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Bromine (Br) can usually be found as a bromide (Br‾) form contained in drinking water. Bromate (BrO 3 ‾) formation often occurred during the ozonation process in the presence of Br‾. BrO 3 ‾ is classified as a potential human carcinogen, so both the Br‾ and BrO 3 ‾ concentrations must be strictly controlled before and after an ozone-based treatment procedure, respectively. This work reports on distance-based paper analytical devices (dPADs) that have been modified with silver hexagonal nanoprisms (AgNPrs) for highly sensitive and selective determination of both Br‾ and BrO 3 ‾. The measurement of BrO 3 ‾ is based upon its conversion to bromine vapor (Br 2) when gauged with a paper-based headspace extractor (PAD-HS) that is coupled with dPADs (PAD-HS-dPADs). For Br‾ analysis, O 2 plays an important role in the change from Br‾ to Br 2 within an acid media. Br 2 changes rapidly in water to give us HBrO which is a strong oxidizing agent of AgNPrs. Then, the oxidative reaction of the AgNPrs (pink color) within the presence of Br‾ and BrO 3 ‾ establishes both silver bromide (AgBr) and the silver nanosphere (AgNPs, yellow color), which can then be easily observed as a change of a pink color band to a yellow color band by the naked eye. Quantification of Br‾ and BrO 3 ‾ is then achieved by measuring the length of the yellow color band. Under the optimal conditions, the calibration curve will be linear in the range of 25 μg L−1 to 2 mg L−1, and from 0.5 to 50 μg L−1 for Br‾ and BrO 3 ‾, respectively. The naked-eye detection limits were found to be 10 and 0.5 μg L−1 for Br‾ and BrO 3 ‾, respectively. The proposed dPADs for the Br‾ and BrO 3 ‾ detection exhibited an exceptional sensor performance combined with a low detection limit. They also have the benefits of ease of use, an instrument-free convenience, coupled with portability and a low-cost efficiency. Consequently, our sensing device should be applied to the low-level detection of Br‾ and BrO 3 ‾ in real samples, including drinking water, rice, and flour. Image 1 • The dPAD was developed for highly sensitive and selective multi-analytical detection by the naked eye. • Paper-based headspace extraction has been coupled with dPAD for BrO 3 ‾ detection at a low concentration. • Quantitative determination of Br‾ and BrO 3 ‾ is achieved by an instrument-free process. • Our sensing device was successfully applied to low-level detection of Br‾ and BrO 3 ‾ in real samples. [ABSTRACT FROM AUTHOR]

[Display omitted] • Separation and extraction of brominated salts by crystallization from wastewater. • Solubility was measured of the NaCl-NH 4 Cl-NaBr-NH 4 Br-H 2 O system at 298 K and 323 K. • The solubility of the NaCl-NH 4 Cl-NaBr-NH 4 Br-H 2 O system at 298 K was calculated. • The separation of bromide by crystallization was experimentally verified. Brominated wastewater from the propyl bromide pesticide production rich in ammonium, sodium and bromine salts at a high concentration of 11 %. For the recycling of chemical resources of this mixed brine salt system, this paper proposes a method for the separation of bromide from bromine-containing chemical wastewater by crystallization. According to the process design needs of the new method, and because 298 K and 323 K are two common temperatures in industrial practice, in this paper, the solubility data of the NaCl-NH 4 Cl-NaBr-NH 4 Br-H 2 O quaternary system at 298 K and 323 K, as well as its ternary subsystems, NaBr-NH 4 Br-H 2 O and NH 4 Cl-NH 4 Br-H 2 O at 323 K were determined by the isothermal solubilization method, and the corresponding phase diagrams were drawn. The solubility of the NaCl-NH 4 Cl-NaBr-NH 4 Br-H 2 O quaternary system at 298 K was also calculated using the Pitzer model, and the calculated results were in good agreement with the experimental measurements. Finally, based on the theoretical analysis of the phase diagrams of the 298 K and 323 K NaCl-NH 4 Cl-NaBr-NH 4 Br-H 2 O quaternary systems and combined with the phase diagrams of the 298 K NaBr-NaCl-CH 3 OH system, this paper proposes and designs a salt extraction process route for the brominated wastewater of the propyl bromide pesticide production. Through the separation experiment, the new process proved to be technically feasible and produced NaCl with 100 % purity, Na(Br,Cl) with 98.23 % NaBr, and NH 4 (Cl,Br) with 99.18 % and 97.57 % NH 4 Cl, respectively. The new process realizes the resourceful utilization of bromine-containing wastewater, and has the significant advantages of production safety and no emission of three wastes. [ABSTRACT FROM AUTHOR]

The distribution of acid sites in Mordenite (MOR) is crucial for its carbonylation performance. In this paper, MOR was subjected to acid treatment to selectively remove acid sites in 12 member-ring (MR) with the assistance of tetraethylammonium bromide (TEABr) used during synthesis process. The impact of acid treatment on structure, morphology, framework atoms and acidity were systematically studied. The characterization results indicated that the structure of the samples was only slightly impacted while the mesopore volume slightly increased. Due to the excessive removal of acid sites, the sample treated by nitric acid (0.1 mol/L) exhibited lower carbonylation activity whether with or without the protection of templates. However, the acid sites in the 12 MR were selectively removed in the citric acid treatment process by two different ways: the etching effect of H+ and the complexation of citric ions. The protection effect of templates for the acid sites in 8 MR was remarkable. Therefore, selective removal of acid sites in 12 MR was successful realized with assistance of template, leading to considerable improvements in activity for DME carbonylation reaction. [Display omitted] • Acid sites in 12 MR were selectively removed by acid treatment. • Templates could protect acid sites in 8 MR. • Samples treated with citric acid showed better activity for carbonylation reaction. [ABSTRACT FROM AUTHOR]

In order to avoid secondary pollution during recovery of brominated resin, additives had been proposed for capturing bromine in high-temperature (700 °C) pyrolysis of brominated resin. However, the capture capacity and mechanism of CaCO 3 and activated carbon to the generated micromolecule bromides was still unknown in the low-temperature (300 °C) pyrolysis process, in which brominated resin could realize debromination. This paper accurately analyzed the capture capacity and mechanism of CaCO 3 and activated carbon to bromides by quantum chemistry calculation and wet experiments. CH 3 Br was considered as the main bromide in the low-temperature pyrolysis. The capture process of CaCO 3 to CH 3 Br turned to be physisorption, and one CaCO 3 particle with the size of 0.5 μm could captured 4.53 × 10−22 mol CH 3 Br. The capture capacity of CaCO 3 to CH 3 Br is only 2.37 × 10−9 mol/g. Furthermore, the capture capacity of activated carbon to CH 3 Br was 8.50 × 10−5 mol/g. The mass of activated carbon needed to capture 4.03 × 10−4 mol CH 3 Br generated of 1 g brominated resin in low-temperature pyrolysis was 3.68 g. This paper contributes scientific information and approach to the safe resource recovery of waste brominated resin. [Display omitted] • The thermogravimetric characteristic of brominated resin with CaCO 3 was studied. •Quantum chemistry calculation was applied to simulate the capture process. •Physical capture of CaCO 3 to bromides at low-temperature was determined. •Feasibility of activated carbon capturing bromides at low-temperature was analyzed. [ABSTRACT FROM AUTHOR]

Abstract Alternative disinfection technologies may overcome some of the limitations of conventional treatment applied in swimming pools: chlorine-resistant pathogens (e.g. Cryptosporidium oocysts and Giardia cysts) and the formation of chlorinated disinfection byproducts. In this paper, results of full scale validation of an alternative disinfection technology UVOX Redox® (hereinafter referred to as UVOX) that combines ozonation and UV irradiation are presented. The performance was assessed in terms of microbial inactivation, disinfection byproduct formation and micropollutant removal. UVOX was able to achieve 1.4–2.7 log inactivation of Bacillus subtilis spores at water flows between 20 and 76 m³/h. Lower formation of trichloromethane and dichloroacetic acid was observed with UVOX followed by chlorination when compared to chlorination alone. However, due to the use of ozone and the presence of bromide in the pool water, the formation of trihalomethanes and haloacetic acids shifted to more brominated byproducts. Chlorine alone was able to remove the target micropollutants: acetaminophen, atenolol, caffeine, carbamazepine, estrone, estradiol, and venlafaxine (>97% removal) after 24 h, with the exception of ibuprofen (60% removal). The application of UVOX in chlorinated water enhanced the removal of ibuprofen. The application of UVOX could lower the usage of chlorine to the level that provides an adequate residual disinfection effect. Highlights • UVOX technology can inactivate chlorine-resistant microorganisms. • In chlorinated pool water, UVOX influenced the formation of brominated DBPs. • Removal of the selected micropollutants was largely due to chlorination. • UVOX enhanced the removal of ibuprofen in chlorinated water. [ABSTRACT FROM AUTHOR]

Abstract In this paper, the continuation of our work on searching for anti-crystallization additives to the aqueous solution of lithium bromide is presented. This type of research is important from the viewpoint of absorption refrigeration technology to improve the performance of the efficiency of refrigeration equipment. In this study, three crown ethers: 12-crown-4, 15-crown-5, and 18-crown-6 as well as the glycols: ethylene glycol, diethylene glycol, triethylene glycol and glycerol were investigated as anti-crystallization additives for {LiBr (1) + water (2)} system, conventionally used as a working pair in absorption refrigeration technology. For this purpose, the solubility of lithium bromide in water has been determined in the presence of the organic additive. The solubility measurements have been carried out using a dynamic method at a wide temperature and composition range for different (additive to LiBr) initial mass fraction from w 2 0 = 0.1, 0.2 and 0.3. From experimental SLE data, the comparison range of the liquid state for tested systems at the absorber's working temperature was determined and compared to those from conventional (LiBr + water) system. Further measurements of vapor – liquid equilibria will be performed to select the best anti-crystallization additive. Highlights • Crown ethers and glycols have been investigated as an anti-crystallization additive for (LiBr + water) system. • The experimental data on solubility of {LiBr (1) + additive (2) + water (3)} at a wide temperature and composition range were presented. • Based on the SLE data anty-crystallization additive was chosen. [ABSTRACT FROM AUTHOR]

Abstract In this paper we study a role of F-centers, hole centers and excitons in energy transfer in Eu-doped BaBrI crystals. Optical absorption spectra, thermally stimulated (TSL) and photostimulated (PSL) luminescence in wide temperature range 7–300 K are studied in undoped and doped with different concentrations of Eu ions BaBrI crystals. Based on experimental and calculated results two possible energy tranfer processes from host to Eu2+ ions are established. Highlights • Two possible energy tranfer processes from BaBrI host to Eu2+ ions are established. • Fast resonance energy transfer from STE to Eu2+ takes place. • Absorption bands in irradiated crystals at about 2–2.5 eV are attributed to F(Br)-center. • Ab initio calculation of F-centers in BaBrI was performed. [ABSTRACT FROM AUTHOR]

Abstract In this paper, a series of protonated titanate nanotubes (PTNTs) modified by stearyl trimethyl ammonium bromide (STAB) were prepared as supports for Polyethyleneimine (PEI)-based sorbents. The CO 2 adsorption performance was evaluated in a self-assembled fixed bed reactor. The typical sorbents were characterized by XRD, EDS, SEM, HR-TEM, N 2 adsorption-desorption, FT-IR and TGA. Results indicate that the modification significantly improves CO 2 adsorption capacity of the sorbents. The maximum CO 2 adsorption amount of 2.22 mmol/g was obtained over the modified PEI-based sorbent in 2% CO 2 /air. Based on the characteristic analysis, the formation of creviced nanotubes, instead of intact nanotubes, is testified because of the modification. Such unique nanotubes possess the higher BET surface area and larger pore volume, which enables more PEI to uniformly distribute on the surface of modified PTNT supports. Especially, it is easier for PEI to enter the inner pores through the crevice than from tube orifices, avoiding pore blockage and facilitating CO 2 diffusion in pores. The abundant amine-sites and small internal diffusion resistance endow the modified sorbent with large CO 2 adsorption capacity. In addition, the PEI/PTNT adsorbent displays good thermal stability and reusability. Graphical abstract Image 1 Highlights • Creviced nanotubes instead of intact nanotubes are formed after introducing stearyl trimethyl ammonium bromide. • The formation of the creviced nanotubes is favorable for the exposure of amine-sites. • The increased accessible amine-sites on the modified nanotubes improve the CO 2 adsorption. • The modified amine-based sorbents display good thermal stability and reusability. [ABSTRACT FROM AUTHOR]

Highlights • Exergy analysis on direct and indirect fired single to triple effect cycles. • Optimization of operating parameters for maximum performance. • Comparison of system performance for direct and indirect fired cycles. • Optimum operating parameters for direct fired absorption cycles are presented. Abstract This paper deals with a review on exergy analyses of lithium bromide-water based single to triple effect direct and indirect fired vapour absorption systems. The analysis carried out by various investigators on exergy of the absorption cycles have been discussed. To fill the gap in the knowledge on exergy destruction rate in the absorption system, optimization of the single to triple effect direct and indirect fired absorption cycles have been conducted for a wide range of operating conditions. Hence optimum parameters in various components of the systems for maximum exergy coefficient of performance and minimum exergy destruction rate have been determined. The indirect fired systems have been optimized for different temperatures of the energy source related to the main generator temperature. While the direct fired systems have been optimized considering exergy destruction rate during the combustion process of energy sources. The energy sources selected in the present analysis are compressed natural gas and liquefied petroleum gas. Double effect cycle yields better exergy performance when the difference in temperatures of the energy source and the generator is between 6 to 37 °C, while triple effect cycle performs well when it is beyond 37 °C. [ABSTRACT FROM AUTHOR]

This paper reports the synthesis of 2-(4-hydroxyphenyl)ethyl and 2-(4-nitrophenyl)ethyl substituted benzimidazolium salts. The benzimidazolium salts were synthesized by N-substituted benzimidazolium and aryl halides. The 2-(4-hydroxyphenyl)ethyl and 2-(4-nitrophenyl)ethyl substituted benzimidazolium salts were characterized by using 1 H NMR, 13 C NMR, FT-IR spectroscopy and elemental analysis techniques. Molecular and crystal structure of the complex 2d and 3d were obtained by single-crystal X-ray diffraction method. Additionally, The enzyme inhibition activities of the benzimidazolium salts were investigated. These 2-(4-hydroxyphenyl)ethyl and 2-(4-nitrophenyl)ethyl substituted benzimidazolium salts (1, 2a-g, and 3a-f) showed good inhibitory action against acetylcholinesterase (AChE), and human (h) carbonic anhydrase (CA) isoforms I, and II. Ki values for AChE were in range of 5.97 ± 0.56–23.15 ± 3.98 nM. On the other hand, the hCA I, and II isoenzymes were effectively inhibited by these compounds, with K i values in the range of 17.33 ± 4.55–99.23 ± 44.91 nM for hCA I, and 33.98 ± 3.43–113.23 ± 39.31 nM for hCA II, respectively. [ABSTRACT FROM AUTHOR]

The paper describes the determination of bromide by evaluating the molecular absorption of thallium mono-bromide (TlBr) at the rotational line at 342.9815 nm by making use a high-resolution continuum source graphite furnace atomic absorption spectrometer. The effects of variables such as the wavelength, graphite furnace program, amount of Tl and the use of a modifier were investigated and optimized. Various chemical modifiers have been studied, such as Pd, Mg, Ag and a mixture of Pd/Mg. It was found that best results were obtained by using Ag which prevents losses of bromide during pyrolysis step through precipitation of bromide as AgBr. In this way, a maximum pyrolysis temperature of 400 °C could be used. The optimum molecule forming temperature was found to be 900 °C. Bromide concentrations in various water samples (CRM, bottled drinking water and tap water) were determined. The quantification was made by both linear calibration and standard addition techniques. The results were matched well those of the reference method. The calibration curve was linear in the range between 1 and 1000 ng Br with a correlation coefficient R = 0.999. The limit of detection and characteristic mass of the method were 0.3 ng and 4.4 ng of Br. [ABSTRACT FROM AUTHOR]

Thallium bromide (TlBr) is an attractive semiconductor material for fabrication of radiation detectors due to its high photon stopping power originating from its high atomic number, wide band gap and high resistivity. In this paper the vertical Bridgman method was used for crystal growth and TlBr single crystals with diameter of 15 mm were grown. X-ray diffraction (XRD) was used to identify phase and orientation. Electron backscatter diffraction (EBSD) was used to investigate crystal microstructure and crystallographic orientation. The optical and electric performance of the crystal was characterized by infrared (IR) transmittance spectra and I-V measurement. The types of point defects in the crystals were investigated by thermally stimulated current (TSC) spectra and positron annihilation spectroscopy (PAS). Four types of defects, with ionization energy of each defect fitting as follows: 0.1308, 0.1540, 0.3822 and 0.538 eV, were confirmed from the TSC result. The PAS result showed that there were Tl vacancies in the crystal. [ABSTRACT FROM AUTHOR]

An optimal process configuration for double-effect water-lithium bromide absorption refrigeration systems with series flow – where the solution is first passed through the high-temperature generator – is obtained by minimization of the total annual cost for a required cooling capacity. To this end, a nonlinear mathematical programming approach is used. Compared to the optimized conventional double-effect configuration, the new optimal configuration obtained in this paper allows reducing the total annual cost, the capital expenditures, and the operating expenditures by around 9.5%, 11.1% and 4.9%, respectively. Most importantly, the obtained optimal solution eliminates the low-temperature solution heat exchanger from the conventional configuration, rendering a new process configuration. The energy integration between the weak and strong lithium bromide solutions (cold and hot streams, respectively) takes place entirely at the high-temperature zone, and the sizes and operating conditions of the other process units change accordingly in order to meet the problem specification with the minimal total annual cost. This new configuration was obtained for wide ranges of the cooling capacity (150–450 kW) and the temperature of the cooling water (15–35 °C). The results of this work motivate to apply the simultaneous optimization approach to seek for new multi-effect absorption refrigeration system configurations with parallel and reverse flow as well as other series flow arrangements that minimize the total annual cost. [ABSTRACT FROM AUTHOR]

Single effect, lithium bromide absorption chillers offer the ability to utilize low-pressure steam to produce chilled water for satisfying various comfort cooling needs. Previous attempts have been made to characterize dynamic and steady-state absorption chiller operation. Though these models perform adequately, they are based on hot water driven absorption chillers. Commercially available absorption chillers often can run on both hot water and low-pressure steam. In this paper, the mathematical framework for a dynamic single effect, lithium bromide absorption chiller model capable of using low-pressure steam is presented. The transient thermodynamic FORTRAN model is grounded on mass, energy, and species balances, and builds on prior modeling efforts. Well-known correlations for heat transfer coefficients are used to describe both tube-side and shell-side heat transfer rates in each primary chiller component. To account for the absorption chiller unit receiving steam, a heat transfer model for condensation inside horizontal tubes based on distinct internal condensation flow regimes is incorporated within the generator. This heat transfer model is used with two-phase flow pressure drop equations to establish steam temperature, quality, and pressure along the generator tube bundle. Steam consumption trends are established as a function of fluctuating external conditions. These trends reasonably align with information made available online by the manufacturer, though some deviation does occur at low chiller capacities and cooling water temperatures. Additionally, the transient response of internal and external parameters from a step increase in heat input supplied to the generator mimics results of other dynamic absorption chiller models found throughout literature. [ABSTRACT FROM AUTHOR]

This work explored the spectroscopic parameters and vibrational properties of 12 states of BrO radical. The 12 states were X 2 Π, A 2 Π, 1 2 Δ, 1 2 Σ + , 1 2 Σ − , 2 2 Σ − , a 4 Σ − , 2 4 Σ − , 1 4 Σ + , 1 4 Δ, 1 4 Π, and 2 4 Π, which were generated from the first dissociation limit, Br( 2 P u ) + O( 3 P g ). The potential energy curves were calculated with the CASSCF method, which was followed by the icMRCI approach with Davidson correction. Of the 12 electronic states, the 2 4 Π state was repulsive. Each state had the single well and only the A 2 Π state had one barrier. The 1 2 Δ, 1 2 Σ + , 1 2 Σ − , 2 2 Σ − , 2 4 Σ − , 1 4 Σ + , 1 4 Δ and 1 4 Π states had only several vibrational levels and were very weakly-bound states, which well depths were less than 110 cm −1 . To improve the quality of potential energy curves, core-valence correlation and scalar relativistic corrections as well as the extrapolation to the complete basis set limit were included. The spectroscopic parameters and vibrational properties were determined. The transition dipole moments between two electronic states and Franck-Condon factors of some transitions were evaluated. The spin-orbit coupling effect on the spectroscopic parameters of the X 2 Π and A 2 Π states was discussed. The spectroscopic parameters and vibrational properties reported in this paper can be expected to be reliably predicted ones. [ABSTRACT FROM AUTHOR]

In this paper, we report gas-liquid partition constants for thirty-five volatile organic solutes in the room temperature ionic liquid trihexyl(tetradecyl)phosphonium bromide measured by gas-liquid chromatography using capillary columns. The relative contribution of gas-liquid partition and interfacial adsorption to retention was evaluated through the use of columns with different the phase ratio. Four capillary columns with exactly known phase ratios were constructed and employed to measure the solute retention factors at four temperatures between 313.15 and 343.15 K. The partition coefficients were calculated from the slopes of the linear regression between solute retention factors and the reciprocal of phase ratio at a given temperature according to the gas-liquid chromatographic theory. Gas-liquid interfacial adsorption was detected for a few solutes and it has been considered for the calculations of partition coefficient. Reliable solute's infinite dilution activity coefficients can be obtained when retention data are determined by a unique partitioning mechanism. The partial molar excess enthalpies at infinite dilution have been estimated from the dependence of experimental values of solute activity coefficients with the column temperature. A thorough discussion of the uncertainties of the experimental measurements and the main advantages of the use of capillary columns to acquire the aforementioned relevant thermodynamic information was performed. [ABSTRACT FROM AUTHOR]

This paper analyzes the potential of heat recovery and the manner in which the power delivered by the solar panels can be used, in cold season, for a lithium-bromide absorption system with the heat generator driven by natural gas or/and solar energy. The reasearch were conducted on an experimental stand located in the Department of Heat Engineering and Thermal Equipment Laboratory, Bucharest. In order to evaluate the system's performance, the authors have studied the operation conditions for cold season, and the opportunity of using the heat recovered in the condenser and absorber to heat the air in a heating coil. [ABSTRACT FROM AUTHOR]

The application of metal nanoparticles (NPs) in catalysis has drawn significant research interest, including in their applications to the wastewater treatment. Nanocellulose can be a versatile support/carrier in stabilizing metal NPs catalysts, due to its unique properties. In this paper, hexadecyl-trimethylammonium bromide (CTAB) surfactant-adsorbed cellulose nanocrystals (CNC) was employed as a support for silver nanoparticles (Ag NPs). The obtained CNC/CTAB/Ag nanohybrid composite was characterized by ultraviolet–visible (UV–vis) spectroscopy, transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). The results of the catalytic reaction experiments showed that Ag NPs immobilized on CTAB-adsorbed CNC displayed higher catalytic efficiency towards the reduction of 4-nitrophenol to 4-aminophenol, compared to the control Ag NPs and CNC/Ag samples. The enhanced catalytic performance of Ag NPs was attributed to the improved dispersity and narrow distribution of silver nanoparticles in the catalytic system. This work provides a novel catalyst based on CNC-CTAB stabilized Ag NPs which would have promising applications towards catalytic treatment of wastewater. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to study the molecular dynamics simulation of phosphorus tribromide (PBr 3 ) as the condensed inorganic liquid. To this aim, four regional intermolecular potential functions of phosphorus tribromide in the gas phase were considered. The potential energy data of 9 phosphorous tribromide configuration dimers were calculated at the B3LYP/6-31 + G (d) level of theory. The calculated potential data were employed to construct a 4-site all-atom force field model. Then, the force field parameters were used to perform the molecular dynamics simulations and compared the simulation results with experimental data. Quantitative agreements for the atomic number density, internal energy, enthalpy, heat capacity and radial distribution function over a wide range of experimental conditions were obtained as a consequence of the parameters force field validation without using experimental data a priori. [ABSTRACT FROM AUTHOR]

The property of vapor pressure above aqueous solution of lithium bromide has been extensively studied, but the experimental data are mostly limited to temperature range above 0°C. During recent years novel applications of hygroscopic solutions at subzero temperatures were proposed; thus more accurate data of vapor pressure are anticipated. In this paper the equilibrium vapor pressure above aqueous LiBr solution was measured with static method in the temperature range from 217K to 273K. The molality of LiBr varied from 8.62 to 11.51 mol kg −1 . The measured data were compared with the calculated values of an existing formulation (Pátek and Klomfar in 2006), and a mean deviation of 35.85% was found. If the data were correlated with a modified Antoine equation, a mean deviation of 2.81% could be obtained. In order to estimate the hygroscopic potential of low temperature aqueous LiBr solution as compared to cold surface, the temperature differences between the solution and the ice at the same vapor pressures were estimated. [ABSTRACT FROM AUTHOR]

This paper presents the effect of methanol (MeOH) on the micellization of cetyltrimethylammonium bromide (CTAB) containing different concentrations of Furosemide (cardiovascular drug). Taking into account the advantages of surfactant micelles as carriers, the influence of Furosemide on CTAB micellar system has been studied in methanol–water mixtures. The physico-chemical interactions between drug and surfactant were characterized by using conductometric as well as the density and speed of sound measurements. From these experimental measurements, the critical micelle concentration ( CMC ), standard Gibbs energy (Δ G m o ), enthalpy (Δ H m o ), entropy (Δ G m o ) of micellization, apparent molar volume ( ϕ v ) and apparent molar adiabatic compressibility ( ϕ k ) have been calculated. The micellization of CTAB in water–methanol–drug medium has been found to depend on nature as well as the concentration of Furosemide. The critical micelle concentration values tend to decrease with increase in Furosemide content. The tendency of alcohols to modify solvent structure and penetration of drug into the micelles has been used to interpret their effects on micellization of CTAB. [ABSTRACT FROM AUTHOR]

• Calcium bromide was used to improve the early strength of mortar mixed with alkali free liquid accelerator. • It is proved that Ca 4 Al 2 O 6 Br 2 ·10H 2 O phase is the main reason to promote the early strength of mortar. • A theoretical model of the synergistic effect of calcium bromide and alkali free liquid accelerator is proposed. This paper investigated the influence mechanism of CaBr 2 on the early strength of mortar mixed with the alkali-free liquid accelerator. The results showed that the final setting time was shortened from 6.5 to 5.58 min, and the compressive strength of 1 d, 3 d, and 7 d increased by 42.7%, 28.96%, and 32.47%, when the dosage of CaBr 2 was 1.5%. Meanwhile, the hydration products were further investigated in CaBr 2 -C 3 A-H 2 O, CaBr 2 -C 3 A-Gp-H 2 O, and CaBr 2 -C 3 A-Gp-AF-H 2 O systems. By XRD and Raman analysis, it was determined that CaBr 2 could form a new phase Ca 4 Al 2 O 6 Br 2 ·10H 2 O with C 3 A in different systems. Combined with the setting time and the compressive strength test results, it was concluded that Ca 4 Al 2 O 6 Br 2 ·10H 2 O phase was the main factor in improving the early strength and shortening the setting time. Moreover, a conceptual model of CaBr 2 hydration was proposed to analyze the hydration process. [ABSTRACT FROM AUTHOR]

This work is part of a larger study dedicated to an inter-seasonal heat storage process based on novel absorption pump operated in two half-cycles that uses LiBr/H 2 O as the absorbent/absorbate couple. The solar energy is stored during summer through desorption, and the heat is released during winter through absorption. A characteristic of the device is that crystallization occurs in the storage tank as its temperature falls under 10 °C at the end of summer or in winter. Thus, information on the degree of hydration of the crystals at low temperature is required to optimize the storage density. This paper aims to precisely determine the behavior of LiBr in terms of crystallization. In this study, solubility and metastable zone limit curves were assessed using an agitated and thermostated batch crystallizer. A video sensor was employed for assessment of the crystals morphology and thus, the hydrated crystalline forms present inside. The transition temperature between lithium bromide dihydrate and trihydrate was found to be equal to 3.0 °C. The dissolution and crystallization enthalpies were also calculated using the Van׳t Hoff plot, and results were found to be in good agreement with the literature data. [ABSTRACT FROM AUTHOR]

This paper discusses the formation of cetylpyridinium bromide (CPB), a cationic surfactant quaternary ammonium compound (QAC), immobilized on kaolinite with different initial CPB concentrations ([CPB] i ) and their effect on the antibacterial activity against Escherichia coli . The CPB-immobilized kaolinites were characterized by a CHNS analyzer, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), zeta potential (ZP) analysis and the amount of CPB adsorbed on kaolinite. The antibacterial assay of the samples was studied through the disk diffusion technique (DDT) against E. coli as a model bacterium. The amount of CPB adsorbed on kaolinite did not affect the structure of the parent kaolinite but affected the overall charge of the kaolinite and eventually affected their antibacterial activity. CPB-immobilized kaolinite with [CPB] i above the critical micelle concentration (CMC) possessed antibacterial activity because of reversal of the charge from negative to positive on the kaolinite surfaces, as proven by ZP analysis, which could allow the action of CPB molecules against bacteria cells. This was due to the bilayer formation of surfactant molecules via hydrophobic bonding of their long hydrocarbon chains on the kaolinite surfaces at surfactant concentrations above the CMC value. Therefore, one of the important factors in producing antibacterial agents from surfactant immobilized kaolinite (organo-clay) is by loading excess surfactant on the clay above its CMC level to ensure bilayer formation of surfactant molecules on clay surfaces. [ABSTRACT FROM AUTHOR]

The aim of the paper is the selective extraction and stripping of Cd(II) from acidic iodide solutions containing Cd(II) and Ni(II) by liquid–liquid solvent extraction technique using synthesized and characterized imidazolium salts as carriers, which are 3-butyl-1-methyl-1H-imidazol-3-ium bromide (IM1), 1,3-dibutyl-1H-midazol-3-ium bromide (IM2), 3-isobutyl-1-methyl-1H-imidazol-3-ium bromide (IM3), 1,3-diisobutyl-1H-midazol-3-ium bromide (IM4), in dichloromethane. The important parameters affecting extraction and stripping behavior of Cd(II) were studied experimentally. Complex formation and its stoichiometric rate between IMs and CdI 4 2− was explained with comparison of ATR-FTIR spectrums of pure and CdI 4 2− (aq) loaded IMs and slope analysis. According to these evaluations, the adduct formation was confirmed as IM 2 CdI 4(org) . In the light of obtained results, the symmetric IMs substituting n -butyl group on nitrogen atoms have been determined as the best appropriate IMs to transport of Cd(II). Under optimum conditions, 99.24% of Cd(II) has been extracted from acidic iodide solution containing 500 mg/L of Cd(II) and Ni(II). Ni(II) extraction percentages were observed as negligible throughout experiments. The extraction selectivity of Cd(II) over the other metal ion impurities has been identified in the order β Cd/Ni > β Cd/Co > β Cd/Zn > β CdCu . [ABSTRACT FROM AUTHOR]

• Quasi-equilibrium character of the oxidative addition of ArCl to Pd was demonstrated. • Quasi-equilibrated oxidative addition cannot be therefore the RDS. • Low reactivity of ArCl is caused by another reason not related to oxidative addition. The retarded oxidative addition of aryl chlorides to palladium is commonly believed to be the main obstacle for their successful conversion in cross-coupling reactions. However, this point has been fairly challenged in several papers, including those published recently, by providing experimental data obtained under both model and real catalytic conditions. Here, we provide proof of the fast and reversible character of the oxidative addition elementary step with aryl chlorides in the catalytic cycle of the Mizoroki-Heck reaction. The results have been obtained by the original kinetic approach using the differential selectivity of the competing Mizoroki-Heck reaction with two aryl chlorides. The kinetic data obtained in the real phosphine-free catalytic system unambiguously disproved the rate-determining character of the oxidative addition of aryl chloride as the key factor for lowering the catalytic activity when using aryl chlorides instead of aryl iodides and aryl bromides in the Mizoroki-Heck reaction. [Display omitted] [ABSTRACT FROM AUTHOR]

This work describes an installation in Madrid, Spain, designed to test a new solar-powered air-cooled absorption refrigeration system. This installation essentially consists of a-48 m 2 field of flat-plate solar collectors, a 1500-L hot water storage tank and a single and-double effect air-cooled lithium bromide absorption prototype. Designed and built by our research group, this prototype is able to operate either as a single-effect unit (4.5 kW) or as a double-effect unit (7 kW). In operation as single-effect mode, the prototype is driven by solar energy, whereas in operation as a double effect mode, an external energy source may be used. The prototype's evaporator is connected to a fan-coil placed inside an 80-m 2 laboratory that represent the average size of a Spanish housing unit. In August 2009, the cooling system was tested in the single-effect operation mode. The results show that the system is able to meet approximately 65% of the laboratory's seasonal cooling demand, although 100% may be reached for a few days. The prototype can also operate in double-effect mode to meet the cooling demand. In that case, the prototype is fed by thermal oil, which is warmed until it reaches the process temperature in the high-temperature generator. The prototype can operate in either single-effect mode or in double-effect mode or can also operate simultaneously both modes using the components common to both modes, namely, the absorber, evaporator, condenser, solution pumps and control equipment. This paper reports the experimental results from the prototype operating separately in single-effect and double-effect mode. [ABSTRACT FROM AUTHOR]

Recent years have seen a renewed interest for molten salt reactor (MSR) technologies. It is noticeable, though, that all MSR projects feature either fluoride or chloride melts for the fuel salt while the use of heavier halides -- bromine and iodine, namely – is scarcely mentioned with the argument that their capture cross section is too high. This paper thus intends to update the status of bromide and iodide salts as potential nuclear salts through a more in depth comparison of these melts with respect to more "standard" fluoride and chloride compounds. A literature review of the main thermodynamic properties of a few sodium halides, uranium halides and plutonium halides is presented to support the potential existence of liquid melts for bromides and iodides. The existence of stable critical neutronic configurations is then discussed showing that both bromide and iodide salts might constitute reasonable candidates for burner cores. The radiotoxicity of most dangerous and/or oxidizing activation products is finally analyzed showing that iodide salts are comparable with their fluoride and chloride analogs. The use of bromide salts, though, leads to an increase in gamma emission. [Display omitted] • The use of various plutonium halides as fuel for a molten-salt reactor was investigated. • Stable configurations were found for all halides, with an increasing critical mass for bromides and iodides. • From a neutronic point of view, the use of heavier halides might be of interest for burner cores. • Experimental data on physico-chemical properties of actinide bromides and iodides is necessary to strengthen the conclusions. [ABSTRACT FROM AUTHOR]

[Display omitted] • A facile approach for the preparation of ortho -bromoanilides was developed. • All starting materials, aryhydroxylamines and thionyl bromide, were readily available. • Structurally diverse ortho -bromoanilides can be prepared in good yields with excellent regioselectivity. • A reaction mechanism involving the intramolecular substitution was proposed. A facile approach for synthesizing ortho -bromoanilides from readily available aryhydroxylamines and thionyl bromide is demonstrated in this work. Mild reaction conditions and broad scope of substrates ranging from heterocyclic structures to pharmaceutics-potential motifs are used in the reactions of this paper. Efficient bromination of ortho C H bonds of the aryhydroxylamines has been achieved. Ortho -bromoanilide products were obtained in good to excellent yields, and model scaled-up reactions of this synthetic approach are shown in this work. [ABSTRACT FROM AUTHOR]

[Display omitted] • The thermoresponsive Pickering emulsion was prepared with SiO 2 nanoparticle modified by AEO-7 and TBAB. • The Pickering emulsion could keep stable under high salinity conditions and demulsified at elevated temperature. • The emulsion showed excellent catalytic performance in esterification reaction. • The Pickering emulsion could be reused at least five times without sacrifice of the catalytic activity. In this paper, a thermo-responsive Pickering emulsion (PE) is constructed for the esterification reaction in the phase transfer catalysis (PTC) system. Silica nanoparticle modified by alkyl polyoxyethylene ether and tetrabutylammonium bromide (TBAB) is the highly efficient thermo-responsive Pickering emulsifier to stabilize the diisopropyl ketone-in-water emulsion. PEs can keep stable at room temperature for 3 days and demulsify only in the condition of elevated temperature and agitation, which causes the easy product separation and aqueous phase recycling. The adsorption of TBA+ and nonionic surfactant via electrostatic interaction and hydrogen bonding, respectively, can increase the hydrophobicity and the emulsifying capacity of silica nanoparticle. The ion-pair of TBA+ and reactant anion is generated and can be transferred into the organic phase, initiating the bond-forming reaction. The modifying effect of polyoxyethylene ether is weakened with the increase of temperature due to the loss of the hydrogen bonding interaction, resulting in the demulsification of PEs. Moreover, the cloud point of polyoxyethylene ether is the temperature for the complete separation of two phases. In this PTC system, the conversion rate for the esterification can reach to 92 % and the aqueous phase can be reused at least 5 times without sacrifice of the catalytic activity, demonstrating the potential application in industry. [ABSTRACT FROM AUTHOR]

In this paper, an electrodialysis regeneration experimental system was set up to evaluate the performance of electrodialysis regeneration system using lithium bromide solution, whose concentration is much higher than that of LiCl solution. The effects of cycling flow rate, initial concentration, and operating current on the current efficiency of the electrodialysis regeneration system using LiBr solution were studied. The current efficiency model and regeneration result model of the electrodialysis regenerator for LiBr solution were acquired based on experimental results. The results show that the ED regenerator can regenerate the LiBr solution reliably, and the current efficiency of the ED regenerator using LiBr solution is lower than that for LiCl solution. To enhance the capability of electrodialysis regenerator, the difference in cycling flow rates between dilute and concentrate chambers should be controlled. The current efficiency of the electrodialysis regenerator and COP of electrodialysis regeneration system decreased with the increase of the operating current and initial concentration. When the concentration of LiBr solution is 45% and the operating current is 3A, the electrodialysis regeneration system has the maximum current efficiency of about 30.365% and the maximum COP of 4.26. • Electrodialysis (ED) regenerator with 30 cell pairs experimental system is set up. • Current efficiency and concentration increase models of LiBr solution are got. • Increasing flow rate can improve performance of ED regenerator and whole system. • Flow rate difference should be controlled to optimize ED regenerator performance. • Excessive initial concentration and operational current are harmful to the system. [ABSTRACT FROM AUTHOR]

An appropriate cellulose-dissolving solvent is critical for the homogeneous oxidation of cellulose using TEMPO (2, 2, 6, 6-tetramethylpiperidine-1-oxyl)-mediated system. Herein, TEMPO/NaClO/NaClO 2 system in lithium bromide hydrates (LBHs) was developed for the homogeneous selective-oxidation of cellulose, which was two-stage protocol involving cellulose dissolution and homogeneous oxidation. Specifically, cellulose was firstly dissolved in LiBr·3.5H 2 O and offered the optimal pH (5.6) for the subsequent TEMPO/NaClO/NaClO 2 oxidation without precipitation of the cellulose chains. Effect of reaction conditions on cellulose oxidation was investigated. The results showed that high degree of oxidation (DO) and evenly distributed carboxyl could be achieved. The particle size gradually decreased with DO, and oxidized cellulose with high water solubility and amorphous structure could be obtained. Furthermore, FT-IR, 13C NMR and fractionation analysis verified that cellulose was successfully converted and the carboxyl uniformly distributed onto the cellulose chains. This TEMPO-mediated system using LBHs as solvent presented an efficient method on the homogeneous selective oxidation of primary hydroxyl in cellulose. [Display omitted] • LiBr·3.5H 2 O was suitable solvent for homogeneous oxidation of cellulose. • Dissolved cellulose was selectively oxidized by TEMPO/NaClO/NaClO 2. • Cellulose at high DO features water solubility and amorphous structure. • Dissolved cellulose with different DP could be homogenously oxidized. [ABSTRACT FROM AUTHOR]