusters are hard to resolve, even for a human observer. Here, two deep learning-based cutting-edge algorithms for object detection [you only look once (YOLO)] and object tracking (DeepSORT) are combined into a single image analysis tool, DropTrack, to track droplets in the microfluidic experiments. DropTrack analyzes input microfluidic experimental videos, extracts droplets' trajectories, and infers other observables of interest, such as droplet numbers. Training an object detector network for droplet recognition with manually annotated images is a labor-intensive task and a persistent bottleneck. In this work, this problem is partly resolved by training many object detector networks (YOLOv5) with several hybrid datasets containing real and synthetic images. We present an analysis of a double emulsion experiment as a case study to measure DropTrack's performance. For our test case, the YOLO network trained by combining 40% real images and 60% synthetic images yields the best accuracy in droplet detection and droplet counting in real experimental videos. Also, this strategy reduces labor-intensive image annotation work by 60%. DropTrack's performance is measured in terms of mean average precision of droplet detection, mean squared error in counting the droplets, and image analysis speed for inferring droplets' trajectories. The fastest configuration of DropTrack can detect and track the droplets at approximately 30 frames per second, well within the standards for a real-time image analysis.

Neutrino up-scattering via the dipole portal at forward LHC detectors

The significant neutrino flux at high rapidity at the LHC motivates dedicated forward detectors to study the properties of neutrinos at TeV energies. We investigate magnetic dipole interactions between the active neutrinos and new sterile states at emulsion and liquid argon experiments that could be located in a future Forward Physics Facility (FPF) downstream of the ATLAS interaction point. The up-scattering of neutrinos off electrons produces an electron recoil signature that can probe new regions of parameter space at the High Luminosity LHC (HL-LHC), particularly for liquid argon detectors due to low momentum thresholds. We also consider the decay of the sterile neutrino through the dipole operator, which leads to a photon that could be displaced from the production vertex. FPF detectors can test sterile neutrino states as heavy as 1 GeV produced through the dipole portal, highlighting the use of high energy LHC neutrinos as probes of new physics.

Towards a Standard Method for Estimating Fragmentation Rates in Emulsification Experiments

The fragmentation rate function connects the fundamental drop breakup process with the resulting drop size distribution and is central to understanding or modeling emulsification processes. There is a large interest in being able to reliably measure it from an emulsification experiment, both for generating data for validating theoretical fragmentation rate function suggestions and as a tool for studying emulsification processes. Consequently, several methods have been suggested for measuring fragmentation rates based on emulsion experiments. Typically, each study suggests a new method that is rarely used again. The lack of an agreement on a standard method has become a substantial challenge. This contribution critically and systematically analyses four influential suggestions of how to measure fragmentation rate in terms of validity, reliability, and sensitivity to method assumptions. The back-calculation method is identified as the most promising—high reliability and low sensitivity to assumption—whereas performing a non-linear regression on a parameterized model (as commonly suggested) is unsuitable due to its high sensitivity. The simplistic zero-order method is identified as an interesting supplemental tool that could be used for qualitative comparisons but not for quantification.

The development of novel nanofluid for enhanced oil recovery application

Recently, nanofluids' application in enhanced oil recovery (EOR) studies has been severely confined in low saline environments due to instability. In this study, a novel nanofluid was developed by conjugating an anionic surfactant to graphene oxide nanosheets (GONs) through electrostatic forces and compared with negatively charged colloidal silica nanoparticles. The surfactant conjugation on target GONs was confirmed by transmission electron microscopy, Fourier transforms infrared spectrometry and zeta potential. The developed nanofluid preserved a high salinity of 6 wt% NaCl and built more stable dispersions than bare silica nanofluid. The nanofluids' potential in recovering oil was comparatively studied by performing the viscosity, wettability, Pickering emulsion, and interfacial tension (IFT) experiments. Even though a tangible improvement of 1.48 cp was observed in the viscosity of Janus-GONs fluid after the dissolution of NaCl, this figure became negligible for silica fluid, by 0.07 cp. From the wetting values (θ), Janus-GONs changed the oil-wet wettability toward neutral-wet (89.9°), and silica nanoparticles toward partially water-wet (66.4°). Oil-in-water Pickering emulsions stabilized with the reinforced nanofluid remained fully stable compared to those of silica, which rapidly grew unstable. The reinforced nanofluid lowered interfacial tension by just under a third, which was attributed to its higher surface energy. In contrast, silica nanoparticles did not change interfacial tension sensibly. Micromodel experiments revealed that Janus-GONs yielded a considerable oil recovery of 79 % by restoring wettability to mixed-wet and reducing the viscous fingering phenomenon, compared to that of 53 % for silica. Based on the core flooding experiments, the percentage of oil recovered for Janus-GONs fluid was twice the silica nanofluid due to the higher capillary number (1 × 10−4) compared to the silica (8.7 × 10−6). Viscosity improvement was proposed as a new EOR mechanism next to wettability alteration and IFT reduction. Overall, the Janus nanofluid can be a ground-breaking nanomaterial for EOR.

Studying droplet retention in porous media by novel microfluidic methods

Transport of oil droplets through porous media is an important topic in the oil and gas industry. Oil droplets that are present in produced water contribute to injectivity decline during re-injection due to retention in pores. In the literature, the retention phenomenon is typically studied by means of core/packed bed flooding, which struggles to provide a simple and inexpensive way to visualize retention events at the pore scale. This paper demonstrates a microfluidic method for studying the transport of dilute oil-in-water emulsions through porous media. The method allows identification of every single retention event at the capillary level and quantitative analysis of the spatial distribution of the retained droplets over pore volumes injected. Experiments were carried out for monodisperse and tailored polydisperse emulsions. Moreover, several droplet sizes, flow rates and dispersed phase concentrations were tested. The results showed that the droplet size has a dramatic effect on the pore clogging. Droplets that are larger than pore throats underwent complete retention, while droplets that are smaller than pore throats showed little to no retention in the monodisperse emulsion experiments. Additionally, the experiments with polydisperse emulsions showed that the larger droplets are facilitators for the retention of the smaller droplets, and the latter are unlikely to experience significant retention independently of the former. The flow rates affected flow re-entry mechanisms of the larger droplets, while for the smaller droplets it influenced only the number of retention events. It was identified that dispersed phase concentration has a significant effect in experiments with limited pore volumes injected. At low concentration, the obtained statistical sample was not sufficiently large to unravel the trends. The developed method presents a solid foundation for further experiments and developments in microfluidic studies of the emulsion transport.

Synthesis and Characterization of a Novel Multibranched Block Polyether Demulsifier by Polymerization.

Various flooding technologies were applied in the middle and late stages of the oilfield, which made the heavy oil emulsion receive much concern because of its high stability and separation difficulty. In our paper, alcohol molecules were used as initiators and multibranched block copolymers were synthesized through open-loop polymerization technology. A variety of novel modified block polyether demulsifiers with demulsification activity were finally synthesized through water-soluble modification and oil-soluble modification, which achieved efficient demulsification of heavy oil emulsions. Hydrophile–lipophile balance (HLB) values and surface tension were used to characterize demulsifiers. In addition, their demulsification efficiency was evaluated by measuring the amount of dehydration in the separated heavy oil emulsion experiments. The experimental results showed that within 5 h, the demulsification effect of the water-soluble demulsifier is better than that of the oil-soluble demulsifier. When the HLB value of the demulsifier reaches a certain value, the dehydration rate and the demulsification effect reach the highest point. When the amount of demulsifier is 50 μg/g and the demulsification temperature is 85 °C, the dehydration rate of the water-soluble demulsifier X-6 reached 91%, the water quality was clear, and the demulsification effect reached its peak. This work will provide a novel and efficient demulsifier for demulsification and dehydration of heavy oil emulsions.

Observation of a Significant Flow of Neutral Galactic Particles in the Stratosphere at Energies in the Range of 1013–1015 eV

A reanalysis of experimental data from the RUssia-Nippon JOint Balloon (RUNJOB) emulsion experiment on the basis of a new method aimed at searches for primary galactic particles in events identified as those of nucleon-nucleus interaction confirmed the original result that consisted in the absence of a large number (about 50%) of tracks of incident particles. A comparative analysis of such events where there is a detected primary track and where there is no primary track was performed in terms of the energy, angular distribution, and depth of penetration into x-ray emulsion chambers (XREC). The hypothesis that a neutral component is present in cosmic rays at the XREC exposure level is discussed.

Recalibration of the binding energy of hypernuclei measured in emulsion experiments and its implications * * Supported by the Key Research Program of the Chinese Academy of Science (XDPB09), the National Natural Science Foundation of China (11890714, 11775288, 11421505, 11520101004), the China Scholarship Council (201704910615), the U.S. Department of Energy, Office of Science (DE-FG02-89ER40531, DE-SC-0012704)

The separation energy for hypernuclei, denoted , measured in 1967, 1968, and 1973 are recalibrated using the current best estimates of the mass of particles and nuclei. The recalibrated are systematically larger (except in the case of He) than the originally published values by about 100 keV. The effect of this level of recalibration is very important for light hypernuclei, especially for the hypertriton. The early values measured in 1967, 1968, and 1973 are widely used in theoretical research, and the new results provide better constraints for the conclusions of such studies.

Ξ hyperons in the nuclear medium described by chiral NLO interactions

Properties of the baryon-baryon interactions in the strangeness $S=-2$ sector of chiral effective field theory at the next-to-leading order (NLO) level are explored by calculating $\Xi$ single-particle potentials in symmetric nuclear matter. The results are transformed to the $\Xi$ potential in finite nuclei by a local-density approximation with convolution by a Gaussian form factor to simulate finite-range effects. The $\Xi$ potential is repulsive in a central region, and attractive in a surface area when the $\Xi$ energy is low. The attractive pocket can lower the $\Xi^-$ $s$ and $p$ atomic states. The obtained binding energies in $^{12}$C and $^{14}$N are found to be conformable with those found in emulsion experiments at Japan's National Laboratory for High Energy Physics (KEK). $K^+$ spectra of $(K^-, K^+)$ $\Xi$ production inclusive processes on $^9$Be and $^{12}$C are also evaluated, using a semi-classical distorted wave method. The absolute values of the cross section are properly reproduced for $^9$Be, but the peak locates at a lower energy position than that of the experimental data. The calculated spectrum of $^{12}$C should be compared with the forthcoming result from the new experiments recently carried out at KEK with better resolution than before. The comparison would be valuable to improve the understanding of the $\Xi N$ interaction, the parametrization of which has still large uncertainties.

E-by-e fluctuations of initial conditions in interactions of light, intermediate and heavy nuclei at energies 4 - 200 GeV per nucleon

A better understanding of initial conditions of nuclear interactions is one of the most important heavy ion physics problems. The paper considers these problems in the centrality selected interactions of light (C, O, Ne) – (beam) and heavy (Au, Pb) – (beam) ions with light (C/N/O) – (target) and heavy (Ag/Br) – (target) nuclei using the data of JINR-AGS-SPS target emulsion experiments with limited statistics. To reveal a possible system structure dependence, the analyses of E-by-E fluctuations on the longitudinal event shape and multiplicity have been performed, vertically and horizontally.

A STUDY OF MULTIFRACTALITY AND PHASE TRANSITION IN HEAVY-ION COLLISIONS — EXPERIMENTAL DATA VERSUS MODEL SIMULATION

In this paper, we have investigated the presence of multifractality and the possibility of quark–hadron phase transition in the multiparticle production in [Formula: see text]O–AgBr, [Formula: see text]Si–AgBr and [Formula: see text]S–AgBr interactions at 4.5[Formula: see text]AGeV/[Formula: see text] in the framework of Ginzburg–Landau theory of second-order phase transition following the Takagi moment methodology. The same analysis with the factorial moment method has also been performed. Experimental results have been compared with the prediction of UrQMD and AMPT models. A comparison of experimental results with the analysis of UrQMD simulated RHIC data by the method of Takagi moment has also been presented. Comparison of experimental results with previous results of emulsion experiments has been mentioned.

Clogging of soft particles in two-dimensional hoppers.

Using experiments and simulations, we study the flow of soft particles through quasi-two-dimensional hoppers. The first experiment uses oil-in-water emulsion droplets in a thin sample chamber. Due to surfactants coating the droplets, they easily slide past each other, approximating soft frictionless disks. For these droplets, clogging at the hopper exit requires a narrow hopper opening only slightly larger than the droplet diameter. The second experiment uses soft hydrogel particles in a thin sample chamber, where we vary gravity by changing the tilt angle of the chamber. For reduced gravity, clogging becomes easier and can occur for larger hopper openings. Our simulations mimic the emulsion experiments and demonstrate that softness is a key factor controlling clogging: with stiffer particles or a weaker gravitational force, clogging is easier. The fractional amount a single particle is deformed under its own weight is a useful parameter measuring particle softness. Data from the simulation and hydrogel experiments collapse when compared using this parameter. Our results suggest that prior studies using hard particles were in a limit where the role of softness is negligible, which causes clogging to occur with significantly larger openings.

Characterization and study of microwave activation effects on the polystyrene tacticity

ABSTRACT13C Nuclear magnetic resonance proved to be an advantageous tool to determine the stereoregularity of polystyrene polymers. The latter was achieved through the analysis of the signal of the quaternary carbon and that of the carbon-p in the aromatic ring too. Styrene was polymerized through microwaves and conventional heating activation using two different polymerization techniques: emulsion and bulk. Microwave activation was performed in a mono-modal type device under the following experimental conditions: various initiator concentrations, an average irradiation power of 50 W, temperature of 70°C, and using a batch reactor for emulsion and bulk experiments. The results obtained in these experiments were compared with those obtained by conventional heating activation polymerization under the same initiator concentration and temperature conditions. Microwave-activated reactions resulted in shorter reaction times and higher yields. The tacticity of the polymer samples was not significantly altered, which lead to the conclusion that, in this case, the stereoregularity of polystyrene was not influenced by microwave irradiation.