Preparation and Performance Evaluation of Gemini Sulphobetaine Surfactant Bis{[(N-methyl-N-(3-alkoxy-2-hydroxy) propyl-N-(3-sulfonic) propyl] methylene}

2021 ◽  
Vol 58 (6) ◽  
pp. 468-474
Author(s):  
Zhonghua Zuo ◽  
Ming Zhou ◽  
Mao Liao ◽  
Pengao Peng ◽  
Jingfeng Zhang

Abstract Surfactants are very often used in tertiary oil production. However, the conventional surfactants cannot be used in high salinity reservoirs of tertiary oil production because the high salinity leads to the deactivation of the surfactants. Gemini sulpho-betaine surfactants have been developed to meet the requirements of tertiary oil production in such reservoirs. In this study, the Gemini sulphobetaine surfactant (bis{[(N-methyl-N-(3-alkoxy-2-hydroxy)propyl-N-(3-sulfonate)propyl]methylene}) was prepared by etherification, ring opening reaction and sulfonation reaction with decyl alcohol, epichlorohydrin, N,N’-dimethyl ethylene diamine and 1,3-propanesultone. The experimental conditions obtained are: the ratio of 1,3-propanesulfonic acid lactone to tertiary amine intermediate = 2.3 : 1, reaction temperature = 70°C and reaction time = 11 h. The analysis of the infrared spectrum showed that the structure of the synthesised substance corresponds to that of a Gemini sulphobetaine surfactant. The chemical shifts of the groups were determined by 1HNMR structural characterisation of the products. The surface tension, emulsifying properties, foaming properties and wetting properties were investigated. The results showed that the surfactant has good foaming properties and good compatibility in a high salt environment.

2016 ◽  
Vol 12 (4) ◽  
pp. 21-32
Author(s):  
Anna Kwiatkowska ◽  
Małgorzata Mróz

The aim of this study was to examine the effects of stereotypical and counter-stereotypicalinformation on the self-esteem and cognitive performance of 10-year-old children. Our sampleconsisted of 37 girls and 37 boys. Children were presented with 10 “mathematical” puzzles in threeexperimental conditions: stereotypical (boys are better), counter-stereotypical (girls are better), andthe control condition (no particular information). Self-esteem was measured using a non-verbaltask. The results showed a significant interaction effect of “condition x sex” on self-esteem andperformance. Girls revealed no significant differences between control and experimental conditions,while boys showed a significant drop in self-esteem and performance in the counter-stereotypicalcondition as compared to the control condition and a significant lift in self-esteem and performancein the stereotypical condition as compared to the control condition.


2021 ◽  
Vol 22 (12) ◽  
pp. 6592
Author(s):  
Artur Seweryn ◽  
Tomasz Wasilewski ◽  
Anita Bocho-Janiszewska

The article shows that the type and concentration of inorganic salt can be translated into the structure of the bulk phase and the performance properties of ecological all-purpose cleaners (APC). A base APC formulation was developed. Thereafter, two types of salt (sodium chloride and magnesium chloride) were added at various concentrations to obtain different structures in the bulk phase. The salt addition resulted in the formation of spherical micelles and—upon addition of more electrolyte—of aggregates having a lamellar structure. The formulations had constant viscosities (ab. 500 mPa·s), comparable to those of commercial products. Essential physical-chemical and performance properties of the four formulations varying in salt types and concentrations were evaluated. It was found that the addition of magnesium salt resulted in more favorable characteristics due to the surface activity of the formulations, which translated into adequately high wettability of the investigated hydrophobic surfaces, and their ability to emulsify fat. A decreasing relationship was observed in foaming properties: higher salt concentrations lead to worse foaming properties and foam stability of the solutions. For the magnesium chloride composition, the effect was significantly more pronounced, as compared to the sodium chloride-based formulations. As far as safety of use is concerned, the formulations in which magnesium salt was used caused a much lesser irritation compared with the other investigated formulations. The zein value was observed to decrease with increasing concentrations of the given type of salt in the composition.


2021 ◽  
Author(s):  
Xia Yin ◽  
Tianyi Zhao ◽  
Jie Yi

Abstract The water channeling and excess water production led to the decreasing formation energy in the oilfield. Therefore, the combined flooding with dispersed particle gel (DPG) and surfactant was conducted for conformance control and enhanced oil recovery in a high temperature (100-110°C) high salinity (>2.1×105mg/L) channel reservoir of block X in Tahe oilfield. This paper reports the experimental results and pilot test for the combined flooding in a well group of Block X. In the experiment part, the interfacial tension, emulsifying capacity of the surfactant and the particle size during aging of DPG were measured, then, the conformance control and enhanced oil recovery performance of the combined flooding was evaluated by core flooding experiment. In the pilot test, the geological backgrounds and developing history of the block was introduced. Then, an integrated study of EOR and conformance control performance in the block X are analyzed by real-time monitoring and performance after treatment. In addition, the well selection criteria and flooding optimization were clarified. In this combined flooding, DPG is applied as in-depth conformance control agent to increase the sweep efficiency, and surfactant solution slug following is used for improve the displacement efficiency. The long term stability of DPG for 15 days ensures the efficiency of in-depth conformance control and its size can increase from its original 0.543μm to 35.5μm after aging for 7 days in the 2.17×105mg/L reservoir water and at 110°C. In the optimization, it is found that 0.35% NAC-1+ 0.25% NAC-2 surfactant solution with interfacial tension 3.2×10-2mN/m can form a relatively stable emulsion easily with the dehydrated crude oil. In the double core flooding, the conformance control performance is confirmed by the diversion of fluid after combined flooding and EOR increases by 21.3%. After exploitation of Block X for 14 years, the fast decreasing formation energy due to lack of large bottom water and water fingering resulted in a decreasing production rate and increasing watercut. After combined flooding in Y well group with 1 injector and 3 producers, the average dynamic liquid level, daily production, and tracing agent breakthrough time increased, while the watercut and infectivity index decreased. The distribution rate of injected fluid and real-time monitoring also assured the conformance control performance. The oil production of this well group was increased by over 3000 tons. Upon this throughout study of combined flooding from experiment to case study, adjusting the heterogeneity by DPG combined with increasing displacement efficiency of surfactant enhanced the oil recovery synergistically in this high salinity high temperature reservoir. The criteria for the selection and performance of combined flooding also provides practical experiences and principles for combined flooding.


1996 ◽  
Vol 80 (2) ◽  
pp. 452-457 ◽  
Author(s):  
K. Vandenberghe ◽  
N. Gillis ◽  
M. Van Leemputte ◽  
P. Van Hecke ◽  
F. Vanstapel ◽  
...  

This study aimed to compare the effects of oral creatine (Cr) supplementation with creatine supplementation in combination with caffeine (Cr+C) on muscle phosphocreatine (PCr) level and performance in healthy male volunteers (n = 9). Before and after 6 days of placebo, Cr (0.5 g x kg-1 x day-1), or Cr (0.5 g x kg-1 x day-1) + C (5 mg x kg-1 x day-1) supplementation, 31P-nuclear magnetic resonance spectroscopy of the gastrocnemius muscle and a maximal intermittent exercise fatigue test of the knee extensors on an isokinetic dynamometer were performed. The exercise consisted of three consecutive maximal isometric contractions and three interval series of 90, 80, and 50 maximal voluntary contractions performed with a rest interval of 2 min between the series. Muscle ATP concentration remained constant over the three experimental conditions. Cr and Cr+C increased (P < 0.05) muscle PCr concentration by 4-6%. Dynamic torque production, however, was increased by 10-23% (P < 0.05) by Cr but was not changed by Cr+C. Torque improvement during Cr was most prominent immediately after the 2-min rest between the exercise bouts. The data show that Cr supplementation elevates muscle PCr concentration and markedly improves performance during intense intermittent exercise. This ergogenic effect, however, is completely eliminated by caffeine intake.


eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Simon Erlendsson ◽  
Kamil Gotfryd ◽  
Flemming Hofmann Larsen ◽  
Jonas Sigurd Mortensen ◽  
Michel-Andreas Geiger ◽  
...  

The Neurotransmitter:Sodium Symporters (NSSs) represent an important class of proteins mediating sodium-dependent uptake of neurotransmitters from the extracellular space. The substrate binding stoichiometry of the bacterial NSS protein, LeuT, and thus the principal transport mechanism, has been heavily debated. Here we used solid state NMR to specifically characterize the bound leucine ligand and probe the number of binding sites in LeuT. We were able to produce high-quality NMR spectra of substrate bound to microcrystalline LeuT samples and identify one set of sodium-dependent substrate-specific chemical shifts. Furthermore, our data show that the binding site mutants F253A and L400S, which probe the major S1 binding site and the proposed S2 binding site, respectively, retain sodium-dependent substrate binding in the S1 site similar to the wild-type protein. We conclude that under our experimental conditions there is only one detectable leucine molecule bound to LeuT.


2021 ◽  
pp. 019262332110679
Author(s):  
Yuval Ramot ◽  
Serge Rousselle ◽  
Michal Steiner ◽  
Yossi Lavie ◽  
Nati Ezov ◽  
...  

One of the challenging aspects of minimal invasive surgery (MIS) is intracorporal suturing, which can be significantly time-consuming. Therefore, there is a rising need for devices that can facilitate the suturing procedure in MIS. Su2ura Approximation Device (Su2ura Approximation) is a novel device developed to utilize the insertion of anchors threaded with stitches to allow a single action placement of a suture. The objective of this study was to evaluate the long-term safety and tissue approximation of Su2ura Approximation in comparison to Endo Stitch + Surgidac sutures in female domestic pigs. All incision sites were successfully closed by both methods. Firm consolidation within and around the incision site was noted in several animals in both treatment groups, which corresponded histopathologically to islands of ectopic cartilage or bone spicules within the fibrotic scar. These changes reflect heterotopic ossification that is commonly seen in the healing of abdominal operation sites in pigs. No other abnormal findings were observed throughout the study period. In conclusion, the use of Su2ura Approximation under the present experimental conditions revealed no safety concerns.


Author(s):  
Diego Soto ◽  
Juan Antonio García-Herrero ◽  
Rodrigo J. Carcedo

This research aims at studying the effect of feedback on well-being (vitality, and positive and negative affect), competence valuation, perceived competence, motivation, and performance (throwing speed and accuracy) in a throwing task. Thirty nine expert women handball players, with experience in international handball competitions, participated in this study. They were indiscriminately ascribed to one of three different experimental conditions measuring feedback: (positive, negative, and none). Significant differences in well-being (positive affect) and throwing speed were found among the three feedback groups. More concretely, higher levels of positive affect and throwing speed were found in the negative feedback group in comparison with the other two groups (positive and no-feedback). These results have important implications for athletes’ well-being and performance, and for coaches’ training programs.


1991 ◽  
Vol 17 (1) ◽  
pp. 47-55 ◽  
Author(s):  
James E. Gilliam

Little systematic attention has been given to examining the effects of the color Baker-Miller pink on emotionally disturbed students, and research has yielded conflicting results. In this study two groups of students (14 emotionally disturbed students and 16 regular education students) were exposed to two experimental conditions with different visual stimuli — white and Baker-Miller pink. Group One was exposed to the white condition followed by the pink condition. Group Two was exposed initially to the pink condition followed by the white condition. Blood pressure, pulse rate, grip strength, and performance on the Digit-Symbol subtest of the WAIS-R were monitored under both experimental conditions. Multivariate analysis of variance revealed significant differences on systolic and diastolic blood pressure results but not on pulse, grip strength, nor the Digit-Symbol test. Caution is advised to persons considering using Baker-Miller pink for treatment of aggression, anxiety, and concentration.


2016 ◽  
Vol 9 ◽  
pp. S1053-S1058 ◽  
Author(s):  
Jumat Salimon ◽  
Bashar Mudhaffar Abdullah ◽  
Nadia Salih

2010 ◽  
Vol 33 ◽  
pp. 251-253
Author(s):  
Peng Zhang ◽  
Gang Chen ◽  
Bin Guo ◽  
Shu Kang Cheng

Porous membrane materials have the universal use, so it is widely considered as one of the most promising high-tech. Different membranes have different preparation methods. In this paper, the sol-gel method was applied to prepare silica particles using ammonia as catalyst of TEOS hydrolysis, then silica particles were mixed with polyethylene, and finally silica particles were dissolved with hydrofluoric acid, leaving holes, the porous materials were obtained. The results show that: (1) In this experimental conditions, the size of silica particles are closely related to the water content of the system. (2) The size of silica particles affects the agglomeration of particles. The size of silica particles are smaller, the agglomeration is more obvious. (3) As the content of PE increases, the porosity of the samples decreases continuously; in theory, when the content of silica is low, the hole will be greater.


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