4,639 results on '"surfactant"'
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2. The voltammetric determination and electrochemical mechanism of alpha-lipoic acid at a multi-walled carbon nanotube-surfactant modified glassy carbon electrode in the food additive sample.
- Author
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Yardım, Dilek Özcan and Pınar, Pınar Talay
- Abstract
Alpha-lipoic acid (α-LA) is a naturally occurring compound that is both water and fat soluble, functioning as a powerful antioxidant in the body. In this study, multi-walled carbon nanotubes (MWCNTs) with SDS were electrodeposited onto a glassy carbon electrode (GCE) electrochemically. This modified electrode was characterized by electrochemical techniques (EIS, CV). The MWCNT/SDS-modified GCE was utilized for the analysis of α-LA. An electrochemical oxidation mechanism for α-LA was proposed using the developed electrochemical sensor. After optimizing the conditions, the MWCNT/SDS-GCE sensor exhibited a linear response in the concentration range of 0.6–9.0 µM, with a detection limit of 0.15 µM. Additionally, this chemical sensor was effectively utilized for the electrochemical analysis of α-LA in the food additive sample. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Development of Bifunctional Electrospun Filters Incorporating Surfactants for Enhanced Particulate Matter Filtration and Antimicrobial Activity.
- Author
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da Silva, Edilton Nunes, Chagas, Paulo Augusto Marques, de Aquino Lima, Felipe, de Souza, Clovis Wesley Oliveira, Aguiar, Mônica Lopes, and Guerra, Vádila Giovana
- Abstract
Ultrafine particulate matter and airborne microorganisms present in the atmosphere significantly affect human health, leading to serious respiratory diseases. Among these particulates are bioaerosols, which include viruses, bacteria, and fungi. When inhaled, these microorganisms can cause diseases, such as influenza, tuberculosis, and COVID-19. Therefore, the development of bifunctional membranes that can simultaneously filter particulate matter (PM) and inhibit microorganism growth is essential. Electrospun filters, known for their high surface area, are effective in capturing these airborne particles. This study presents a novel approach by incorporating various surfactants into electrospun filters made from 8% polyacrylonitrile (PAN). The surfactants used include cetyltrimethylammonium bromide (CTAB), widely cited in the literature for bactericidal filtering applications, as well as sodium dodecyl sulfate (SDS) and cetylpyridinium chloride (CPC), which are rarely used in electrospun filters for this purpose. The addition of surfactants enhanced the filter performance, capturing particles smaller than 250 nm with over 99% efficiency for particles between 6.38 and 242 nm. The pressure drop across the filters ranged from 111.4 ± 1.2 to 204.4 ± 1.1 Pa. Moreover, the incorporation of surfactants not only improved hydrophobic and hydrophilic properties—where hydrophobic nanofibers performed better for filtration—but also significantly increased antimicrobial activity against Staphylococcus aureus (97.25 ± 0.95%) and Escherichia coli (94.52 ± 2.37%). These filters not only capture particles but also inactivate pathogens, contributing to a healthier environment. Filters with biocidal properties are particularly useful in hospitals, laboratories, and other settings where air sterility is critical. [ABSTRACT FROM AUTHOR]
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- 2024
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4. New piperidinium surfactants with carbamate fragments as effective adjuvants in insecticide compositions based on imidacloprid.
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Kushnazarova, Rushana A., Mirgorodskaya, Alla B., Vasilieva, Elmira A., Lenina, Oksana A., Petrov, Konstantin A., and Zakharova, Lucia Ya.
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CATIONIC surfactants ,GREENHOUSE whitefly ,ORNAMENTAL plants ,INSECT pests ,DISPERSING agents ,IMIDACLOPRID - Abstract
BACKGROUND: Surfactants, particularly non‐ionic ones, are widely used as adjuvants in pesticide formulations due to their ability to maintain pesticide effectiveness without changing solution properties, such as pH. While non‐ionic surfactants are generally low‐toxic, stable, and excellent dispersants with high solubilization capabilities, they may be less effective than cationic surfactants, which offer superior surface activity, transport properties, and antimicrobial action. This study investigates the efficacy of new piperidinium surfactants with carbamate fragments as adjuvants in insecticide formulations containing imidacloprid. The efficacy of these formulations is being assessed against greenhouse whitefly, a pest known to harm cultivated and ornamental flowering plants. RESULTS: The aggregation behavior of piperidinium surfactants containing carbamate fragments was investigated, and their wetting effect was evaluated. Synthesized surfactants have lower CMC values compared to their methylpiperidinium analogue. The effect of piperidinium surfactants on the insecticide concentration on the surface and inside tomato leaves was assessed using spectrophotometric methods. It was found that the introduction of piperidinium surfactants with carbamate fragment at a concentration of 0.1% wt. allows for decrease in lethal concentration of imidacloprid up to 10 times, thereby testifying the marked increase in the effectiveness of imidacloprid against the greenhouse whitefly insect pest (Trialeurodes vaporariorum). It was shown that the main factors responsible for the enhanced efficacy of the insecticide were the ability of the surfactant to increase the concentration of imidacloprid on the leaf surfaces and improve their penetration into the plant. CONCLUSION: The presented work employed a comprehensive approach, which significantly increases the generalizability of the results obtained and provides the ability to predict the effect and target selection of adjuvants. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Formulation and characterization of nanoemulsions stabilized by nonionic surfactant and their application in enhanced oil recovery.
- Author
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Goswami, Anindya Sundar, Rawat, Rajvardhan, Pillai, Prathibha, Saw, Rohit Kumar, Joshi, Dinesh, and Mandal, Ajay
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ENHANCED oil recovery ,NONIONIC surfactants ,INTERFACIAL tension ,PETROLEUM ,ZETA potential - Abstract
Nanoemulsions are kinetically stable emulsions with droplet size distribution in the range of 10–500 nm. Low interfacial tension (IFT), small droplet size, and wettability alteration properties of nanoemulsions have led to their application for enhanced oil recovery (EOR) EOR. The current study deals with the formulation and characterization of Tergitol 15-S-9 surfactant stabilized oil/water nanoemulsion (NE). Optimal surfactant concentration accompanied by optimal salinity determination was done by observing long-term stability. The stability of the nanoemulsions was analyzed by Turbiscan and Zeta potential analysis. The optimal nanoemulsion was characterized in terms of droplet size, rheology, wettability, miscibility, and IFT. All the prepared nanoemulsion showed particle size < 300 nm. optimized nano emulsion, that is, 0.5 wt.% surfactant +0.5 wt.% salinity showed good IFT reduction and wettability alteration capability. Nanoemulsion also showed good miscibility behavior with actual crude oil at 60 °C. Rheology of the formed emulsion shows a mixed nature that is shear thinning as well as shear thickening nature which is favorable for heterogeneous reservoirs. Core-flooding experiments were conducted at optimized nanoemulsion formulation, and additional oil recovery of 13.93% of the original oil in place was obtained after the conventional water flooding. Highlights: Experimental and mechanistic investigation of nanoemulsions for oil recovery. Enhanced miscibility of Tergitol 15-S-9 stabilized nanoemulsion with crude oil. Viscosity enhancement by macromolecular and supramolecular network structures. Low IFT achieved for the nanoemulsion resulting enhanced oil displacement. Encouraging oil displacement by injection of formulated nanoemulsion. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Risk factors for refractory respiratory distress syndrome among very-low-birth-weight infants.
- Author
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Shin, Jeongmin, Choi, Chang Won, and Lee, Byung Kook
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RESPIRATORY distress syndrome ,LOGISTIC regression analysis ,VERY low birth weight ,CESAREAN section ,NEONATAL mortality - Abstract
Background: The objective was to evaluate refractory respiratory distress syndrome (RDS) risk factors among very-low-birth-weight infants (VLBWIs). Method: The data of VLBWIs born between January 2013 and December 2020 registered in the Korean Neonatal Network (KNN) were analyzed. Infants who died within 5 postnatal days or who were not given surfactant were excluded. Infants were divided into a well-responding RDS group, which received surfactant replacement therapy (SRT) only once, and a refractory RDS group, which received SRT twice or more. The associations between perinatal characteristics and refractory RDS were investigated via multivariate logistic regression analysis. Results: Multivariate logistic regression analysis revealed that low gestational age (adjusted odds ratio [aOR] = 1.26, 95% confidence interval (CI) [1.23, 1.26], male sex (aOR = 1.17, 95% CI [1.06, 1.29]), cesarean section (aOR = 1.59, 95% CI [1.38, 1.80]), maternal hypertensive disorder (aOR = 1.54, 95% CI[1.35, 1.75]), and low 5-minute Apgar scores (aOR = 1.24, 95% CI [1.12, 1.37]) were significantly associated with refractory RDS. Antenatal corticosteroid use (aOR = 0.81, 95% CI [0.73, 0.89]) and maternal chorioamnionitis (aOR = 0.79, 95% CI [0.71, 0.88]) were significantly inversely associated with refractory RDS. Compared with well-responding RDS, refractory RDS was significantly associated with increased major neonatal morbidity and mortality risk at 5 postnatal days. Conclusion: Maternal hypertensive disorder is a significant risk factor for refractory RDS. Refractory RDS was associated with unfavorable neonatal outcomes. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Effect of different CPAP levels on ultrasound-assessed lung aeration and gas exchange in neonates.
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Sartorius, Victor, Loi, Barbara, Vivalda, Laura, Regiroli, Giulia, De La Rubia-Ortega, Sofia, Pezza, Lucilla, Midevaine, Manon, Shankar-Aguilera, Shivani, Ben-Ammar, Rafik, and De Luca, Daniele
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CONTINUOUS positive airway pressure ,RESPIRATORY distress syndrome ,LUNGS ,OXYGEN in the blood ,NEWBORN infants - Abstract
Background: Respiratory distress syndrome (RDS) and transient tachypnoea (TTN) are the two commonest neonatal respiratory disorders. The optimal continuous positive airway pressure (CPAP) to treat them is unknown. We aim to clarify the effect of different CPAP levels on lung aeration and gas exchange in patients with RDS and TTN. Methods: Prospective, observational, pragmatic, physiological cohort study. CPAP was sequentially increased from 4 to 6 and 8 cmH
2 O and backwards, with interposed wash-out periods. Lung aeration was assessed with a validated neonatal lung ultrasound score. Gas exchange was non-invasively evaluated with transcutaneous monitoring. Ultrasound score and PtcO2 /FiO2 ratio were the co-primary outcomes. PtcCO2 and other oxygenation metrics were the secondary outcomes. Results: 30 neonates with RDS and 30 with TTN were studied. Each CPAP increment significantly (overall always p < 0.001) improved both lung aeration and oxygenation, but the increase from 6 to 8 cmH2 O achieved a small absolute benefit. In RDS patients, the absolute improvements were small and the diagnosis of TTN was significantly associated with greater improvement of lung aeration (β= -1.4 (95%CI: -2.4; -0.3), p = 0.01) and oxygenation (β = 39.6 (95%CI: 4.1; 75.1), p = 0.029). Aeration improved in 16 (53.3%) and 27 (90%) patients in the RDS and TTN groups, respectively (p = 0.034). Lung aeration showed significant hysteresis in TTN patients. Secondary outcomes gave similar results. Conclusions: Increasing CPAP from 4 to 8 cmH2 O improves ultrasound-assessed lung aeration and oxygenation in RDS and TTN. The absolute improvements are small when CPAP is beyond 6 cmH2 O or for RDS patients. [ABSTRACT FROM AUTHOR]- Published
- 2024
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8. Gas Flow Blockage Treatment in Shale Gas: Case Study of Qusaiba Hot Shale, Saudi Arabia.
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AlQuraishi, Abdulrahman A., AlMansour, Abdullah O., AlAwfi, Khalid A., Alonaizi, Faisal A., AlYami, Hamdan Q., and Ali, Ali M. AlGhamdi
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SOLUTION (Chemistry) ,CONTACT angle ,CRITICAL micelle concentration ,OIL shales ,PRESSURE drop (Fluid dynamics) - Abstract
Organic-rich hot Qusaiba shale is the primary source rock of most of the Paleozoic hydrocarbon reservoirs of eastern and central Arabia. Representative near-surface Qusaiba shale samples were collected and characterized from one of its outcrop sections at the Tayma quadrangle in northwest Saudi Arabia. The petrophysical and geochemical characterization indicated porosity and permeability of 8.2% and 2.05 nD, respectively, with good total organic carbon (TOC) of 2.2 mg/g and mature kerogen of gas-prone type III. The tight characteristics of the formation can lead to high capillary pressure and extensive post-fracking water retention, leading to flow blockage and a reduction in gas productivity. Three different surfactants and one ionic liquid, namely, Triton X-100, Triton X-405 and Zonyle FSO surfactants and Ammoeng 102 ionic liquid, were tested as additives to fracking fluid to investigate their effectiveness in optimizing its performance. The chemical solutions exhibited no sign of instability when exposed to solution salinity and temperatures up to 70 °C. The investigated chemicals' performance was examined by measuring methane/chemical solutions' surface tension and their ability to alter shale's wettability. The results indicate that Zonyl FSO is the most effective chemical, as it is able to significantly reduce surface tension and, hence, capillary pressure by 66% when added at critical micelle concentration (CMC). Using Zonyl FSO surfactant at a maximum tested concentration of 0.2% induced a relatively smaller capillary pressure drop (54%) due to the drastic drop in the contact angle rendering shale very strongly water-wet. Such a drop in capillary pressure can lower the fracking fluid invasion depth and therefore ease the liquid blockage removal during the flowback stage, enhancing gas recovery during the extended production stage. Triton X-100 at CMC was the second most effective surfactant and was able to induce a quite significant 47% drop in capillary pressure when added at the maximum tested concentration of 0.05%. This was sufficient to remove any liquid blockage but was less likely to alter the wettability of the shale. Based on the findings obtained, it is suggested to reduce the blockage tendency during the fracking process and elevate any existing blockage during the flowback stage by using Zonyl FSO at CMC where IFT is at its minimum with a higher contact angle. [ABSTRACT FROM AUTHOR]
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- 2024
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9. Evaluation of Lignocellulatic Activity of Enzymes from Microwave-irradiated Pleurotus sajor-caju Cultivated with Wheat Straw.
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Al-Rajhi, Aisha M. H., Bazaid, Abdulrahman S., Abdulfattah, Ahmed M., Abdelghany, T. M., Shater, Abdel-Rahman M., and Selim, Samy
- Abstract
The production of lignocellulytic enzymes by microwave-radiated Pleurotus sajor-caju was assayed. Wheat straw was employed as substrate to P. sajor-caju for production of laccase, manganese peroxidase (MnPase), filter-paperase (FPase), carboxmethyl cellulase (CMCase), and cellulase (as evaluated using microcrystalline cellulose). P. sajor-caju exposed to 10 s of microwave radiation (MR) showed maximum growth with colony radius of 7.17 ± 0.45 cm, while with increasing the exposure time up to 50 s the growth decreased up to 2.67 ± 0.22 cm. Moreover, it failed to grow at 80 s of exposure time. Cellulase, MnPase, FPase, CMCase, and laccase activities were induced to 37 ± .0.54, 49 ± 2.36, 189 ± 2.12, 0.37 ± 0.06, and 1.58 ± 0.03 U/mL compared to that at control 31 ± 0.25, 46 ± 1.25, 177 ± 1.65, 0.28 ± 0.03, and 1.37 ± 0.12 U/mL, respectively as a result of P. sajor-caju exposure to 10 s of MR. As the exposure time increased, these enzymes activity decreased. Different levels of moisture with surfactant (polysorbate 80) were applied to optimize the enzymes activities at 10 s of exposure time. The optimum activities 3.15 ± 0.23, 0.62 ± 0.06, 269 ± 5.36, 65 ± 1.63, and 48 ± 0.98 U/mL were recorded for cellulase, MnPase, FPase, CMCase, and laccase, respectively at 70% of moisture and 0.15 mL/L of polysorbate 80. [ABSTRACT FROM AUTHOR]
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- 2024
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10. Polyaniline/carbon nanotube composite materials prepared by soft template of double surfactants for supercapacitors.
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LIANG Huabin, HE Mingji, ZHONG Xinxian, YANG Zhibin, LIANG Shihong, LI Qingyu, and LIANG Min
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In this paper, PANI/CNTs composite materials were prepared by emulsion polymerization with sodium dodecyl benzene sulfonate (SDBS) and Tween-80 (Tween-80) as soft templates, ammonium persulfate (APS) as oxidant, and carbon nanotubes (CNTs) mixed with appropriate amount. The composite materials were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The results show that PANI/CNTs composites present core-shell structure with fiber shape, and PANI materials cover the surface of CNTs uniformly. The electrochemical test results show that the specific capacitance of PANI/CNTs electrode is 478.48 F/g at the current density of 1.0 A/g. After 1 000 cycles, the specific capacitance retention rate of PANI/CNTs is 70.01%, while that of PANI prepared by traditional method is only 49.10%. The specific capacitance of PANI/CNTs composites obtained by emulsion polymerization is higher than that of PANI single material obtained by traditional method, and the cycle life is significantly improved. This method provides an important strategy for the preparation of electrode materials of high-performance supercapacitors. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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11. Surfactant Phospholipid Kinetics in Ventilated Children after Therapeutic Surfactant Supplementation.
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Goss, Victoria M., Dushianthan, Ahilanandan, McCorkell, Jenni, Morton, Katy, Goss, Kevin C. W., Marsh, Michael J., Pappachan, John V., and Postle, Anthony D.
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CHILD patients ,PEDIATRIC intensive care ,RADIOLABELING ,ARTIFICIAL respiration ,STABLE isotopes - Abstract
Acute lung Injury leads to alterations in surfactant lipid composition and metabolism. Although several mechanisms contribute to dysregulated surfactant metabolism, studies investigating in vivo surfactant metabolism are limited. The aim of this study is to characterise surfactant phospholipid composition and flux utilising a stable isotope labelling technique in mechanically ventilated paediatric patients. Paediatric patients (<16 years of age) received 3.6 mg/kg intravenous methyl-D
9 -choline chloride followed by the endotracheal instillation of 100 mg/kg of exogenous surfactant after 24 h. Bronchioalveolar fluid samples were taken at baseline and 12, 24, 36, 48, 72 and 96 h after methyl-D9 -choline infusion. Nine participants (median age of 48 days) were recruited. The primary phosphatidylcholine (PC) composition consisted of PC16:0/16:0 or DPPC (32.0 ± 4.5%). Surfactant supplementation resulted in a 30% increase in DPPC. Methyl-D9 PC enrichment was detected after 12 h and differed significantly between patients, suggesting variability in surfactant synthesis/secretion by the CDP-choline pathway. Peak enrichment was achieved (0.94 ± 0.15% of total PC) at 24 h after methyl-D9 -choline infusion. There was a trend towards reduced enrichment with the duration of mechanical ventilation prior to study recruitment; however, this was not statistically significant (p = 0.19). In this study, we demonstrated the fractional molecular composition and turnover of surfactant phospholipids, which was highly variable between patients. [ABSTRACT FROM AUTHOR]- Published
- 2024
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12. Surfactant-Assisted Regulation of WS 2 /Tourmaline Microstructures for Excellent Photocatalytic Performance.
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Wang, Xianku, Cui, Kaibin, Zhao, Yuqin, Hao, Ming, Bian, Liang, Wang, Mingming, and Wang, Fei
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RHODAMINE B ,PHOTOCATALYSTS ,TOURMALINE ,OPTICAL properties ,PHOTOCATALYSIS - Abstract
The controllable electrical and optical properties of two-dimensional tungsten disulfide (WS
2 ) attracted much attention in photocatalysis, but commercial development has been severely restricted by their restacking properties. Surfactant-assisted synthesis techniques can be considered as an effective option to break this bottleneck. In this work, the effect of surfactants including sodium dodecylbenzene sulfonate (SDBS), hexadecyltrimethylammonium bromide (CTAB), and polyvinylpyrrolidone (PVP) on the microstructure of WS2 /tourmaline composites prepared by coupled hydrothermal and calcination methods was explored. The WS2 nanosheets were uniformly deposited on the tourmaline surface with the assistance of 1.0 mmol/L SDBS. Meanwhile, WS2 /Tour-SDBS exhibited the highest rhodamine B (RhB) degradation activity, which was 1.8 and 2.3 times higher than that of photocatalysts prepared with CTAB and PVP under the same conditions, respectively. This study provides a new tactic for the fabrication of high-performance WS2 -based composites. [ABSTRACT FROM AUTHOR]- Published
- 2024
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13. On the stochastic Cahn-Hilliard-Navier-Stokes systems with surfactant.
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Medjo, Theodore Tachim
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STOCHASTIC systems ,NAVIER-Stokes equations ,NEUMANN boundary conditions ,PARTIAL differential equations ,SURFACE active agents ,CLASSICAL solutions (Mathematics) ,CAHN-Hilliard-Cook equation - Abstract
We consider the stochastic Cahn-Hilliard-Navier-Stokes with surfactant on a bounded domain, driven by a multiplicative noise. The resulting system of partial differential equations consists of a Navier-Stokes systems for the (average) velocity, a sixth-order Cahn–Hilliard equation for the difference of local concentrations of the binary fluid mixture coupled with a fourth–order Cahn-Hilliard equation for the local concentration of the surfactant. The former has a smooth potential, while the latter has a singular potential. Both equations are coupled with a Navier-Stokes system with a multiplicative noise of Gaussian type for the (volume averaged) fluid velocity. The evolution system is endowed with suitable initial conditions, a no-slip boundary condition for the velocity field and homogeneous Neumann boundary conditions for the phase functions as well as for the chemical potentials. The existence of a global weak martingale solution is proved under non-Lipschitz assumptions on the coefficients in both two and three dimensional bounded domains. In the two dimensional case and when the viscosity of the mixture is assumed to be constant, we prove the pathwise uniqueness of the weak solution, and using the Yamada-Watanabe classical result to derive the existence of a strong solution (in probabilistic sense). [ABSTRACT FROM AUTHOR]
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- 2024
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14. Effect of Electrokinetic Leaching with Surfactant on Desorption of Semi-Volatile Organic Pollutants in Soil.
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Guo, Yingda, Li, Gang, Xiao, Zhiying, Li, Fengmei, Cheng, Fenglian, Zhao, Ze, and Guo, Shuhai
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ORGANIC soil pollutants ,NONIONIC surfactants ,SODIUM dodecyl sulfate ,PLASTICS ,SOIL pollution - Abstract
Semi-volatile organic pollutants were found in most organic contaminated sites, especially in the industrial production of plastic and paint products, dismantling of electronic wastes, production of organic solvents, and chemical coatings. Electrokinetic remediation (EKR) was recognized as critical method to resolve the problem of organic pollutants separation and degradation. However, the low efficiency desorption and migration of organic pollutants was the main concerns during EK remediation. In this study, cyclododecane (CDD) was selected to investigate the process of electroosmotic flushing with anionic surfactant (sodium dodecyl sulfate, SDBS) and non-ionic surfactants (alcohol ethoxylate, AEO) for facilitating chemical desorption of low boiling point organic pollutants from soil. Simulated contaminated soil was subjected to treatment in an EK cell at 1 V/cm for 7 days. The experimental dependent variables, such as current, electroosmotic flow (EOF), pH, electrical conductivity (EC), and the concentration of CDD in the contaminated soil were continuously monitored. The results revealed that both current and EOF exhibited the trend of SDBS (13.74 mA, 350.9 mL) > water (8.22 mA, 285.7 mL) > AEO (6.12 mA, 124.3 mL). Furthermore, the removal efficiency of CDD by surfactants also followed this order with corresponding percentages of 90.87% and 90.01%. The soil pH near the cathode increased, and it caused alkalization trend of the flowing soil solution and improvement of CDD removal rate. Conversely, the lowest EC value was observed in the middle of the soil chamber. The highest overall CDD removal rate was achieved by employing a strategy of surfactant-assisted electrokinetic remediation, and approximately 90% CDD was transfered to the liquid phase. These findings contribute to our understanding of spatial and temporal variations in pollutant removal and the interplay between different electrokinetic variables during EK remediation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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15. Oil resistivity of fluorine-free foams stabilized by silica nanoparticles and mixture of silicone and hydrocarbon surfactants.
- Author
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Sheng, Youjie, Hu, Die, Ma, Wenzhi, and Zhao, Qian
- Abstract
This study aims at exploring properties of fluorine-free foams co-stabilized by nanoparticles (NPs) and surfactant. The mixed dispersion liquids composed of silica NPs, nonionic hydrocarbon surfactant (APG-0810), and organosilicon surfactant (CoatOsil-77) was prepared. The NP-intensified foams under the action of n-heptane (flammable liquid) were focused by analyzing aggregation behavior of surfactants, initial foaming height, foams drainage and decay, and single vertical film stability of the mixed dispersion liquids. The findings show that the presence of surfactants improves surface activity of water obviously. After adding NPs, the interactions between surfactant molecules are destroyed but new aggregates formed. Foaming ability decreases but stability increases significantly with increasing NP concentration. After n-heptane is added, intensified interactions exist among surfactant molecules, NPs, and oil droplet, promoting formation of some larger aggregates and increasing the surface tension and viscosity but decreasing the conductivity and foaming ability. In addition, the presence of n-heptane accelerates foam drainage and volume decay and thinning process of the vertical liquid film. NPs with an appropriate concentration can improve foaming ability, foam stability, and the corresponding oil resistivity of foam. This study can provide theoretical guidance for the development of new fluorine-free foams used for liquid fuel fire. Highlights: Intense interactions exist among SiO
2 NPs, surfactant molecules, and oil droplets. Foaming ability is reduced by the presence of SiO2 NPs and oil droplets. SiO2 NPs with concentration above 1% can effectively improve foam oil resistivity. SiO2 NPs enhances foam oil resistivity be improving foam film stability under oil. [ABSTRACT FROM AUTHOR]- Published
- 2024
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16. Organobentonite fabrication assisted by surfactant octadecylamine intercalation under hydrothermal/solvothermal condition for effective direct yellow dye removal.
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Hakim, Yusuf Mathiinul, Mardiyanto, Royani, Idha, and Mohadi, Risfidian
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DIFFERENTIAL thermal analysis ,SCANNING electron microscopes ,LANGMUIR isotherms ,SCANNING electron microscopy ,STRUCTURAL stability - Abstract
This study utilizes a hydrothermal-solvothermal method to facilitate the fabrication of organobentonite (OB) by intercalating the surfactant octadecylamine (ODA) using several solvents (water (OB-Aq), ethanol (OB–Et), and mix 50% water/ethanol (OB-Aq/Et)). The physicochemical features of the materials were investigated using X-ray diffraction, Fourier transform infrared, scanning electron microscopy, Brunauer-Emmett-Teller surface analyzer, and thermogravimetry differential thermal analysis characterization. The study of structural properties found that surfactant intercalation transformed the basal spacing. This was shown by a lower x-ray diffraction value of 2θ at <6° and the presence of peeled-off layers in the scanning electron microscope image. The thermogravimetry analysis and regeneration adsorption evaluated the structural stability of OB, demonstrating its capacity to withstand temperatures up to 300 °C and undergo three cycles of adsorption. In addition, the adsorption processes on direct yellow are mainly characterized by the pseudo-first-order kinetic and Langmuir isotherm models. The interaction between alumina-silica bentonite and ODA chains in this investigation influenced the adsorption mechanism. The adsorption system is influenced by pH, temperature, and ion competition, which can induce the disintegration of the direct yellow structure from the surfaces of the adsorbent. The mesoporous structures obtained have the highest Langmuir chemisorption capacities for OB-Aq, OB-Et, and OB-Aq/Et, with values of 270.27 mg/g, 108.696 mg/g, and 2000 mg/g, respectively. This work suggests using an efficient method to fabricate OB for anionic dyes removal, specifically direct yellow. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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17. Characterization and treatment of industrial laundry wastewaters: a review.
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Crini, Grégorio, Lacalamita, Dario, Lichtfouse, Eric, Morin-Crini, Nadia, Liu, Chong, Wilson, Lee D., Picos-Corrales, Lorenzo A., Akhere, Mabel Amen, Sotiropoulou, Maria, Bradu, Corina, and Mongioví, Chiara
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INDUSTRIAL wastes ,WATER treatment plants ,SEWAGE disposal plants ,WATER purification ,WATER use - Abstract
The industrial laundry sector is a major user of water and chemicals such as surfactants, and one of the largest producers of wastewater. Although treated wastewaters comply with regulations, they still contain contaminants. Here we review laundry wastewater with focus on industrial laundry activities and their challenges, chemical composition of wastewater, and treatment techniques. We discuss advantages and drawbacks of treatment techniques that can be used as secondary treatment in already existing plants, or as tertiary treatment, i.e., complementary to an existing treatment. We observe that laundry is an expanding industrial sector with increasing water requirements, an abundant use of chemical substances, and increasingly stringent discharge regulations. There is a lack of chemical and biological knowledge on aqueous discharges. Moreover, the chemical composition, temporal variability, treatment information, and environmental and ecotoxicological data are poorly reported. The composition of wastewaters and additives, and their temporal variability are also poorly known. Similarly, detailed information on treatments is rare, and environmental and ecotoxicological data are poorly reported. Finding a tertiary water treatment process that is efficient, viable, and environmentally friendly is challenging since wastewater volumes are very high and contaminants are present at trace level in complex organo-mineral mixtures. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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18. Synthesis and application of cationic fluorocarbon surfactants.
- Author
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Zhang, Saipeng, Zhang, Mingxin, Liu, Xingjiang, and Wei, Liuhe
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CRITICAL micelle concentration ,CATIONIC surfactants ,SURFACE active agents ,FIREFIGHTING ,RAW materials ,FOAM ,ISOCYANATES - Abstract
In this paper, a series of cationic polyurethane fluorinated surfactants were synthesized using a series of isocyanates, and 1H, 1H, 2H,2H-tridecafluoro-1-octanol, 2-(dimethylamino)ethanol, and iodomethane as raw materials in a three-step sequential reaction. These fluorinated surfactants exhibited high surface activity and low critical micelle concentration. In addition, these fluorinated surfactants exhibited excellent wetting and emulsification properties at very low concentrations of 0.1 wt%. In addition the cationic polyurethane fluorinated surfactants are compounded into aqueous film-forming foam extinguishing agents, which exhibit excellent fire extinguishing properties. The desirable properties coupled with the simple and green preparation process make this strategy a new way to prepare sustainable alternatives to long fluoroalkyl chain surfactants. A new degradable cationic fluorocarbon surfactant prepared by coupling isocyanate and hydroxyl group was developed and applied to fire fighting. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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19. Cole–Hopf linearization of the thermocapillary Marangoni dynamics of a two-dimensional bubble with insoluble surfactant.
- Author
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Crowdy, Darren
- Abstract
The Marangoni stress-induced dynamics of a two-dimensional inviscid bubble loaded with insoluble surfactant moving in a linear temperature gradient is studied in the limit of small Reynolds, capillary and thermal Péclet numbers. The bubble moves due to the combined effects of thermocapillary Marangoni stresses and those induced by the advective-diffusive spreading of an initial concentration of surfactant on the bubble boundary. It is shown that this nonlinear multiphysics initial value problem is linearizable at any finite non-zero value of a surface Péclet number P e s governing the size of surface diffusion of the insoluble surfactant relative to its advective spreading. This is done by showing that the dynamics can be encoded in the evolution of a function, analytic and single-valued outside the bubble, that satisfies a complex partial differential equation of Burgers type. It is shown that this equation can be linearized by a complex generalization of the classical Cole–Hopf transformation. A numerical method is formulated to solve this linear partial differential equation and determine the Marangoni dynamics of a bubble with some initial surfactant concentration and illustrative calculations are carried out. Results are shown to be consistent with exact equilibrium solutions available from the formulation as P e s → 0 and P e s → ∞ and a perturbative formula for the bubble migration velocity at large but finite P e s . [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
- View/download PDF
20. 泡沫分馏技术的过程强化策略及其在食品 工业中的应用研究进展.
- Author
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程小东, 刘 伟, 杨春燕, 殷 昊, and 卢 珂
- Subjects
PROTEIN fractionation ,LITERATURE reviews ,DENATURATION of proteins ,FOAM ,MEDICAL drainage - Abstract
Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
21. Substantiating and Adopting Lung Ultrasound Scores to Predict Surfactant Need in Preterm Neonates with Respiratory Distress Syndrome within an Institution.
- Author
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Chan, Belinda, Torsitano, Christopher, Gordon, Sasha, Konana, Olive, and Singh, Yogen
- Subjects
STATISTICAL correlation ,PREDICTIVE tests ,PROFESSIONAL practice ,RECEIVER operating characteristic curves ,OXYGEN ,SMALL for gestational age ,RESEARCH funding ,NEONATAL intensive care units ,SCIENTIFIC observation ,ULTRASONIC imaging ,LUNGS ,NEONATAL intensive care ,TREATMENT effectiveness ,DESCRIPTIVE statistics ,DECISION making in clinical medicine ,CHILDREN'S hospitals ,TERTIARY care ,LONGITUDINAL method ,RESPIRATORY distress syndrome ,COMPARATIVE studies ,POINT-of-care testing ,PULMONARY surfactant ,SENSITIVITY & specificity (Statistics) - Abstract
Objective Administering surfactant timely and appropriately is important to minimize lung injury but remains challenging in preterm neonates with respiratory distress syndrome. The published literature supports that lung ultrasound (LUS) score can predict surfactant need. Neonatal LUS scanning specification and parameter setting guidelines have been recently published for standardization. However, variations in scanning protocols and machine settings hinder its clinical implementation widely. This observational study aims to internally validate the suggested LUS protocol in a neonatal intensive care unit to establish a correlation between LUS scores and surfactant need as the first step of integrating LUS in the clinical practice. Study Design LUS was performed on 40 eligible preterm neonates within 3 hours after birth or before surfactant administration between May 2020 and March 2021. The neonates were between 27 and 32 weeks' gestational age, and all had respiratory distress. Neonates with known congenital anomalies were excluded. A high-frequency linear probe was used to obtain LUS images from six lung zones which were scored using a 0 to 3 system, yielding a maximum of 18 points. Treating physicians were blinded to the LUS score. Receiver operating characteristic analysis determined the optimal LUS score cut-off for predicting surfactant need. Results Fifteen of the 40 neonates (38%) required higher oxygen fraction and received surfactant. In our cohort, an LUS score ≥10 was identified as the optimal cut-off for predicting surfactant need, with a sensitivity of 80% and specificity of 84%. The area under the curve was 0.8 (p = 0.0003). LUS predicted surfactant need at a median of 3.5 hours earlier than traditional clinical decision (p < 0.0037). Conclusion LUS is a helpful adjunct for predicting surfactant need in preterm neonates. This study describes an approach to implement the LUS protocol and score for clinical decision-making in the clinical practice. Key Points LUS is a helpful adjunct for predicting surfactant need in preterm neonates. Machine setting variation and probe selection may affect LUS image and score. LUS score should be validated at the local unit before clinical implementation. [ABSTRACT FROM AUTHOR]
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- 2024
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22. A nationwide survey on the management of neonatal respiratory distress syndrome: insights from the MUNICH survey in 394 Chinese hospitals.
- Author
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Chen, Long, Ji, Yong, Ju, Rong, Liu, Jiang-Qin, Liu, Ling, Shi, Jingyun, Wu, Hui, Wang, Lili, Xu, Falin, Yang, Chuanzhong, Zhang, Huayan, and Shi, Yuan
- Abstract
Background: At present, preterm infants with respiratory distress syndrome (RDS) in China present higher mortality and morbidity rates than those in high-income countries. The aim of this nationwide survey was to assess the clinical management of RDS in China. Methods: A nationwide cross-sectional survey to assess adherence to RDS management recommendations was performed. One neonatologist per hospital was randomly selected. The primary outcome was the key care of RDS management. Results: Among the 394 participating hospitals, 88·3% were birthing centres. The number of doctors and nurses per bed were 0·27 and 0·72, respectively. Antenatal corticosteroids (any dose) were administered to 90% of the women at risk of preterm birth at < 34 weeks of gestation (90·0% inborn vs. 50·0% outborn, p < 0·001). The median fraction of inspired oxygen (FiO
2 ) for initial resuscitation was 0·30 for babies born at ≤ 32 weeks of gestation and 0·25 for those born at > 32 weeks. T-piece resuscitators were available in 77·8% of delivery rooms (DRs) (tertiary hospitals: 82·5% vs. secondary hospitals: 63·0%, p < 0·001). Surfactant was used in 51·6% of the DRs. Less invasive surfactant administration (LISA) was used in 49·7% of the hospitals (tertiary hospitals: 55·3% vs. secondary hospitals: 31·5%, p < 0·001). Primary non-invasive ventilation was initiated in approximately 80·0% of the patients. High-frequency oscillation ventilation was primarily reserved for rescue after conventional mechanical ventilation (MV) failure. Caffeine was routinely used during MV in 59·1% of the hospitals. Bedside lung ultrasonography was performed in 54·3% of the health facilities (tertiary hospitals: 61·6% vs. secondary hospitals: 30·4%, p < 0·001). Qualified breast milk banks and Family Integrated Care (FICare) were present in 30·2% and 63·7% of the hospitals, respectively. Conclusions: Significant disparities in resource availability and guidelines adherence were evident across hospitals. Future strategies should address DR facilities and medication access, technical training, staff allocation, and ancillary facility development for a better management of RDS patients in China. [ABSTRACT FROM AUTHOR]- Published
- 2024
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- View/download PDF
23. Micelle Enabled Buchwald‐Hartwig Amination in Water with the Bening by Design Surfactant TPGS‐750‐M for the Synthesis of the JAK Inhibitor 4‐((2‐Chlorophenyl)amino)‐6‐((6‐methylpyridin‐2‐yl)amino)nicotinamide
- Author
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Jiang, Hao, Wu, Bin, Rufle, Dominik, Wang, Liping, Shi, Min, Parmentier, Michael, and Gallou, Fabrice
- Abstract
An efficient and scalable Buchwald‐Hartwig amination towards the synthesis of the API candidate 4‐((2‐Chlorophenyl)amino)‐6‐((6‐methylpyridin‐2‐yl)amino)nicotinamide as a JAK inhibitor was described. The process was developed using water and a water‐miscible co‐solvent. It was facilitated by the benign by design surfactant TPGS‐750‐M, that promoted the robust and reliable preparation of our target compound in high yields, with improved reaction profile and via an operationally simple protocol. [ABSTRACT FROM AUTHOR]
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- 2024
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24. Insight into the physical and chemical attributes of polypropylene microplastics.
- Author
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Jackariya, Nor Ku Nazatul Husna Mohd, Wahab, Nor Aimi Abdul, Isa, Norain, Othman, Norfaezatul Alysa, Zamri, Nor Ayuni, and Inderan, Vicinisvarri
- Subjects
SODIUM dodecyl sulfate ,FOURIER transform infrared spectroscopy ,POLLUTANTS ,MICROPLASTICS ,SCANNING electron microscopy - Abstract
Microplastics (MPs) are increasingly recognised for their significant impact on the environment and human health. Understanding MPs is crucial to grasp their widespread presence in various environmental areas. The unique properties of MPs, such as their small size, durability, and potential to adsorb and transport environmental pollutants, underscore the necessity of studying their characteristics. This study aims to investigate the physical and chemical characteristics of polypropylene microplastics (PPMPs) and address the dispersion stability issues associated with them. The PPMPs were characterised using scanning electron microscopy (SEM), revealing a surface structure marked by cracks, fractures, and a rough texture. The PPMPs were observed as irregularly shaped, white particles. Their size distribution spans from 14 to 96 µm, with a mean size of 50.00 µm. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the presence of polypropylene functional groups, specifically identifying characteristic peaks at 2952-2846 cm
-1 and 1456 -1376 cm-1 , indicating C-H stretching and bending vibrations, respectively, with additional peaks suggesting degradation. The effect of different concentrations of sodium lauryl sulfate (SLS) on PPMPs dispersion indicated that 5% SLS led to superior dispersion of PPMPs, thereby addressing the stability issue. These findings provide comprehensive insights into the physical and chemical attributes of PPMPs and their dispersion stability, offering a foundation for informed environmental assessments and the development of effective mitigation strategies. [ABSTRACT FROM AUTHOR]- Published
- 2024
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25. Influence of the Surface Tension of a Liquid on the Characteristics of the Cone of Its Spraying by an Ejection Atomizer.
- Author
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Arkhipov, V. A., Bondarchuk, I. S., Zolotoryov, N. N., and Perfil'eva, K. G.
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SMALL-angle scattering ,LIQUID surfaces ,DISTILLED water ,SURFACE active agents ,ATOMIZERS ,SURFACE tension - Abstract
Novel experimental data have been presented on the influence of the surface tension of a liquid on the dispersity of droplets in the spray cone of an ejection atomizer with forward and swirling gas feeds. The droplet-size distributions were measured with the optical method of small angles of the indicatrix of scattering. A decrease of nearly 10–17% in the median diameter of droplets of distilled water in the spray cone has been demonstrated with reduction in the coefficient of surface tension of water as a result of adding surfactants to it. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
26. Oil Displacement Mechanism of a Novel Surfactant.
- Author
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Rong, Guanghui, Liu, Yongtao, Xie, Weitao, and Chen, Xingshuo
- Subjects
CRITICAL micelle concentration ,ENHANCED oil recovery ,INTERFACIAL tension ,ROCK properties ,SURFACE active agents - Abstract
China's low-permeability reservoirs possess abundant resources characterized by poor rock properties, strong heterogeneity, and fine pore throats, leading to low displacement efficiency. This study expands the concentration window for achieving ultra-low interfacial tension (ULT) by adding co-surfactants to the primary surfactant. Research indicates that the critical micelle concentration (cmc) and corresponding interfacial tension (γcmc) of the compounded system are lower than those of individual components. When the molar ratio of M to Q is 1:1, the interaction parameter βm reaches its minimum value, indicating the strongest synergistic effect within the system. The compounded system achieves an oil-water interfacial tension as low as 0.0021 mN/m at 0.25% M + 0.025% Q, enhancing recovery efficiency by 0.88% compared to the single component M. Utilizing micro-etching microscopy and natural core physical model experiments, the compounded surfactant system's recovery efficiency increment reaches 19.7%, significantly surpassing water flooding effects. This provides robust support for the efficient development of the Jiyuan X reservoir. [ABSTRACT FROM AUTHOR]
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- 2024
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27. Evaluation of the Performance of New Surfactants and Study of Enhanced Recovery.
- Author
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Yang, Li, Yining, Zhao, Pei, He, Tao, Dong, Shaofei, Xue, Zixin, Li, and Weijin, He
- Subjects
INTERFACIAL tension ,MONOOLEIN ,SUCCINIC acid ,PETROLEUM ,RAW materials ,FOAM - Abstract
In order to improve the efficiency of crude oil recovery, reduce the adhesion and adsorption of crude oil in the formation, reduce the interfacial tension of oil and water to form a stable emulsion, the performance evaluation of new surfactants and methods for improving oil recovery are studied. The esterification reaction is used to synthesize the raw material of glyceryl monooleate succinic acid monoester, and the raw material is neutralized with an alkaline solution to prepare a new surfactant. Through experiments, the surfactant's interfacial tension, salt resistance, temperature resistance, emulsification, viscosity reduction and other properties were evaluated, and the effect of changing the oil recovery rate after using the surfactant was studied. Test results show that this new surfactant can significantly reduce the water-oil interfacial tension, and can still reduce the water-oil interfacial tension even in saline environments and high temperature environments. After the temperature reaches 50°C, the temperature resistance is basically stable; When the surfactant concentration of the water-oil ratio is lower than 7:3 and higher than 700mk/L, it can reduce the viscosity of the water-oil mixture; the surfactant has good foam performance and emulsification, and can effectively improve crude oil recovery. Use 0.25% mass fraction surfactant, can effectively improve oil recovery, but abnormal low-pressure environment will affect the recovery effect. [ABSTRACT FROM AUTHOR]
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- 2024
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28. Experimental Study of Gas Drive Chemical Analysis and Enhanced Recovery in Tight Oil Reservoirs.
- Author
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Li, Xianzheng, Pan, Chunfu, Chen, Hao, Zhang, Zheng, Wang, Shengzhou, and Ning, Kun
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ENHANCED oil recovery ,PETROLEUM reservoirs ,PETROLEUM ,GAS injection ,ANALYTICAL chemistry - Abstract
As an important unconventional oil and gas resource, tight oil reservoirs are difficult to achieve ideal recovery rates with conventional oil recovery methods. In this paper, the oil driving effect of different gases (CO
2 and N2 ) in tight reservoirs was investigated, and the auxiliary roles of chemicals such as surfactants and polymers in the gas driving process were also discussed. An autoclave was used for the different gas drive experiments, with a set pressure range of 10 MPa to 30 MPa, a constant temperature of 60°C, and the gas injection rate was adjusted to evaluate the drive effect. In addition, the effects of surfactants SDBS and C12-14 Pareth-7, as well as polymers PAM and HPAM at different concentrations on the gas drive effect were investigated. The results showed that the oil driving effect of CO2 was better than that of N2 , and the oil recovery of CO2 drive was increased by more than 20% at 30 MPa and 20 mL/min. With the addition of surfactant, SDBS increased the recovery by 15% at 0.3% concentration, while PAM increased the recovery by 10% at 0.4% concentration. This study demonstrated the superiority of CO2 gas drive in tight reservoirs and elucidated the enhancement effect of chemical adjuvants in the gas drive process by analyzing detailed experimental data. These findings provide an important theoretical basis and technical support for optimizing the gas-drive development scheme in tight reservoirs, which improves the crude oil recovery and has important practical application value. [ABSTRACT FROM AUTHOR]- Published
- 2024
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29. Physysichemical Properties of Quaternary Ammonium Salts Formed by Undecanoic and Tetradecanoic Acids with Trietanolamine.
- Author
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Shahverdiyeva, Asya
- Subjects
QUATERNARY ammonium salts ,CARBOXYLIC acids ,SURFACE tension ,SURFACE energy ,DISTILLATION - Abstract
The article presents the results of the study of the oil collecting and oil dispersing properties of the quaternary ammonium salts formed by undecanoic and tetradecanoic acids, which are monobasic carboxylic acids, with triethanolamine (TEA) in distilled, drinking, and sea waters contaminated with Balakhani Oil. The surface activity property of the products of different concentrations of these complexes was calculated using a tensiometer, and the elemental composition was calculated using the calculation method. A comparative study of the element composition of the salts of both acids formed with TEA shows that the mass fraction of carbon in the complex formed by tetradecanoic acid with TEA is higher than in the other complex. Comparison of the surface activity property of the complexes formed by undecane and tetradecanoic acid with TEA shows that the complex compound formed by tetradecanoic acid with TEA shows more surface activity property. Therefore, as the mass fraction of carbon element increases in the complexes formed by undecane and tetradecanoic acid with TEA, the complex compound shows more surface activity properties. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
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30. Interactive experimental study on microgroove structure and drag‐reducing additives in rotating disk apparatus.
- Author
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Chang, Ailian, Huang, Le, Huang, Benqing, and Vafai, Kambiz
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ROTATING disks ,REYNOLDS number ,SODIUM salicylate ,POLYETHYLENE oxide ,HYDRAULIC machinery - Abstract
A series of interactive experiments are conducted to analyze the drag reduction technology with a rotating disk apparatus that combines microgroove structure and drag‐reducing additives including polyethylene oxide (PEO), cetyltrimethyl ammonium chloride (CTAC), and sodium salicylate (NaSal). By varying the disk type, concentration of drag‐reducing additives, temperature, and Reynolds number (Re), the corresponding drag reduction rates are obtained effectively. The experimental results indicate that adding CTAC strengthens the heat degradation and shear resistance of PEO; while PEO can enhance the ability of CTAC to form micellar structures and balance energy distribution at low concentrations. Moreover, the synergistic effect of these two additives presents a better drag reduction performance with a maximum drag reduction rate of 24.1%; while the microgroove structure enhances the effect of active drag reduction. Therefore, the combination of active and passive drag reduction technology broadens the application of energy saving and consumption reduction in hydraulic rotating machinery. [ABSTRACT FROM AUTHOR]
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- 2024
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31. Less Invasive Surfactant Administration for Preterm Infants – State of the Art.
- Author
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Härtel, Christoph, Kribs, Angela, Göpel, Wolfgang, Dargaville, Peter, and Herting, Egbert
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CONTINUOUS positive airway pressure ,POSITIVE pressure ventilation ,PREMATURE infants ,RESPIRATORY distress syndrome ,SURFACE active agents - Abstract
Background: Less invasive surfactant administration (LISA) has become the preferred method of surfactant administration for spontaneously breathing babies on continuous positive airway pressure (CPAP). Summary: The development of LISA followed the need to combine CPAP and surfactant replacement as mainstay treatment options for respiratory distress syndrome, thereby avoided exposure to positive pressure ventilation. Key Messages: This review summarises the current knowns and unknowns of LISA including the physiological concept, its relevance for short-term and long-term outcomes and the challenges for practical implementation of LISA as part of a less invasive respiratory care bundle. Further, we provide an update of the evidence on alternatives to LISA, for example, nebulised surfactant administration, pharyngeal deposition of surfactant and delivery via supraglottic airway. [ABSTRACT FROM AUTHOR]
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- 2024
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32. 食品中自微乳体系的组成、制备及促进生物 活性物质生物利用的研究进展
- Author
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石长波, 徐 朔, 赵钜阳, 陈逸玉, 顾丽雅, and 李玉奇
- Subjects
SURFACE active agents ,BIOAVAILABILITY ,PETROLEUM ,DIET ,AWARENESS - Abstract
Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
33. Experimental investigation of surfactant adsorption during EOR and soil pollution control processes: Influence of surfactant concentration, water salinity, and clay type.
- Author
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Pishkoo, Arian, Sedaee, Behnam, and Bahramian, Alireza
- Subjects
SOIL pollution ,WATER salinization ,WATER pollution ,SURFACE active agents ,KAOLINITE - Abstract
Surfactant injection is a well-established method of chemical EOR processes. Surfactant adsorption into clay layers can prevent their proper performance and thus reduce the oil recovery factor. On the other hand, this adsorption property of clay materials can be used to prevent surface and underground water pollution and reduce soil pollution. In this experimental study, the effect of surfactant concentration, electrolyte type (NaCl and MgCl
2 ), and the solution salinity on fluid adsorption into the interlayer space of different clay types (bentonite and kaolinite) was investigated. XRF analysis was conducted on two relevant clay samples, and immersion and Washburn tests were performed on the desired samples with the Sigma 700 setup. Then, according to the clay type, the most optimal conditions were introduced for the surfactant solution used in the two areas of EOR and environmental processes related to reducing soil pollution. In the EOR processes, the optimal condition for the lowest adsorption amount is C (with 1 CMC concentration and salinity of 100,000 ppm for NaCl salt). This fluid works better in kaolinite formations. In the environmental field related to the reduction of soil pollution, if the pollutants we are looking for are R and S (with alkyl benzene sulfonic acid as the dominant agent), bentonite has a better performance than kaolinite in terms of adsorption and subsequently pollution control. If the polluting fluid contains MgCl2 ions in the exact salinity values, the adsorption amount and soil pollution control will be higher for both adsorbent clays than if our fluid has NaCl salinity. The study's findings have a wide range of applications in surfactant flooding designs, surfactant adsorption optimization, and can be generalized to other detergent types. [ABSTRACT FROM AUTHOR]- Published
- 2024
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34. Ethanol Production from Corncob Assisted by Polyethylene Glycol and Conversion of Lignin-Rich Residue into Lignosulfonate and Phenolic Acids.
- Author
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Maduzzi, Julieta, Thomas, Habila Yusuf, Fidelis, José Dário Silva, de Carvalho, José Valderisso Alfredo, Silva, Elano Costa, da Costa Filho, José Daladiê Barreto, Cavalcante, José Demétrio Nery, dos Santos, Everaldo Silvino, de Santana Souza, Domingos Fabiano, and de Araújo Padilha, Carlos Eduardo
- Subjects
ALKALINE hydrolysis ,POLYETHYLENE glycol ,FERULIC acid ,CORNCOBS ,PHENOLIC acids - Abstract
The economic competitiveness of 2G-bioethanol technology should improve through the improvement of the sugar release and the valorization of by-products, especially lignin. Thus, an integrated scheme with corncob was developed to produce ethanol using low dosages of cellulases and value-added products from the semi-simultaneous saccharification and fermentation (SSSF) residue. Enzymatic hydrolysis and SSSF of acid pretreated corncob (< 20 mesh and > 20 mesh) were carried out under cellulase dosages of 5, 10, and 15 FPU/g in the absence and presence of polyethylene glycol 1500 (PEG 1500). The SSSF residue was used to obtain lignosulfonate via sulfomethylation reaction and phenolic acids via alkaline hydrolysis using 4% (w/v) sodium hydroxide and 0–5% (v/v) hydrogen peroxide. Pretreated corncob < 20 mesh allowed the reduction of cellulase dosage to 5 FPU/g without compromising sugar release. The addition of PEG 1500 boosted sugar release, reaching 56.73 g/L glucose under 20% (w/v) solids. The maximum ethanol production of 31.64 g/L was obtained using 5 FPU/g cellulases, 2% (w/w) PEG 1500, and 20% (w/v) solids (gradual addition). FTIR confirmed the preparation of lignosulfonate from SSSF residue, and the surfactant showed good stabilization performance in oil/water systems (emulsification index≈30%). High yields of p-coumaric acid (8045.3 mg/100 g) and ferulic acid (1429.4 mg/100 g) were obtained in alkaline hydrolysis with 5% (v/v) hydrogen peroxide. Based on these findings, corncob is versatile and can create a biorefinery with high economic potential. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
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35. Experimental Study and Analysis of Chemical Modification of Coal Surfaces by Viscoelastic Surfactant Fracturing Fluids.
- Author
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Yang, Mengmeng, Gong, Shihui, and Cheng, Yugang
- Subjects
ANTHRACITE coal ,ANALYTICAL chemistry ,FRACTURING fluids ,FUNCTIONAL groups ,RAMAN spectroscopy ,ZETA potential - Abstract
The continuous deepening of coal-seam extraction has sharply increased both gas pressure and content. The use of viscoelastic surfactant fracturing fluids (VESFFs) has been demonstrated to effectively improve coal-seam permeability and mitigate the occurrence of gas disasters. After injection into coal, VESFFs interact with the coal and affect its surface characteristics. In this study, to characterize changes in zeta potential, oxygen-containing functional groups, and the microcrystalline structure of hard and soft coal surfaces under the influence of VESFFs with different formulations, zeta potential measurements and Fourier-transform infrared and Raman spectroscopies were performed. The VESFFs enhanced the electrostatic repulsion between the pore wall and coal particles, which is favorable for the removal of coal particles from hard and soft coal surfaces. The combination of cationic with zwitterionic viscoelastic surfactants (VESs) in the VESFFs exposed more hydrophilic functional groups on the surfaces of hard and soft coal, increasing wettability and affecting nanometer pores. A VESFF based on anionic and zwitterionic VESs as the primary agents could enhance the extension of the aromatic layer (L
a ) of the aromatic crystal nuclei and reduce the interlayer spacing (d002 ) of hard and soft coal, thereby increasing the volume of micropores. This research offers theoretical guidance for optimizing the primary components of VESFFs and elucidates the mechanism through which VESFFs act on nanopores in coal from a microscopic perspective. [ABSTRACT FROM AUTHOR]- Published
- 2024
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- View/download PDF
36. Do Different Amounts of Exogenous Surfactant Differently Influence Cerebrovascular Instability in a Consecutive Group of Preterm Babies? Preliminary Results from a Single-Center Experience.
- Author
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Calandrino, Andrea, Caruggi, Samuele, Vinci, Francesco, Battaglini, Marcella, Massirio, Paolo, Cipresso, Gaia, Andreato, Chiara, Brigati, Giorgia, Parodi, Alessandro, Polleri, Giulia, Minghetti, Diego, and Ramenghi, Luca Antonio
- Subjects
OXYGEN saturation ,PATIENT safety ,RESEARCH funding ,T-test (Statistics) ,STATISTICAL hypothesis testing ,SCIENTIFIC observation ,FISHER exact test ,BRAIN ,TREATMENT effectiveness ,DESCRIPTIVE statistics ,MANN Whitney U Test ,NEAR infrared spectroscopy ,HEAD ,MAGNETIC resonance imaging ,ONE-way analysis of variance ,RESPIRATORY distress syndrome ,CEREBRAL circulation ,COMPARATIVE studies ,DATA analysis software ,PATIENT monitoring ,CARBON dioxide ,PULMONARY surfactant ,EVALUATION - Abstract
Background: Thirty years ago, the first attempt by Saliba and colleagues was made to reduce the negative effects (hypercarbia) of exogenous surfactant (ES) by slowing its administration. Sixteen years later, we observed the first less invasive surfactant administration (LISA) attempt by Kribs and colleagues. Many studies, since that time, have tried to minimize the invasiveness of ES and subsequent cerebral blood flow perturbations through studies using near-infrared spectroscopy (NIRS). We sought to address this medical challenge by identifying a less problematic modality of ES administration by delivering multiple aliquots of ES instead of a single one, as typically performed. The aim of this study was to test the hypothesis that a different way of administering ES using more aliquots could be a safe alternative that should be assessed in further studies. Methods: Patients between 26 + 0 and 35 + 6 weeks of gestational age (GA) requiring ES administration were enrolled (April 2023–February 2024). Differently fractioned doses were delivered according to an arbitrary standard dosage (0.3 mL per aliquot in babies < 29 weeks; 0.6 mL in babies ≥ 29 weeks), while NIRS and transcutaneous CO
2 (tCO2 ) monitoring were always performed. ES's effectiveness was assessed based on the reduction in the Oxygen Saturation Index (OSI) after administration. Persistent desaturation, bradycardia, and airway obstruction were defined as adverse effects and used to evaluate safety during ES administration, as well as variability in NIRS-rSO2 values and tCO2 . Results: Twenty-four patients were enrolled with a median GA of 29 weeks (IQR 4.5) and BW of 1223 ± 560 g. In addition, 50% of the cohort received fewer than three aliquots, whereas the other 50% received more than three. Monitoring was started before the procedure and continued 30′ after the last ES aliquot administration. The variability in NIRS-SpO2 values was significantly higher in the group (p = 0.007) with a lower number of aliquots administered. Similarly, increased NIRS-rSO2 values (p = 0.003) and increased tCO2 levels (p = 0.005) were observed in infants who underwent an ES split after the administration of a low number of aliquots. Conclusions: Our data obtained from the group with > 3 fractionated doses of ES seem to justify the preparation of a more robust study, as the combination of reduced NIRS variability and reduced tCO2 maximum levels is consistent with more stable cerebral blood flow during the challenging time of ES administration. [ABSTRACT FROM AUTHOR]- Published
- 2024
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- View/download PDF
37. UTILIZATION OF SONIC BLOOM TECHNOLOGY COMBINATION OF COMPOST TEA AND SURFACTANTS TO INCREASE SOYBEAN PRODUCTIVITY (GLYCINE MAX (L.) MERRILL).
- Author
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Pujiwati, Istirochah
- Subjects
LIQUID fertilizers ,SURFACE active agents ,CROP yields ,SOYBEAN industry ,COMPOST tea ,FACTORIAL experiment designs ,FERTILIZERS ,LEAF area ,TECHNOLOGY - Abstract
Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
38. Effect of wettability on paper literature deacidification by ultrasonic atomization.
- Author
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Ma, Zhuoyao, Fan, Huiming, Liao, Yunfei, Yun, Baihe, Wang, Zehao, Wu, Ting, and Liu, Jianan
- Subjects
SURFACE tension ,WETTING ,ATOMIZATION ,LIQUID surfaces ,ULTRASONICS - Abstract
Acidification is an important factor in the aging of paper literature. Since most of the paper is sized and the surface tension of water is high, it is usually difficult for aqueous phase deacidification agent to penetrate the paper resulting in uneven deacidification. The addition of surfactant can effectively reduce the liquid surface tension and enhance the effect of deacidification with wetting properties improvement. In this paper, polysorbate-80 and polyether-modified trisiloxane surfactants were added to sodium propionate aqueous deacidification agent separately, researching the effect of wettability on the paper literature deacidification by ultrasonic atomization. The results show that SP-TRSE is effective, the maximum enhancement of deacidification agent absorption after adding wetting additives is 238.20 %, the minimum standard deviation of water content and alkali reserve after treatment is 3.87 and 0.005 respectively, the maximum increase in the internal mass fraction of sodium is 0.29 %. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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39. 基于 Ni 纳米颗粒的 SERS 基底制备及其性能.
- Author
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疏 港, 陈福彬, 张 烨, 苏艳梅, 张冶金, and 潘教青
- Abstract
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- 2024
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40. Synthesis and functionalization of carbon nanospheres from asphaltene fraction for crude oil upgrading and viscosity reduction.
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Hammadou née Mesdour, Souad, Boufades, Djamila, Dahou, Meriem, Moussiden, Anissa, Boussak, Hassina, Demim, Soraya, and Linda, Loucif Seiad
- Subjects
PETROLEUM ,VISCOSITY ,ASPHALTENE ,NANOFLUIDS ,CARBON - Abstract
Nanoparticles provide a promising, cost-effective eco-friendly solution to the challenges posed by heavy-oil reservoirs, significantly enhancing oil recovery rates by reducing viscosity without requiring extensive thermal inputs. In this study, carbon nanospheres (CNSs) and functionalized-CNSs nanofluids were prepared by incorporating surfactants (T80 or BMIMCl). These nanofluids were evaluated for their efficacy in upgrading crude oil, particularly focusing on viscosity-reduction. Rheological tests were conducted across varying shear rates (60–300 s
−1 ) and concentrations (0.02–3 wt.%) to comprehensively assess the impact of these additives on the crude oil's proprieties. The results showed a notable enhancement in crude oil viscosity reduction, with the following order observed: CNS-TiO2 < CNS-TiO2 /DMIMCl < CNS-TiO2 /T80, yielding reduction rates of 95%, 95.83%, and 97.08%, respectively, at an optimal dosage of 2.75 wt.% and a shear rate of 300 s−1 . The surface functionalization of CNS particles and their crystallinity are the main mechanisms driving the reduction in oil viscosity. Moreover, the properties of the crude oil were investigated upon the utilization of CNS-TiO2 /T80 nanofluid. It was found that this nanofluid led to a substantial reduction in sulfur content by 78.32% and a significant decrease in the percentage of heavier molecules, ranging from C12 to C35 and up to C36, with 47.76% and 97.98%, respectively. [ABSTRACT FROM AUTHOR]- Published
- 2024
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41. Applicability of cationic surfactants, anionic surfactants, and nonionic surfactants as foaming agents for foamed concrete: surface activity, foamability, and interaction with cement.
- Author
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Feng, Tugen, Yang, Hang, Zhang, Jian, and Zong, Chaoyang
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SURFACE tension measurement ,CATIONIC surfactants ,NONIONIC surfactants ,SURFACE tension ,ZETA potential ,FOAM ,SURFACE active agents ,ANIONIC surfactants - Abstract
Selecting the appropriate surfactant as a foaming agent is crucial in the production of foamed concrete. In this study, multiple technological approaches were employed for the investigation of the effect of three different types of surfactants as foaming agents; the approaches included surface tension measurement, zeta potential analysis, spectrophotometry, and nanoindentation. The results showed that the surface activity, solution viscosity, and environmental pH all influenced the generation and stability of foam in foaming agents. The adsorption process of surfactants onto cement particles was complex and could be effectively explained using the double-layer theory. The adsorption of anionic surfactant molecules on cement particles significantly altered the zeta potential, up to −17 mV, with an adsorption efficiency over 10 times greater than that of cationic surfactants and more than 5 times greater than that of nonionic surfactants. Furthermore, after cement hardening, the mechanical properties of the resulting pores were notably improved due to the presence of adsorbed anionic surfactants, and the maximum compressive strength could exceed 10 MPa. [ABSTRACT FROM AUTHOR]
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- 2024
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42. Enhanced photocatalytic performance of CuO nanoparticles synthesized via surfactant assisted hydrothermal method.
- Author
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Rajesh, S., Geetha, A., Guganathan, L., Suthakaran, S., Anbuvannan, M., Pragadeswaran, S., Santhamoorthy, Madhappan, Kim, S. C., Batoo, Khalid Mujasam, Ijaz, Muhammad Farzik, Mohammad, Mohammad. R., and Palaniappan, Sathish Kumar
- Subjects
GENTIAN violet ,HYDROTHERMAL synthesis ,PHOTOCATALYSTS ,X-ray diffraction ,COPPER oxide - Abstract
An effective approach to enhance the photocatalytic performance of CuO nanoparticles (NPs) is the use of hydrothermal synthesis. The CuO NPs were synthesized by hydrothermal technique in the presence of anionic surfactant. Structural, functional, morphological, chemical composition and optical properties of the synthesized NPs were characterized by using XRD, FTIR, SEM, UV-visible DRS and PL. The average crystallite size for pure, 0.05 M SHMP and 0.05 M SHMP assisted CuO samples are around 13 nm, 11 nm and 10 nm respectively. It was observed that the size of particle is affected by the nature of surfactant. Additionally, in all the samples, FTIR spectra show three identical Cu-O vibration modes that indicate the presence of crystalline CuO monoclinic structure. Thus, the spherical like CuO nanostructure can be used as an ideal material for photocatalytic performance. The synthesized NPs are then used to photo-catalytically degrade the methyl violet dye in aqueous media. Surfactant-assisted CuO NPs showed better photocatalytical activity than bare CuO NPs. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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43. Non‐invasive neurally adjusted ventilatory assist (NIV‐NAVA) reduces extubation failures in preterm neonates—A systematic review and meta‐analysis.
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Kuitunen, Ilari and Räsänen, Kati
- Subjects
CONTINUOUS positive airway pressure ,POSITIVE pressure ventilation ,TRACHEA intubation ,RANDOMIZED controlled trials ,NEWBORN infants - Abstract
Aim: To analyse the evidence of non‐invasive neurally adjusted ventilatory assist (NIV‐NAVA) in preterm neonates compared to nasal continuous positive airway pressure (nCPAP) or nasal intermittent positive pressure ventilation (NIPPV). Methods: We performed a systematic review and meta‐analysis of randomised controlled trials and included studies where NIV‐NAVA was analysed in preterm (<37 gestational weeks) born neonates. Our main outcomes were the need for endotracheal intubation, the need for surfactant therapy, and reintubation rates. Risk ratios (RRs) with 95% confidence intervals (CIs) were calculated. Results: A total of five studies were included. The endotracheal intubation rate was 25% in the NIV‐NAVA group and 26% in the nCPAP group (RR 0.91, CI: 0.56–1.48). The respective rates for surfactant therapy were 30% and 35% (RR 0.85, CI: 0.56–1.29). The reintubation rate in neonates previously invasively ventilated was 8% in the NIV‐NAVA group and 29% in the nCPAP/NIPPV group (RR 0.29, 95%CI: 0.10–0.81). Evidence certainty was rated as low for all outcomes. Conclusions: NIV‐NAVA as the primary respiratory support did not reduce the need for endotracheal intubation or surfactant therapy. NIV‐NAVA seemed to reduce the reintubation rate after extubation in pre‐term neonates. [ABSTRACT FROM AUTHOR]
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- 2024
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44. Surfactant-Based Chemical Washing to Remediate Oil-Contaminated Soil: The State of Knowledge.
- Author
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Zhao, Yanxin, Sun, Yuhuan, Sun, Haihan, Zuo, Fang, Kuang, Shaoping, Zhang, Shuwu, and Wang, Fayuan
- Subjects
SOIL remediation ,SOIL pollution ,POLLUTION remediation ,SOIL washing ,OIL spills - Abstract
As the energy demand increases, there is a significant expansion and utilization of oil resources, resulting in the inevitable occurrence of environmental pollution. Oil has been identified as a prevalent soil contaminant, posing substantial risks to the soil ecosystems. The remediation of soil contaminated with oil is a formidable undertaking. Increasing evidence shows that chemical washing, a remediation technique employing chemical reagents like surfactants to augment the solubilization, desorption, and separation of petroleum hydrocarbons in soil, proves to be an efficacious approach, but the latest advances on this topic have not been systematically reviewed. Here, we present the state of knowledge about the surfactant-based chemical washing to remediate oil-contaminated soil. Using the latest data, the present article systematically summarizes the advancements on ex situ chemical washing of oil pollution and provides a concise summary of the underlying principles. The use of various surfactants in chemical washing and the factors influencing remediation efficiency are highlighted. Based on the current research status and knowledge gaps, future perspectives are proposed to facilitate chemical washing of oil-polluted soil. This review can help recognize the application of chemical washing in the remediation of oil-polluted soil. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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45. Experimental investigation on the stability of foam using combination of anionic and zwitterionic surfactants: A screening scenario to obtain optimum compound.
- Author
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Shahmarvand, Samiye, Ameli, Forough, Mohammadi, Saber, and Hossein Abad Fouladi, Kazem
- Subjects
SODIUM dodecyl sulfate ,ANIONIC surfactants ,ENHANCED oil recovery ,INTERFACIAL tension ,GAS injection ,FOAM - Abstract
The use of foam injection as an enhanced oil recovery (EOR) technique has been suggested since the 1960s to address issues with gas injection. Foam is composed of gas, water, and surfactant, which is utilized to stabilize the foam. This study investigates the synergy effect of anionic surfactant and two zwitterionic surfactants on enhancing solution stability. The anionic surfactant used is sodium dodecyl sulfate, while the chosen zwitterionic surfactants are cocamidopropy hydroxy sultine and Cocamido Propyl Betaine. Analyzing the images of the generated foam showed that initially, the small and uniform bubbles are formed in all concentrations. The foam size is then increased and in concentrations higher than a critical value, the bubbles grow faster which is likely due to the formation of micelles and deposition of surfactants. This leads to early collapse of the foam structure. The quantitative half-life results approved that the most optimal compound was obtained with equal proportions of sodium dodecyl sulfate and Cocamido Propyl Betaine with concentration of 3 wt% (1:1 ratio, 0.15 wt%-0.15 wt%). To quantitatively study on foam characteristics, conductivity and interfacial tension tests were performed. The results of the conductivity tests showed that micelles were formed in concentrations of more than 0.3 wt%. Interfacial tension measurements revealed that addition of a small amount of surfactants to the base solution, led to reduction of the interfacial tension value from 29.2 (mN/m) in base solution to less than 1 mN/m for solutions treated with surfactant. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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46. Synthesis of copolymer of aniline-o-phenylenediamine using nonionic surfactant Triton X-100: analysis of electrical conductivities and supercapacitor properties.
- Author
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Chandrasekaran, N., Madheswari, D., and Sudarsan, S.
- Abstract
A porous structure of copolymer poly (aniline-co–o-phenylenediamine) has been fabricated by chemical oxidation process with nonionic surfactant Triton X-100. Different ratios of monomers (1:9, 5:5 and 9:1) have been utilized; structure and surface morphology has been analyzed by FTIR and SEM–EDX techniques. The UV, XRD and BET surface area measurement were also done. The electrochemical techniques such as cyclic voltammetry and electrochemical impedance were used to evaluate electrochemical capacitance performances. The copolymer comprising equimolar mixture of monomers displayed high surface area that helps to amplify the diffusion of electrolyte ions. Hence, the specific capacitance of developed copolymer has been determined as 989 F g
−1 at 5 mA cm−2 current density from galvanostatic charge–discharge studies with retainability of 84.94% capacitance after 100 cycles. [ABSTRACT FROM AUTHOR]- Published
- 2024
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- View/download PDF
47. COMPARATIVE CHARACTERISTICS OF THE CONDITION OF TISSUE UPPER RESPIRATORY TRACT IN CHILDREN WITH RESPIRATORY DISEASES LIVING IN KYRGYZSTAN, LOCATED AT DIFFERENT ALTITUDES ABOVE SEA LEVEL.
- Author
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I. D., ISMAILOV, R. K., KALMATOV, F., RAHIM, A. A., MOMUNOVA, and N., KILINÇ
- Subjects
RESPIRATORY diseases ,PEDIATRIC respiratory diseases ,SEA level ,BRONCHIAL diseases ,ALTITUDES ,MOUNTAIN sickness ,COUGH - Abstract
The respiratory tract acts as a crucial barrier influenced by environmental factors, particularly affecting the homeostasis of its mucous membranes. Environmental conditions, including climate and atmospheric composition, play a significant role in the development and progression of respiratory diseases such as bronchial asthma and allergic rhinitis. Various risk factors, including genetic predisposition, viral infections, allergen exposure, and pollutants, along with changes in the microbiome, are key determinants in the manifestation and progression of these diseases. Certain pollutants like ozone (O3), nitrogen dioxide (NO2), and particulate matter (PM2.5) contribute to airway inflammation and hyperresponsiveness, potentially leading to increased oxidative stress and respiratory distress. This study aims to comparatively analyze the clinical characteristics and processes of free radical oxidation in the tissues of the respiratory tract of children with respiratory diseases living at different altitudes in Kyrgyzstan. A total of 209 children, including 104 with chronic respiratory diseases and 105 healthy controls, were examined. The study included clinical examinations, endoscopic evaluations, and biopsies when necessary. Biological samples such as exhaled air condensate and nasal lavages were collected to measure various biochemical indicators including total lipids, hydroperoxides, diene conjugates, and oxidative index. Preliminary results indicate that children residing at higher altitudes exhibit more pronounced changes in respiratory tissues, likely due to climatic and environmental factors specific to high-altitude regions. These children showed significantly higher levels of free radical oxidation products and altered surface tension in biological samples compared to those living at lower altitudes. Complaints such as shortness of breath, difficulty breathing, cough, and nasal congestion were also more frequent among children at higher altitudes. The study highlights the need for further research to better understand the impact of altitude on respiratory health and to develop effective strategies for the treatment and prevention of respiratory diseases in children. Future research should focus on the longitudinal tracking of respiratory health, detailed environmental assessments, and the development of targeted public health strategies to address the unique challenges faced by high-altitude populations. Ultimately, this research aims to improve respiratory health outcomes for children living in diverse geographic settings. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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48. Offsetting Dense Particle Sedimentation in Microfluidic Systems.
- Author
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Anyaduba, Tochukwu Dubem and Rodriguez-Manzano, Jesus
- Subjects
MICROGELS ,FLUID dynamics ,FLOW meters ,IMAGE analysis ,PARTICLE tracks (Nuclear physics) - Abstract
Sedimentation is an undesirable phenomenon that complicates the design of microsystems that exploit dense microparticles as delivery tools, especially in biotechnological applications. It often informs the integration of continuous mixing modules, consequently impacting the system footprint, cost, and complexity. The impact of sedimentation is significantly worse in systems designed with the intent of particle metering or binary encapsulation in droplets. Circumventing this problem involves the unsatisfactory adoption of gel microparticles as an alternative. This paper presents two solutions—a hydrodynamic solution that changes the particle sedimentation trajectory relative to a flow-rate dependent resultant force, and induced hindered settling (i-HS), which exploits Richardson–Zaki (RZ) corrections of Stokes' law. The hydrodynamic solution was validated using a multi-well fluidic multiplexing and particle metering manifold. Computational image analysis of multiplex metering efficiency using this method showed an average reduction in well-to-well variation in particle concentration from 45% (Q = 1 mL/min, n = 32 total wells) to 17% (Q = 10 mL/min, n = 48 total wells). By exploiting a physical property (cloud point) of surfactants in the bead suspension in vials, the i-HS achieved a 58% reduction in the sedimentation rate. This effect results from the surfactant phase change, which increases the turbidity (transient increase in particle concentration), thereby exploiting the RZ theories. Both methods can be used independently or synergistically to eliminate bead settling in microsystems or to minimize particle sedimentation [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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49. Crystal Facet Control of Nickel–Cobalt Sulfide Nanostructure and Study of Supercapacitor Performance.
- Author
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Yin, Huiqun, Yang, Rui, Huang, Xian, Shi, Xiuyan, Li, Wangsheng, Mo, Yiyan, Zhang, Kaiyou, Qin, Aimiao, and Dai, Shuge
- Subjects
SUPERCAPACITOR performance ,ENERGY density ,CARBON electrodes ,NEGATIVE electrode ,CRYSTAL morphology ,SUPERCAPACITOR electrodes - Abstract
Supercapacitors require excellent cycling stability and rate capability for electrodes. The NiCo
2 S4 spinel structure has caught much attention for its high conductivity and high theoretical specific capacity. However, due to the lack of active sites, it has been restricted in supercapacitors. In this research, the NiCo2 S4 nano-material with needle, sheet and porous network morphologies were prepared by the addition of different kinds of surfactants via a simple hydrothermal method. At 1 mA/cm2 , capacitance of these NiCo2 S4 nanomaterials is measured as 2.09 F/cm2 , 3.22 F/cm2 , and 4.42 F/cm2 , respectively. It was found that the exposure ratio of (111) and (220) crystal facets also has an effect on electrochemical performance, and NiCo2 S4 with I (1 1 1) /I (2 2 0) of 3:1 showed better performance. Furthermore, NiCo2 S4 -PN//AC asymmetrical supercapacitor was assembled with NiCo2 S4 -PN serving as positive electrode and activated carbon (AC) as negative electrode. At a power density of 7.284 mW/cm2 , energy density achieved was 0.625 mWh/cm2 . Additionally, capacitance retention rate remained at 79.6% of initial capacitance after 1500 cycles. These outcomes are of great significance for developing more efficient, stable and reliable transition metal sulfide-based supercapacitors. NiCo2 S4 nanomaterials with needle, sheet, and porous network morphologies with different exposure ratios of (111)/(220) crystal facets were obtained using a simple two-step hydrothermal method. The type of surfactant plays a key role in the preparation of NiCo2 S4 nanomaterials. The cyclic stability and rate capability of NiCo2 S4 nanomaterials were improved by increasing the ratio of exposed (111)/(220) crystal facets. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
50. Surfactant combined with PASP enhance electrokinetic remediation removal heavy metal and hydrocarbon from contaminated soil.
- Author
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Tang, Jian, Tang, Hengjun, Liu, Guo, Zhang, Suyi, Ao, Zonghua, Sima, Weiping, Wang, Haiyue, Zhang, Haoran, Liang, Rui, and Liang, Chao
- Abstract
In this work, a new electrokinetic remediation technology was used to remove heavy metal and hydrocarbon from contaminated soil. The surfactant combined with PASP (Polyaspartic acid) was used to enhance heavy metal and hydrocarbon removing from contaminated soil. Electric current, soil pH, electroosmotic flow, water content variation, heavy metal removal efficiency and residual content distribution, heavy metal speciation, removal of TPH (total petroleum hydrocarbons), group composition of oil, mechanism of enhance electrokinetic remediation were investigated during the electrokinetic remediation process. Results indicated that Rhamnolipid, PASP, Tween 80 and SDS (sodium dodecyl sulphate) can reduce the heavy metal precipitation during the electrokinetic remediation process. Also, it can promote EOF (electroosmotic flow) and electrolyte evaporation during the EK remediation. The rhamnolipid (3.0 g.L
−1 ) combined with PASP (3.0 g.L−1 ) can significantly improve Cu, Cr, Ni, Pb and hydrocarbon mobility and solubility during the EK remediations. Cu, Cr, Ni and Pb obtained the dominant removal efficiencies, which were 66.0 ± 3.45%, 61.2 ± 4.35%, 67.1 ± 3.21%, 61.8 ± 4.22%, respectively. Also, the TPH has attained a dominant removal efficiency of 80.2 ± 4.36% after the enhanced electrokinetic remediation. This research provides a novel in-situ remediation approach for reducing heavy metals and hydrocarbon from contaminated soil in an environmentally friendly way. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
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