Fluorescence Recognition of Anions Using a Heteroditopic Receptor: Homogenous and Two-Phase Sensing

In contrast to monotopic receptor 3, the anthracene functionalized squaramide dual-host receptor 1 is capable of selectively extracting sulfate salts, as was evidenced unambiguously by DOSY, mass spectrometry, fluorescent and ion chromatography measurements. The receptors were investigated in terms of anion and ion pair binding using the UV–vis and 1H NMR titrations method in acetonitrile. The reference anion receptor 3, lacking a crown ether unit, was found to lose the enhancement in anion binding induced by the presence of cations. Besides the ability to bind anions in an enhanced manner exhibited by ion pair receptors 2 and 4, changing the 1-aminoanthracene substituent resulted in their exhibiting a lower anion affinity than receptor 1. By using receptor 1 and adjusting the water content in organic phase it was possible to selectively detect sulfates both by “turn-off” and “turn-on” fluorescence, and to do so homogenously and under interfacial conditions. Such properties of receptor 1 have allowed the development of a new type of sensor capable of recognizing and extracting potassium sulfate from the aqueous medium across a phase boundary, resulting in an appropriate fluorescent response in the organic solution.

Download Full-text

Potentiometric Surfactant Sensor Based on 1,3-Dihexadecyl-1H-benzo[d]imidazol-3-ium for Anionic Surfactants in Detergents and Household Care Products

Molecules ◽

10.3390/molecules26123627 ◽

2021 ◽

Vol 26 (12) ◽

pp. 3627

Author(s):

Nikola Sakač ◽

Dubravka Madunić-Čačić ◽

Dean Marković ◽

Lucija Hok ◽

Robert Vianello ◽

...

Keyword(s):

Anionic Surfactants ◽

Negative Impact ◽

Ion Pair ◽

Two Phase ◽

Potentiometric Response ◽

Titration Curves ◽

Signal Change ◽

Nernstian Slope ◽

Good Agreement

A 1,3-dihexadecyl-1H-benzo[d]imidazol-3-ium-tetraphenylborate (DHBI-TPB) ion-pair implemented in DHBI-TPB surfactant sensor was used for the potentiometric quantification of anionic surfactants in detergents and commercial household care products. The DHBI-TPB ion-pair was characterized by FTIR spectroscopy and computational analysis which revealed a crucial contribution of the C–H∙∙∙π contacts for the optimal complex formation. The DHBI-TPB sensor potentiometric response showed excellent analytical properties and Nernstian slope for SDS (60.1 mV/decade) with LOD 3.2 × 10−7 M; and DBS (58.4 mV/decade) with LOD 6.1 × 10−7 M was obtained. The sensor possesses exceptional resistance to different organic and inorganic interferences in broad pH (2–10) range. DMIC used as a titrant demonstrated superior analytical performances for potentiometric titrations of SDS, compared to other tested cationic surfactants (DMIC > CTAB > CPC > Hyamine 1622). The combination of DHBI-TPB sensor and DMIC was successfully employed to perform titrations of the highly soluble alkane sulfonate homologues. Nonionic surfactants (increased concentration and number of EO groups) had a negative impact on anionic surfactant titration curves and a signal change. The DHBI-TPB sensor was effectively employed for the determination of technical grade anionic surfactants presenting the recoveries from 99.5 to 101.3%. The sensor was applied on twelve powered samples as well as liquid-gel and handwashing home care detergents containing anionic surfactants. The obtained results showed good agreement compared to the outcomes measured by ISE surfactant sensor and a two-phase titration method. The developed DHBI-TPB surfactant sensor could be used for quality control in industry and has great potential in environmental monitoring.

Download Full-text

ByShard

Proceedings of the VLDB Endowment ◽

10.14778/3476249.3476275 ◽

2021 ◽

Vol 14 (11) ◽

pp. 2230-2243

Author(s):

Jelle Hellings ◽

Mohammad Sadoghi

Keyword(s):

Data Management ◽

Phase Locking ◽

Large Data ◽

General Purpose ◽

Management Systems ◽

Two Phase ◽

Data Management Systems ◽

Malicious Behavior ◽

Byzantine Failures ◽

Do So

The emergence of blockchains has fueled the development of resilient systems that can deal with Byzantine failures due to crashes, bugs, or even malicious behavior. Recently, we have also seen the exploration of sharding in these resilient systems, this to provide the scalability required by very large data-based applications. Unfortunately, current sharded resilient systems all use system-specific specialized approaches toward sharding that do not provide the flexibility of traditional sharded data management systems. To improve on this situation, we fundamentally look at the design of sharded resilient systems. We do so by introducing BYSHARD, a unifying framework for the study of sharded resilient systems. Within this framework, we show how two-phase commit and two-phase locking ---two techniques central to providing atomicity and isolation in traditional sharded databases---can be implemented efficiently in a Byzantine environment, this with a minimal usage of costly Byzantine resilient primitives. Based on these techniques, we propose eighteen multi-shard transaction processing protocols. Finally, we practically evaluate these protocols and show that each protocol supports high transaction throughput and provides scalability while each striking its own trade-off between throughput, isolation level, latency , and abort rate. As such, our work provides a strong foundation for the development of ACID-compliant general-purpose and flexible sharded resilient data management systems.

Download Full-text

Integrated process for potassium sulfate and a mixture Of ammonium chloride/potassium sulfate salts production

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i1.9188 ◽

2018 ◽

Vol 7 (1.8) ◽

pp. 185 ◽

Cited By ~ 1

Author(s):

Yousef Mubarak

Keyword(s):

Ammonium Chloride ◽

Mother Liquor ◽

Total Yield ◽

Complex Salt ◽

Operating Conditions ◽

Potassium Sulfate ◽

Water Evaporation ◽

Crystallization Time ◽

Sulfate Salts ◽

Evaporation Stage

Relatively pure and coarse crystalline potassium sulfate of about 52 wt % K2O content and almost chlorine free has been obtained by reacting commercial potassium chloride and commercial ammonium sulfate in a stirred tank reactor at moderately low temperature. To increase the yield of potassium sulfate to a reasonable value, an evaporation stage located between the reactor and the crystallizer is used. The main steps of the production process include dissolution, reaction, evaporation, crystallization, centrifuging, drying, and then cooling. It is found that the best operating parameters to produce potassium sulfate of good quality, quantity, and crystal size are 1:1 as KCl/ (NH4)2SO4 mole ratio, 60 ºC reaction temperature, 1 hour reaction time, about one third of the total water used in the dissolution step is to be evaporated, 10 ºC crystallization temperature, 1 hour crystallization time, and 160 and 60 rpm agitation speeds in the reactor and the crystallizer respectively. Applying these operating conditions, a potassium sulfate yield of about 78 % can be achieved. Also, a fully soluble complex salt as a mixture of ammonium chloride and potassium sulfate is obtained by further treatment of the mother liquor. Further concentration of the mother liquor by further water evaporation of about 40 wt % and then crystallization of the slurry at 25 oC can recover up to about 60 wt % of the remaining solid in the mother liquor as a complex salt. The total yield of potassium sulfate is found to be about 95 wt % and the whole value of the solid product obtained is about 79 wt %.

Download Full-text

Enantioselective Diels–Alder reaction of anthracene by chiral tritylium catalysis

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.15.129 ◽

2019 ◽

Vol 15 ◽

pp. 1304-1312 ◽

Cited By ~ 3

Author(s):

Qichao Zhang ◽

Jian Lv ◽

Sanzhong Luo

Keyword(s):

Lewis Acid ◽

Acid Catalyst ◽

Alder Reaction ◽

Ion Pair ◽

Diels Alder ◽

Highly Active ◽

Diels Alder Reaction ◽

New Type ◽

Lewis Acid Catalyst ◽

Trityl Cation

The combination of the trityl cation and a chiral weakly coordinating Fe(III)-based bisphosphate anion was used to develop a new type of a highly active carbocation Lewis acid catalyst. The stereocontrol potential of the chiral tritylium ion pair was demonstrated by its application in an enantioselective Diels–Alder reaction of anthracene.

Download Full-text

Two-phase photometric ion-pair titrations of drugs and surfactants

Analytical Chemistry ◽

10.1021/ac50053a040 ◽

1980 ◽

Vol 52 (3) ◽

pp. 553-557 ◽

Cited By ~ 25

Author(s):

Hussain Y. Mohammed ◽

Frederick F. Cantwell

Keyword(s):

Ion Pair ◽

Two Phase

Download Full-text

Thinking activity-based work environment throughout situated acceptance

Journal of Workplace Learning ◽

10.1108/jwl-02-2020-0027 ◽

2020 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Chiara Lai ◽

Marc-Eric Bobillier Chaumon ◽

Jacqueline Vacherand-Revel ◽

Audrey Abitan

Keyword(s):

Design Stage ◽

Psychological Consequences ◽

Two Phase ◽

Content Type ◽

Four Dimensions ◽

The Social ◽

Real Estate Projects ◽

Acceptance Model ◽

Situated Approach ◽

Do So

Purpose This paper aims to focus on activity-based workplaces, which offer a diversity of typologies and configurations which, instead of being attributed to users, are shared according to the needs of their activities. Indeed, this paper questions the way these activity-based workplaces configure the ways in which individuals and collectives carry out their activity. Design/methodology/approach To do so, this paper established a two-phase methodology. Three days of observation amid three different units evolving in activity-based workplaces have helped us to identify the uses that emerged from these spatial typologies. Then, a set of two interviews with eight participants have been conducted based on the four dimensions of the situated acceptance model (Bobillier Chaumon, 2013) and on picture elicitation. Findings The results allow us to understand how activity-based workspaces can be considered as artefacts for the activity that needs to be appropriated to allow the worker to realise his activity. Research limitations/implications The results provide an overview of the social and psychological consequences of activity-based workspaces on workers, their work collective and their activity. Thus, the conclusions can be mobilised in activity-based real estate projects, for example, during the design stage. Originality/value This research conducted with a situated approach based upon the study of the development of the activity proposes a change from the usual managerial approach about these activity-based workplaces, which prescribe an ideal way of working within the workplace.

Download Full-text

Highly Efficient, Tripodal Ion-Pair Receptors for Switching Selectivity between Acetates and Sulfates Using Solid–Liquid and Liquid–Liquid Extractions

International Journal of Molecular Sciences ◽

10.3390/ijms21249465 ◽

2020 ◽

Vol 21 (24) ◽

pp. 9465

Author(s):

Marta Zaleskaya ◽

Łukasz Dobrzycki ◽

Jan Romański

Keyword(s):

Binding Sites ◽

Liquid Extraction ◽

Ion Pair ◽

Anion Binding ◽

Binding Modes ◽

Anion Receptor ◽

X Ray ◽

Liquid Liquid Extraction ◽

Solid Liquid Extraction ◽

Solid Liquid

A tripodal, squaramide-based ion-pair receptor 1 was synthesized in a modular fashion, and 1H NMR and UV-vis studies revealed its ability to interact more efficiently with anions with the assistance of cations. The reference tripodal anion receptor 2, lacking a crown ether unit, was found to lose the enhancement in anion binding induced by presence of cations. Besides the ability to bind anions in enhanced manner by the “single armed” ion-pair receptor 3, the lack of multiple and prearranged binding sites resulted in its much lower affinity towards anions than in the case of tripodal receptors. Unlike with receptors 2 or 3, the high affinity of 1 towards salts opens up the possibility of extracting extremely hydrophilic sulfate anions from aqueous to organic phase. The disparity in receptor 1 binding modes towards monovalent anions and divalent sulfates assures its selectivity towards sulfates over other lipophilic salts upon liquid–liquid extraction (LLE) and enables the Hofmeister bias to be overcome. By changing the extraction conditions from LLE to SLE (solid–liquid extraction), a switch of selectivity from sulfates to acetates was achieved. X-ray measurements support the ability of anion binding by cooperation of the arms of receptor 1 together with simultaneous binding of cations.

Download Full-text

Investigation of Effects of Baffle Configuration on the Performance of a Fixed-Cone Valve by Gas-Liquid Two-Phase Model

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.166-169.1824 ◽

2012 ◽

Vol 166-169 ◽

pp. 1824-1829

Author(s):

W.L. Wei ◽

B. Lv ◽

Y.L. Liu ◽

X.F. Yang

Keyword(s):

Numerical Simulation ◽

Energy Dissipation ◽

Turbulent Flow ◽

Average Velocity ◽

Simulation Method ◽

Velocity Fields ◽

Two Phase ◽

Pressure Fields ◽

New Type ◽

Conventional Type

Nested type Fixed-Cone Valve, numerical simulation, energy dissipating, turbulent flow Abstract: In this paper, In this paper, a new type of Fixed-Cone Valve was proposed by improving the conventional type Fixed-Cone Valve .The flow fields of the two kinds of Fixed-Cone Valves were studied by using numerical simulation method .The computed pressure fields and the velocity fields were analyzed ,which shows that under the same conditions ,and by using the nested Fixed-Cone valve, the pressure of the upstream pipe and the cone valve and the average velocity along the downstream pipeline are reduced ,but the rate of energy dissipation is increased.

Download Full-text