Behavior Of Clouds Research Articles

Multifractal Analysis for Evaluating the Representation of Clouds in Global Kilometer‐Scale Models

AbstractClouds are one of the largest sources of uncertainty in climate predictions. Global km‐scale models need to simulate clouds and precipitation accurately to predict future climates. To isolate issues in their representation of clouds, models need to be thoroughly evaluated with observations. Here, we introduce multifractal analysis as a method for evaluating km‐scale simulations. We apply it to outgoing longwave radiation fields to investigate structural differences between observed and simulated anvil clouds. We compute fractal parameters which compactly characterize the scaling behavior of clouds and can be compared across simulations and observations. We use this method to evaluate the nextGEMS ICON simulations via comparison with observations from the geostationary satellite GOES‐16. We find that multifractal scaling exponents in the ICON model are significantly lower than in observations. We conclude that too much variability is contained in the small scales leading to less organized convection and smaller, isolated anvils.

The Method for Obtaining Shot Cloud Time Span and Range Dependence

When studying the behavior of a shot cloud in space, a variety of information and measurement systems can be applied, for example, based on light screens (photoelectronic blocking devices of a small ballistic measuring installation consisting of a linear emitter and an optical sensor based on a photodiode). To study the process of shot cloud movement in space and to assess its parameters (for example, length at a given range from the muzzle) correctly, it is advisable to have a simulation model of the optical sensor signal when the light screen is crossed by a shot cloud. Taking into account previous studies, it is necessary to know the magnitude of the scale parameter in the Rayleigh distribution describing the shot cloud in the direction of firing in time in order to obtain a similar model at some distance from the muzzle. A method that allows obtaining function of dependence of the mentioned scale parameter and the distance from the muzzle and based on real data from several optical sensors of light screens installed on the shooting track is proposed. The example of application the proposed method to obtain similar functions based on the results of processing optical sensor signals obtained in real experiments for cartridges loaded with three different shot types is given. The obtained dependences were approximated by polynomials of the first and second degree using the least squares method, and the error was estimated for various types of cartridges. Based on the obtained results, specific recommendations for the practical application of the developed method are proposed. The estimation of the confidence interval width for the expectation function of the shot cloud time span is performed. The ways of creating advanced signal simulation models from optical sensors of light screens when shooting with shot are outlined.

Hygroscopic growth and activation changed submicron aerosol composition and properties in the North China Plain

Abstract. Aerosol hygroscopic growth and activation under high-relative-humidity (RH) conditions significantly influence the physicochemical properties of submicron aerosols (PM1). However, this process remains poorly characterized due to limited measurements. To address this gap, we deployed an advanced aerosol–fog sampling system that automatically switched between PM1, PM2.5 and total suspended particulate (TSP) inlets at a rural site in the North China Plain in the cold season. The results revealed that aerosol swelling due to water vapor uptake influenced aerosol sampling under high-RH conditions by shifting the cut-off size of impactors. At subsaturated high RH (> 90 %), over 25 % of aerosol mass with dry diameters below 1 µm resided in supermicron ranges, while in supersaturated foggy conditions, more than 70 % of submicron aerosol migrated to supermicron ranges. Hygroscopic growth and activation particularly affected highly hydrophilic inorganic salts, shifting a significant number of submicron sulfate and nitrate particles to supermicron ranges, with 27 %–33 % at 95 % ≤ RH ≤ 99 % and more than 78 % under supersaturated foggy conditions. Moreover, more than 10 % of submicron biomass burning organic aerosols grew beyond 2.5 µm during fog events, while fossil-fuel-related organic aerosol (FFOA) remained dominantly in submicron ranges, suggesting inefficient aqueous conversion of FFOA. The two secondary organic aerosol (SOA) factors (OOA1 and OOA2) behaved differently under supersaturated conditions, with OOA2 exhibiting a higher activated fraction despite a lower oxygen / carbon ratio. A substantial increase in organic nitrate and organosulfur mass concentrations in activated droplets during fog events suggested aqueous conversions and formations of brown carbon with potential radiative impacts. Overall, our study highlights remarkably different cloud and fog processing behaviors between primary and secondary aerosols, which would benefit a better understanding of aerosol–cloud interactions under distinct atmospheric conditions.

Association and clouding behaviour of surfactants in aqueous solution of propranolol hydrochloride drug: Understanding of the effects of potassium salts and temperatures

The investigation of the assembly of lithium dodecyl sulfate (LDS) and cloudy creation of triton X-100 (TX-100) in aqueous solution of amphiphilic drug propranolol hydrochloride (PLH) has been carried out by electrical conductivity and cloud point estimation method respectively. The influences of three potassium electrolytes (KCl, K2SO4, and K3PO4) on the micellization of LDS and clouding of TX-100 in presence of PLH drug have been examined. The conductivity experiments were conducted at temperatures between 288.15 and 323.15 K, with a 5 K interval.The introduction of PLH drug promotes the micelle formation of LDS up to 1 mmol kg−1 of drug. The critical micelle concentration (CMC) values of LDS in aqueous solution of PLH were shifted to lower values in aqueous electrolytes media. The cloud point (CP) of TX-100 + PLH system was observed to be increased with the rise in concentrations of PLH in aqueous medium. The reduction in the CP values of TX-100 and PLH mixed system has been attained with the enrichment of the concentrations of electrolytes and at a specific mole fraction of electrolytes, the CP values exhibited the order: CP (KCl (aq.)) > CP (K2SO4 (aq.)) > CP (K3PO4 (aq.)). The Gibbs free energy of assembly (ΔGm0) appeared as negative (spontaneous assembly) whereas ΔGc0 of clouding showed positive magnitudes indicating the nonspontaneous nature of the clouding process. The micellization of LDS demonstrate the endothermic and exothermic nature at lower and higher investigated temperature as revealed from the sign of ΔHm0values.. The positive values of entrpoyΔSm0 exhibit the micellization process to be entropically driven phenomena. The phase separation of TX-100 and PLH mixed system is entropy contributed in aqueous medium while the clouding in the presence of salts is enthalpy contributed evidenced from the negative enthalpy of clouding.

Investigation of the impacts of several diols on the phase behavior and physico-chemical quantities associated with the Triton X-100 and antidiabetic drug mixture

Drug-surfactant interaction phenomena have received popularity in the pharmaceutical industry and technological sectors from the view point of wider applications. Herein, we aimed to investigate the clouding behavior and various thermodynamic properties of Triton X-100 (TX-100) and metformin hydrochloride drug (MNH; an antidiabetic drug) mixture in the attendance of diols followed by the cloud point measurement technique. The dosage form of metformin hydrochloride drug controls the glucose level in the blood. The different types of diols, i.e., ethylene glycol (EG), 1,2-propylene glycol (1,2-PrG), 2,3-butanediol (2,3-BD), and 1,5-pentanediol (1,5-PD) were uniformly used in this inspection. The effect of diols, with the variation of their concentrations on the clouding behavior of TX-100 + MNH mixture having fixed content of TX-100 (92.7 mmol kg−1) and MNH drug (2 mmol kg−1), were examined. The most enhanced CP value was experienced in the aqueous 1,5-PD medium, whereas the lowest CP value was observed in the aqueous EG medium. The CP values were recorded for the working system under the effect of changing concentrations of diols, which were observed to follow the sequential order: CPH2O+1,5−PD>CPH2O+2,3−BD>CPH2O+1,2−PrG>CPH2O+EG. The clouding progression of the working system was realized to be nonspontaneous as concluded from the positive free energy change (ΔGco) values. The positive and negative values of enthalpy (ΔHco) and entropy (ΔSco) change were documented, respectively, at the low and high concentrations of diols. The hydrophobic interactions amongst different components are predominant at the low concentrations of diols, whereas the electrostatic interactions are leading factors at the high concentrations of diols. Enthalpy-entropy compensation parameters were computed and interpreted with proper perceptive. The outcomes of this observation may be effective and helpful in the various industrial sectors, especially in the drug carrier system in the pharmaceutical arena.

Analytical method for systems of nonlinear singular boundary value problems

The standard Lane–Emden equations model several physical phenomena such as isotropic continuous media, thermal behaviour of a spherical cloud of gas, and isothermal gas spheres. Systems of Lane–Emden-type equations appear in the modelling of the concentration of carbon substrate and oxygen, catalytic diffusion reactions, the steady state concentration of carbon dioxide, dusty fluid models, and pattern formation. In solving singular boundary value problems, one faces challenges resulting from the divergence of the associated variable coefficients at the singular points. This research article explores the power series approach to analytically approximate solutions to a class of systems of strongly nonlinear singular boundary value problems of Lane–Emden-type. The nonlinear terms in the proposed problems are transformed into power series using the generalised Cauchy product before establishing explicit recursion formulae for the expansion coefficients of the system of series solutions. The initial conditions required in the proposed boundary value problems are assumed and determined from a set of nonlinear algebraic equations resulting from the given right boundary conditions. Three special systems of nonlinear singular boundary value problems of Lane–Emden type are presented to demonstrate the proposed method’s reliability, effectiveness, and accuracy. The obtained approximate solutions are compared with the exact solutions (where they are available), or with other existing results (where the exact solution is not readily available). The series solution of the first example has a slow convergent rate, while the results of the other two examples are in excellent agreement with the exact solutions and other published results.

Phase behaviour and thermodynamics of triton X-100 + metformin hydrochloride mixture: influences of several polyols and polymer media

The applications of surfactants and drugs in a wide variety of fields such as pharmaceuticals, food industry, textile, fabrics, etc. are increasing significantly. Herein, we investigated the clouding behavior and thermodynamics of triton X-100 (TX-100) and metformin hydrochloride (MNH) drug mixture in the effect of several polyols and polyethylene glycol (PEG) polymer. The phase separation behavior of the mixture of TX-100 + MNH has been deduced with the help of the cloud point technique. The cloud point (CP) values for the TX-100 and drug mixtures were documented in a decreased and increased manner with the augmentation of the concentration of polyol and PEG respectively. With the subsequent enhancement of polyol and PEG content, the CP values were recorded in the following order: C P H 2 O + PEG > C P H 2 O + fructose > C P H 2 O + glucose > C P H 2 O + galactose > C P H 2 O + maltose . The standard enthalpy change ( Δ H c o ) and entropy change ( Δ S c o ), of TX-100 + MNH mixture in aq. polyols solutions were documented as negative; the negative values reduce in magnitudes with the polyols contents and become positive at the highest polyol content while opposite trend was obtained in presence of PEG. The presence of electrostatic and hydrophobic interactions among TX-100/MNH/polyols/polymer has been recommended as the interaction forces.

Understanding the Influence of the Buoyancy Sign on Buoyancy-Driven Particle Clouds

A numerical model was developed to investigate the behavior of round buoyancy-driven particle clouds in a quiescent ambient. The model was validated by comparing model simulations with prior experimental and numerical results and then applied the model to examine the difference between releases of positively and negatively buoyant particles. The particle cloud model used the entrainment assumption while approximating the flow field induced by the cloud as a Hill’s spherical vortex. The motion of individual particles was resolved using a particle tracking equation that considered the forces acting on them and the induced velocity field. The simulation results showed that clouds with the same initial buoyancy magnitude and particle Reynolds number behaved differently depending on whether the particles were more dense or less dense than the ambient fluid. This was found even for very low initial buoyancy releases, suggesting that the sign of the buoyancy is always important and that, therefore, the Boussinesq assumption is never fully appropriate for such flows.

CFD Turbulence Models Assessment for the Cavitation Phenomenon in a Rectangular Profile Venturi Tube

This study investigates cavitation in a rectangular-profile Venturi tube using numerical simulations and four turbulence models. The unsteady Reynolds-averaged Navier–Stokes technique is employed to simulate vapor cloud formation and compared against experimental data. κ-ε realizable, κ-ε RNG, κ-ω SST, and κ-ω GEKO models are evaluated. The simulation results are analyzed for pressure, turbulence, and vapor cloud formation. Discrepancies in cavitation cloud formation among turbulence models are attributed to turbulence and vapor cloud interactions. RNG and SST models exhibit closer alignment with the experimental data, with RNG showing a superior performance. Key findings include significant vapor cloud shape differences across turbulence models. The RNG model best predicts velocity at the throat exit with an error of 4.145%. Static pressure predictions include an error of 4.47%. The vapor cloud length predictions show variation among models, with the RNG model having a 0.386% error for the minimum length and 4.9845% for the maximum length. The SST model exhibits 4.907% and 13.33% errors for minimum and maximum lengths, respectively. Analysis of the cavitation number reveals agreement with the experimental data and sensitivity to cavitation onset. Different turbulence models yield diverse cloud shapes and detachment points. Weber number contours illustrate the variation in the cavitation cloud behavior under different turbulence models.

Evolution of the cosmic ray spectrum during a Forbush decrease

The Antarctic Cosmic Ray Observatory (ORCA) has been in continuous operation since January 2020 and in nominal phase since March 2021 at the Spanish Antarctic Base Juan Carlos I (Livingston Island, Antarctica 62°39′46′′S,60°23′20′′W at 12 m above sea level) at an effective vertical cutoff rigidity of R=2.37 GV. ORCA consists of two neutron monitors, ORC-A with three BF3 counter tubes following the NM64 standard, and ORC-B, with three bare BF3 counter tubes; and a muon telescope, ORC-M consisting of two 1 m2 scintillators with the neutron monitors between them. ORCA provides neutron count rates at two different energy thresholds (provided by ORC-A and ORC-B) and muon count rates and muon incidence directions throughout the ORCA volume. The neutron-producing cosmic rays observed in ORC-A have a lower rigidity threshold than the muon-producing ones observed in ORC-M. The relationship between them gives an idea about the change in the slope of the cosmic ray spectrum at the corresponding thresholds, 2.37 GV for ORC-A and ≈12 GV for ORC-M. This relation allows to investigate the change in the cosmic ray spectrum along the different regions in an Interplanetary Coronal Mass Ejection, i.e. the shock, the sheath and the magnetic cloud. ORCA first observations are presented, focusing on the analysis of the Forbush Decrease (FD) that happened at the beginning of November 2021. We present these observations and show the promising capabilities of the Antarctic Cosmic Ray Observatory, which represents a new concept of cosmic ray and solar energetic particle detector. The cosmic ray spectrum changes during the Forbush decrease detected in early November 2021 as seen in the change in the ratio of ORC-A to ORC-M count rates. This change is clear after the arrival of the shock and during the magnetic cloud being smoother or even flat in the sheath. In addition, the secondary muons show changes in their arrival directions along the ICME, being clear the different behavior in shock, sheath and magnetic cloud.

Effect of electrolytes on the mechanism of clouding process and physico-chemical quantities of non-ionic surfactant and ciprofloxacin hydrochloride mixture

An investigation of the clouding behaviour of the aqueous solution of ciprofloxacin hydrochloride (CIPH) + Triton X-100 (TX-100) under different electrolytes media was performed by the phase-changing measurement method. The CP of the resultant mixture has been studied in aqueous solutions of some organic and inorganic salts (sodium carbonate (Na2CO3), sodium oxalate (NaOxa), sodium acetate (NaOAc) and magnesium sulphate (MgSO4)). The CP values of TX-100 (50 mmol kg−1) + CIPH (1 mmol kg−1) solution decreases in the presence of all electrolytes while the CP values satisfy the sequence: CP (aq. NaOAc) > CP (aq. MgSO4) > CP (aq. Na2CO3) > CP (aq. NaOxa). The decrease in the solubility of employed solution in the aq. electrolytes media was observed and obtained maximum solubility in aqueous NaOAc and minimum solubility in the aqueous NaOXa medium. The obtained positive Gibbs-free energy ( Δ G c 0 ) demonstrates the nonspontaneous nature of phase separation while the extent of nonspontaneity exhibits the reduction with enhancing electrolyte concentrations. The Δ H c 0 and Δ S c 0 values depict the existences of electrostatic and hydrophobic interactions between TX-100 and CIPH in aq. electrolytes solutions and the clouding process is enthalpy controlled. Entropy-enthalpy compensation variables were computed.

High-substituted hydroxypropyl cellulose prepared by homogeneous method and its clouding and self-assembly behaviors

Hydroxypropyl cellulose (HPC) is a sustainable cellulose derivative valued for its excellent biocompatibility and solubility and is widely used in various fields. Recent scientific research on high-substituted HPC mainly focused on its efficient preparation and phase transition behavior. Herein, a novel strategy of high-substituted HPC synthesis was demonstrated by employing DMSO/TBAF·3H2O as a cellulose solvent, exhibiting more efficiency than traditional approaches. High-substituted HPC prepared has remarkable thermal stability, exceptional hydrophilicity, and satisfactory solubility. Phase transition behavior of HPC with varying molar degrees of substitution (MS) was delved and a notable negative correlation between MS and cloud point temperature (TCP), was revealed, particularly evident at an MS of 12.3, where the TCP drops to 33 °C. Moreover, a unique self-assembly behavior featuring structural color and responsiveness to force in a solvent-free environment emerged when the MS exceeded 10.4. These insights comprehensively strengthen the understanding and knowledge of high-substituted HPC, simultaneously paving the way for further HPC investigation and exploitation.

Secondary droplet activation during condensational growth in convective clouds and its detection from satellites

By acting as cloud condensation nuclei (CCN), aerosol particles play a key role in the climate system. The CCN can be activated into cloud droplets at the cloud base (i.e., primary activation), or above it (i.e., secondary activation). This study shows the conditions required for secondary activation during the condensational growth phase in convective clouds. It also proposes a methodology for detecting this secondary activation from satellites. Using a spectral bin adiabatic parcel model, we simulate the vertical profile of cloud microphysical properties and demonstrate how different aerosol size distributions and updraft velocities greatly affect the secondary activation initiation and the cloud properties. The secondary activation slows down the cloud drop effective radius (re) growth rate with increasing height, and decreasing temperature (T), due to the relatively larger population of smaller droplets in the cloud parcel. Therefore, the vertical profile of re growth with height is slower than the adiabatic rate when the secondary activation occurs.The proposed physical principle was verified by satellite-retrieved T-re profiles and adiabatic cloud drop number concentrations (Nd) over the Amazon region. The results obtained from this study can be utilized to identify the secondary droplet activation during the condensational growth phase, which can lead to an overestimation of the retrieved Nd as well as suppression of warm rain. This improves our knowledge and observational capabilities of the role of aerosol particles in the microphysics, dynamics, and precipitation behavior of convective clouds. Plain text summarySmall particles serve as sites for cloud droplets' condensation at the cloud base (primary droplet activation) or above it (secondary activation). Once a droplet is activated at the cloud base, the surrounding water vapor condenses on it and the droplet grows - this is called condensational growth. The cloud droplet number concentrations (Nd) can be obtained by the satellite-retrieved vertical growth rate of droplet size in the condensational growth phase. However, new small droplets formed during this phase (i.e., secondary activation), might cause an overestimate in the retrieved Nd. This study presents the physical principle of secondary activation during condensational growth. Using a model, we simulate the condensational growth of aerosol particles, which act as cloud condensation nuclei (CCN), for different particle size distributions and thermodynamic conditions (i.e., vertical velocities). Our simulations show that secondary activation slows the cloud droplet growth rate with height due to the larger competition for the available water vapor promoted by the new drops. Comparisons between satellite-retrieved Nd of convective clouds and in-situ measurements show that the satellite retrievals overestimate Nd when the secondary activation of droplets is neglected. Our findings improve the understanding of aerosols' role in the condensational growth of droplets in convective clouds.

Study of Cloud Liquid Water Content Over Iraq Through Heavy Rain Cases

Because of heavy rains and drought, Iraq’s water resources have been catastrophically depleted. In this study, we relied on four cities distributed in Iraq. The date of this study where the floods occurred is January 27-28 2019. Torrential rains cause great dangers to lives, agriculture, and water resources, as happened in the history of this study. These risks can be avoided by knowing more accurately the behavior of the cloud. The basic building block for knowing cloud behavior is knowing the behavior of the liquid water content cloud (CLWC). Through it, we addressed the issue of the characteristics of the CLWC, its variation with time and space, and its vertical distribution within the cloud over Iraq, affected by the synoptic low-pressure system. Through this study, they noticed a significant difference in the behavior of CLWC in the different cities of Iraq. We also determined the nature of the relationship between CLWC and relative humidity, air temperature, and precipitation. Data used in the study are taken from ERA5 | ECMWF, and the General Authority for Meteorology and Seismic Monitoring).

Privacy-Preserving Outsourcing of K-Means Clustering for Cloud-Device Collaborative Computing in Space-Air-Ground Integrated IoT

Facing the explosive growth of data, the introduction of cloud computing in the space-air-ground integrated Internet of things (SAGIIoT) can solve the problem of limited computing power of the terminals. At the same time, data security on the cloud is also a focus that cannot be ignored. Secure outsourcing computing is helpful in improving privacy-preserving. Due to the wide applicability of K-means clustering, outsourcing computing for K-means has become a major research hotspot in industry and academia. Most of the existing work on outsourcing K-means clustering is based on homomorphic encryption, which has a high computational overhead due to the mathematical puzzles’ nature of homomorphic encryption. In addition, the high computational overhead of designing a verification algorithm based on homomorphic encryption is unacceptable. To address the above issues, we design a K-means clustering outsourcing algorithm by sparse matrix transformation, which can verify the deceptive behavior of cloud while achieving high efficiency. In this paper, we theoretically prove the accuracy, security, efficiency and verifiability of the proposed algorithm. Extensive experiments indicate that our algorithm is efficient.

Bubble cloud characteristics and ablation efficiency in dual-frequency intrinsic threshold histotripsy

Histotripsy is a non-thermal focused ultrasound ablation method that destroys tissue through the generation and activity of acoustic cavitation bubble clouds. Intrinsic threshold histotripsy uses single-cycle pulses to generate bubble clouds when the dominant negative pressure phase exceeds an intrinsic threshold of ∼25–30 MPa. The ablation efficiency is dependent upon the size and density of bubbles within the bubble cloud. This work investigates the effects of dual-frequency pulsing schemes on the bubble cloud behavior and ablation efficiency in intrinsic threshold histotripsy. A modular 500 kHz:3 MHz histotripsy transducer treated agarose phantoms using dual-frequency histotripsy pulses with a 1:1 pressure ratio from 500 kHz and 3 MHz frequency elements and varying arrival times for the 3 MHz pulse relative to the arrival of the 500 kHz pulse (−100 ns, 0 ns, and +100 ns). High-speed optical imaging captured cavitation effects to characterize bubble cloud and individual bubble dynamics. The effects of dual-frequency pulsing on lesion formation and ablation efficiency were also investigated in red blood cell (RBC) phantoms. Results showed that the single bubble and bubble cloud size for dual-frequency cases were intermediate to published results for the component single-frequencies of 500 kHz and 3 MHz. Additionally, bubble cloud size and dynamics were shown to be altered by the arrival time of the 3 MHz pulse with respect to the 500 kHz pulse, with more uniform cloud expansion and collapse observed for early (−100 ns) arrival. Finally, RBC phantom experiments showed that dual-frequency exposures were capable of generating precise lesions with smaller areas and higher ablation efficiencies than previously published results for 500 kHz or 3 MHz. Overall, results demonstrate dual-frequency histotripsy’s ability to modulate bubble cloud size and dynamics can be leveraged to produce precise lesions at higher ablation efficiencies than previously observed for single-frequency pulsing.

Fault Tolerance of Cloud Infrastructure with Machine Learning

Abstract Enhancing the fault tolerance of cloud systems and accurately forecasting cloud performance are pivotal concerns in cloud computing research. This research addresses critical concerns in cloud computing by enhancing fault tolerance and forecasting cloud performance using machine learning models. Leveraging the Google trace dataset with 10000 cloud environment records encompassing diverse metrics, we systematically have employed machine learning algorithms, including linear regression, decision trees, and gradient boosting, to construct predictive models. These models have outperformed baseline methods, with C5.0 and XGBoost showing exceptional accuracy, precision, and reliability in forecasting cloud behavior. Feature importance analysis has identified the ten most influential factors affecting cloud system performance. This work significantly advances cloud optimization and reliability, enabling proactive monitoring, early performance issue detection, and improved fault tolerance. Future research can further refine these predictive models, enhancing cloud resource management and ultimately improving service delivery in cloud computing.

CTAB induced growth and shrinkage of Pluronics® P103 micelles: Experimental and theoretical rationale

This study offers an insight into the concentration influence of a cationic surfactant- cetyltrimethylammonium bromide (CTAB) having a 16-carbon long alkyl side chain that influences the self-assembly and micellization behaviour of a linear triblock copolymer based on ethylene oxide (EO) and propylene oxide (PO) Pluronic® P103 in aqueous solution. The work makes an exclusive use of a variety of methodologies, such as high sensitivity differential scanning calorimetry (HSDSC), phase behaviour study, dynamic light scattering (DLS), and small-angle neutron scattering (SANS). The investigation on the clouding behaviour demonstrates that the cloud point value of 5 %w/v P103, which is typically in the vicinity of 90 °C, rises up to more than 100 °C with the addition on of very low concentration of CTAB. The DLS technique predicted the change in hydrodynamic diameter (Dh) of micelles with temperature and in varying CTAB concentration. The SANS results inferred the morphological changes in the micelles. A comprehensive approach revealing the relationship between the molecular orbital energies of the tested P103 and CTAB were assessed by utilising the computational simulation method with the Gaussian 09 calculation window and Gauss View 5.0.9 software. The perception of CTAB-stabilized Pluronics® micelles is predicted to be much improved from the evaluated optimised descriptors. Additionally, our examined micellar system revealed the solubilization enhancement of a model hydrophobic dye orange-OT utilizing UV–vis spectroscopy.

Clouding of TX-100 and promethazine hydrochloride mixture: Impacts of Na salts on the physicochemical parameters and interaction forces linked with studied components

Interest in the phase separation behaviors and interactions between non-ionic surfactants and various drug species in aqueous salt solutions have grown significantly in recent years due to their extensive applications in industry and medicine. This study explored the clouding characteristics of a triton X-100 (TX-100) and promethazine hydrochloride (PMH) mixture in various aqueous sodium salt (such as NaOAc, NaOxal, Na2CO3, NaHCO3, and NaNO3) solutions. The physicochemical variables and interaction forces between TX-100 and PMH species in different sodium salt media were successfully determined by measuring the cloud point (CP). Different electrolyte solutions have been found to alter the clouding behavior of TX-100 + PMH. The CP magnitudes for TX-100 + PMH combinations decreased as the Na salt concentrations were increased, and the respective CPs decreased in the order: Na2CO3 > NaOxal > NaHCO3 > NaOAc > NaNO3. The salting-out effect played a significant role in decreased CP, possibly due to the reduction in water solubility of solutes in the presence of other soluble ions within the mixtures. The ΔGc0 of TX-100 and the employed drug mixture in aqueous salt media was positive, demonstrating the non-spontaneous nature of the clouding process. However, the non-spontaneity of phase separation in the corresponding mixtures decreased as the electrolyte content of the solution increased. The ΔHc0 and ΔSc0 were negative, suggesting that the clouding progression in the studied mixtures was exothermic and driven by enthalpy change. The evaluation of the intrinsic enthalpy gain (ΔHco,∗) and the compensation temperature (Tc) provided evidence of the interactions between TX-100 and PMH species. This research is significant and may be useful in different industries, including for formulating various drugs in the pharmaceutical industry.

Rockfalls, fragmentation, and dust clouds: analysis of the 2017 Pousset event (Northern Italy)

The process and dynamics of rock fragmentation during the collapse of rockfalls and rock avalanches is a poorly developed topic. The most severe fragmentation often leads to the formation of a rock dust that rises to form a cloud suspended in the air. The understanding of fragmentation processes is hampered by the environmental disturbances that alter the dust cloud deposit shortly after deposition. Here, we study the fragmentation of the October 2017 Pousset rockfall, detached from a NNE facing steep bedrock wall in the permafrost zone, that involved 8,300m3 of metamorphic rock and fell about 800 m. The collapse generated large boulders which rolled downslope and a thick and large dust cloud. The source and deposit were investigated, and dust cloud material was sampled at different locations to reconstruct an exponential thickness distribution and perform grain size characterization. The fragmentation energy was estimated by integrating the spectrum of the grains assuming that the fragmentation energy is proportional to the generated area. The fragmentation energy was found to be about 0.4% of the initial potential energy. Most probable fragmentation points and block deposition areas were evaluated and positioned by means of the HyStone 3D rockfall simulator. Furthermore, we calculated the flow rate of the suspended powder generated by the fragmentation process and compared the results with observations available for the evolution of the phenomenon and the collected samples. The Pousset event, in its relatively simple dynamics, may be a good testing ground to address the current theories of rockfall and rock avalanche fragmentation and dust cloud behavior.