Calculations and Sensitivity Analysis of Chlorine-,NO_(x)-,and Bromine-Depleting Cycles of Stratospheric Ozone

This paper presents an engineering system approach using a 2D model of conservation of mass to study the dynamics of ozone and concerned chemical species in the stratosphere.By considering all fourteen photolysis,ozone-generating,and-depleting chemical reactions,the model calculated the transient,spatial changes of ozone under different physical-chemical-radiative conditions.Validation against the measured data demonstrated good accuracy,close match of our model with the observed ozone concentrations at both 20°S and 90°N locations.The deviation in the average concentration was less than 1% and in ozone profiles less than 17%.The impacts of various chlorine-(Cl),nitrogen oxides-(NO_(x)),and bromine-(Br)depleting cycles on ozone concentrations and distribution were investigated.The chlorine catalytic depleting cycle was found to exhibit the most significant impact on ozone dynamics,confirming the key role of chlorine in the problem of ozone depletion.Sensitivity analysis was conducted with levels of 25%,50%,100%,200%,and 400% of the baseline value.The combined cycles(Cl+NO_(x)+Br)showed the most significant influence on ozone behavior.The total ozone abundance above the South Pole could decrease by a small 3%,from 281 DU(Dubson Units)to 273 DU for the 25% level,or by a huge thinning of 60%to 114 DU for the 400% concentration level.When the level of chlorine gases increased beyond 200%,it would cause ozone depletion to a level of ozone hole(below 220 DU).The 2D Ozone Model presented in this paper demonstrates robustness,convenience,efficiency,and executability for analyzing complex ozone phenomena in the stratosphere.

Zinc–Bromine Rechargeable Batteries:From Device Configuration,Electrochemistry,Material to Performance Evaluation

Zinc–bromine rechargeable batteries(ZBRBs)are one of the most powerful candidates for next-generation energy storage due to their potentially lower material cost,deep discharge capability,non-flammable electrolytes,relatively long lifetime and good reversibility.However,many opportunities remain to improve the efficiency and stability of these batteries for long-life operation.Here,we discuss the device configurations,working mechanisms and performance evaluation of ZBRBs.Both non-flow(static)and flow-type cells are highlighted in detail in this review.The fundamental electrochemical aspects,including the key challenges and promising solutions,are discussed,with particular attention paid to zinc and bromine half-cells,as their performance plays a critical role in determining the electrochemical performance of the battery system.The following sections examine the key performance metrics of ZBRBs and assessment methods using various ex situ and in situ/operando techniques.The review concludes with insights into future developments and prospects for high-performance ZBRBs.

Determination of Chlorine and Bromine in Plant Materials by Ion Chromatography

A method was developed for determination of chlorine and bromine in plant materials by ion chromatography using temperature programing-semi molten for sample preparation. Values of detection limits of the method found were 1.0×10^-5 for CI and 1.3×10^-6 for Br. The measuring range of the method found were 0.3-20.0 mg/L for CI and 4,0-120,0 μg/L for Br. The results obtained agreed quite well with those reference values.

Distribution of bromine and iodine in thermal power plant

The bromine （Br） and iodine （I） in raw coal, bottom ash （BA） and fly ash （FA） from seven thermal power plants （TPP） digested with pyrohydrolysis were determined by using inductively coupled plasma mass spectrometry （ICP-MS）. The distribution behavior of Br and I during coal combustion were researched and the environmental effects of Br and I in BA, FA and gas phase were analyzed. The results show that both elements Br and I in combustion products from TPP are usually pre- sent in decreasing order of the distribution rate as gas phase, FA and BA. In FA and BA, the distribution rate of Br （8.11% and 1.68%, respectively） are generally lower than that of I （9.26% and 4.67%, respectively）; on the contrary, in gas phase, the former （90.2%） is higher than the latter （86.9%）. In addition, for gas phase, the percentage of Br： （2.0%-75%） in total Br is generally larger than that of I2 （1.0%-10%） in total I. The environmental effects for Br and I emitted into atmosphere from TPP may be larger than those remained and captured by both FA and BA.

Non-aqueous lithium bromine battery of high energy density with carbon coated membrane

Flow batteries with high energy density and long cycle life have been pursued to advance the progress of energy storage and grid application. Non-aqueous batteries with wide voltage windows represent a promising technology without the limitation of water electrolysis, but they suffer from low electrolyte concentration and unsatisfactory battery performance. Here, a non-aqueous lithium bromine rechargeable battery is proposed, which is based on Br;/Br;and Li;/Li as active redox pairs, with fast redox kinetics and good stability. The Li/Br battery combines the advantages of high output voltage（;.1 V）,electrolyte concentration（3.0 mol/L）, maximum power density（29.1 m W/cm;） and practical energy density（232.6 Wh/kg）. Additionally, the battery displays a columbic efficiency（CE） of 90.0%, a voltage efficiency（VE） of 88.0% and an energy efficiency（EE） of 80.0% at 1.0 m A/cm;after continuously running for more than 1000 cycles, which is by far the longest cycle life reported for non-aqueous flow batteries.

Bromine-Graphite Intercalation Enabled Two-Electron Transfer for a Bromine-Based Flow Battery

Br_(2)/Br^(−)is a promising redox couple in fl ow batteries because of its high potential,solubility,and low cost.However,the reaction between Br^(−)and Br_(2)only involves a single-electron transfer process,which limits its energy density.Herein,a novel two-electron transfer reaction based on Br^(−)/Br^(+) was studied and realized through Br^(+) intercalation into graphite to form a bromine-graphite intercalation compound(Br-GIC).Compared with the pristine Br^(−)/Br_(2)redox pair,the redox potential of Br intercalation/deintercalation in graphite is 0.5 V higher,which has the potential to substantially increase the energy density.Diff erent from Br_(2)/Br^(−)in the electrolyte,the diff usion rate of Br intercalation in graphite decreases with increasing charge state because of the decreasing intercalation sites in graphite,and the integrity of the graphite structure is important for the intercalation reaction.As a result,the battery can continuously run for more than 300 cycles with a Coulombic effi-ciency exceeding 97%and an energy effi ciency of approximately 80%at 30 mA/cm^(2),and the energy density increases by 65%compared with Br^(−)/Br_(2).Combined with double-electron transfer and a highly reversible electrochemical process,the Br intercalation redox couple demonstrates very promising prospects for stationary energy storage.

Reversible Release and Fixation of Bromine in Vacancy-Ordered Bromide Perovskites

Bromine is an irreplaceable reagent for many important applications including necessary additive for flame retardants and rubber treatment.However,the toxicity,causticity,and vaporability of bromine make the safe usage and transportation of bromine challenging,which can be alleviated by the bromine prefixation.Herein,vacancy-ordered bromide perovskites such as Cs^(4)Sb_(2)Br_(12)and Cs_(2)PdBr_(6)are selected out for the bromine fixation through density-functional theory calculations and experiments.The redox within the bromide perovskites is designed to provide the driving force for the reversible release and fixation of bromine.Heating and cooling the title bromide perovskites in a necked ampoule make the bromine visible and separable from the solid residue.The composition engineering(i.e.,Cs_(4)Sb_(2)Br_(12)vs Rb_(4)Sb_(2)Br_(12),and Cs_(4)Sb_(2)Br_(12)vs Cs_(2)PdBr_(6))can effectively tune the stability(against water and high temperature)and the bromine storage capacity(from9.30%to 18.76%).In addition,this work can provide a one-step preparation method for the liquid bromine without further purification.

Automatic Detection Instrument for the Ratio of Chlorine to Bromine in Oxidized Liquid of Bromine Production Based on Fuzzy Method

In the process of bromine production,because of lag adjustment methods,there are problems of adjusting delay,raw material wastage and low growth rate.By considering the nature of bromine production,with the help of fuzzy data processing method,computer detection and display technique,we designed an automatic detection instrument for the ratio of chlorine to bromine in oxidized liquid of bromine production.This instrument can be used to detect the different parameters of raw materials adjustment and control in real time,and afford assurance that raw materials will be adjusted in time.This paper briefly introduces the working mechanism,hardware and software design of the instrument.

Anomalies of bromine in the estuarine sediments as a signal of floods associated with typhoons

X-ray fluorescence scanning with synchrotron radiation was performed to study sediment core records of floods in Amur Bay,Sea of Japan.Interlayers of 3–8 mm with abnormally low bromine content were formed by the Razdolnaya River discharge to the central part of the bay during extreme floods,accompanied by severe storms at sea.Such conditions in the region are typical for periods of deep tropical cyclones(typhoons),to which the distinguished interlayers were compared on the timescale.This approach was made possible thanks to the high rate of sedimentation in the bay(3–5 mm/a) and low bioturbation of sediments under anoxic conditions.

Oxidative Cyclization of Azo-coupling Products of 3-Isopropenyltropoloneand 3-Cinnamoyltropolone with Bromine

new method to synthesize heterocycle-fused troponoid compounds by oxidizing azocoupling products of 3-isopropenyltropolone and 3-cinnamoyltropolone with bromine in the presence of pyridine was reported for the first time. Reaction of azo-couping products of 3-isopropenyl tropolone 1a similar to f and 3-cinnamoyltropolone 3a similar to d with excess bromine afforded heterocycle-fused troponoid compounds 2a similar to f, 4a similar to d, respectively.

Reexploration of Structural Changes in Element Bromine through Pressure-Induced Decomposition of Solid HBr

Simple molecular solids have been an important subject in condensed matter physics,particularly for research of pressure-induced molecular dissociation.We re-explore the structural changes of element bromine through pressure-induced decomposition of solid HBr.The phase changes in HBr are investigated by Raman spectroscopy and synchrotron x-ray diffraction up to 125 GPa at room temperature.By applying pressure,HBr decomposes into solid bromine in the pressure range of 18.7-38 GPa.The solid bromine changes from molecular phase to incommensurate phase at 81 GPa,and finally to monatomic phase at 91 GPa.During the process of pressureinduced molecular dissociation, the intermediate incommensurate phase of element bromine is confirmed for the first time from the x-ray diffraction studies.The decomposition of HBr is irreversible since HBr cannot form again upon pressure decompression.

The Measurements of Highly Stripped Bromine Atom Spectra

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Computer simulation of the cluster destruction of stratospheric ozone by bromine

The interaction of （Br-）i（H2O）50-i, 0 ≤ i ≤ 6 clusters with oxygen and ozone molecules is investigated by the method of molecular dynamics simulation. The ozone molecules as well as the bromine ions do not leave the cluster during the calculation of 25 ps. The ability of the cluster containing molecular oxygen to absorb the infrared （IR） radiation is reduced in the frequency range of 0≤ w ≤ 3500 cm-1 when the number of the bromine ions in the cluster grows. The intensity of the Raman spectrum is not changed significantly when the Brions are added to the ozone- containing system. The power of the emitted IR radiation is increased when the number of bromine ions grows in the oxygen-containing system. The data obtained in this study on the IR and the Raman spectra of the water clusters that contain ozone, oxygen, and Br- can be used to develop an investigation of the mechanisms of ozone depletion.

Chlorination of water containing bromide and formation of the bromine－substituted trihalomethanes

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Importance of Bromine-Substituted DBP’s in Drinking Water

Significant fractions of bromine-substituted disinfection byproducts (DBPs)—particularly trihalomethanes (THMs)— have been observed to form during treatment of water from the Missouri River. THM speciation was also noted to follow a seasonal pattern during a 2.5-year period, during which samples were collected multiple times per month. Although some treatment processes were effective at reducing the chloroform formation potential, no treatment used at this utility significantly reduced the formation of the three bromine-substituted THM species. Using chloramination rather than free chlorination for secondary disinfection, however, was effective at limiting increases in the concentration of all four regulated THM species in the distribution system.

Analysis of Causes Leading to High Bromine Number of C_8^+ Aromatics and Short Clay Service Life and Countermeasures Proposed

After comparing the operating status of other catalytic reforming units and evaluation of the side-cut stream tests, the refinery investigated the influence of the feedstock property, clay types, and operating regime of the clay tower and catalytic reforming unit on the service life of the clay. Test results had revealed that the low potential aromatic content of the reformer feed and high operating severity were the critical causes leading to high bromine number of the C8^＋ aromatics feed for the PX unit and the shortened service life of clay. This article also puts forward the corresponding remedial measures.

XPS STUDIES ON SURFACE MODIFIED POLY [1-(TRIMETHYLSILYL)-1-PROPYNE] MEMBRANES Ⅱ SURFACE MODIFICATION BY BROMINE VAPOR

Surface modification of poly [1-(trimethylsilyl)-1-propyne] (PTMSP) membranes bybromine vapor has been studied. It is shown that Br/C atomic ratio at the surfaces increased withthe time of bromination until about 60 min, then it reached a plateau. The results of XPS and IRstudies indicated that the addition of bromine to double bonds and the replacement of H on CH_3 bybromine had taken place so that a new peak at 286.0 eV (C--Br)in C_(1s) spectra and some newbands, e. g. at 1220 and 580cm^(-1) in IR spectra were formed. The fact,t Po_2, permeability ofoxygen, decreased and α_(O_2/N_2), separation factor of oxygen relative to nitrogen, increased withbromination time, shows that surface modification of PTMSP by bromine may be an efficient approach to prepare PTMSP membranes used for practical gas separations.

Bromine-contained and Modified with Amino Group, D-π-A α-Cyanostilbenzene Derivative：Synthesis, Crystal Structure and Photoluminescence

A novel D-π-A type α-cyanostilbenzene derivative,（Z）-2-（4-aminophenyl）-3-（4-bromophenyl）-acrylonitrile（ABAN）, was designed and synthesized, by introducing an electrondonating amino group and a heavy atom. The structure of ABAN was confirmed by FT-IR, 1H NMR, 13 C NMR spectra and single-crystal X-ray diffraction analysis. The ABAN is of orthorhombic system, space group P212121, with a = 8.6100（14）, b = 9.6923（16）, c = 15.705（3） , Mr = 299.17, V = 1310.6（4） 3, Z = 4, Dc = 1.516 g/cm-3, μ = 3.119 mm-1, F（000） = 600, Rint = 0.038, R（I 〉 2σ（I）） = 0.0276, w R（I 〉 2σ（I）） = 0.0628, R（all data） = 0.0324, wR（all data） = 0.0646, completeness to theta = 25.00 was 99.8% and GOOF = 1.04. In the crystal structure, ABAN molecules were linked with each other through intermolecular C–H···π interactions and N–H···N hydrogen bonds, by which the 1D chain, 2D plane and 3D stacking structures were constructed. The photophysical properties and calculation results confirmed that ABAN possessed an intramolecular charge transfer（ICT） process. ABAN could be applied into the optoelectronic material field due to good solvent-tuned photophysical properties and highly thermal stability.

Determination of the Bromine, Manganese and Antimony in Nicotiana tabacum Solanaceae by Using the Neutron Activation Analysis Technique

Tobacco addiction has been mentioned as a leading cause of preventable illnesses and premature disability. Smoking is the main cause of lung cancer and one of the factors that most contribute to the occurrence of heart diseases, among others. The herbaceous species Nicotiana tabacum is a plant of the solanaceae family used for tobacco production. Some authors have conducted research about heavy metals and the toxicity of tobacco. It is, frequently, found in low concentrations in the ground, and superficial and underground waters, even though they do not have environmental anthropogenic contributions. However, with the increase of industrial activities and mining together with the agrochemical use of contaminated organic and inorganic fertilizers, an alteration of the geochemical cycle occurs. As a consequence, the natural flow of these materials increases and is released into the biosphere, where they are often accumulated in the superior layer of the ground, accessible to the roots of the plants. During planting and plant development, fertilizers and insecticides, including organochlorines and organophosphates, are used;consequently, the smoke from cigarette smoking presents various toxic substances, such as bromine (Br), manganese (Mn) and antimony (Sb), elements studied in this work. The procedures for the preparation of the samples were carried out in our laboratories and submitted to irradiation with thermal neutrons at Nuclear and Energy Research Institute (IPEN/CNEN-SP), in the Atomic Energy Institute IEA-R1 research reactor. The irradiated material was, then, analyzed by gamma spectrometry, using a high purity germanium detector (HPGe).

Preparation of pitch precursor with excellent spinnability for general-purpose carbon fibre using coal tar pitch as raw material

Tetrahydrofuran(THF) extract of coal tar pitch(CTP) was used instead of blending CTP with pretreated pyrolysis fuel oil to prepare an isotropic pitch precursor with excellent spinnability for general-purpose carbon fibre through bromination-dehydrobromination. The feasibility and effectiveness of synthesising an isotropic pitch precursor derived from THF-soluble(CTP-THFs) is demonstrated in this study.The results show that CTP-THFs contains more light components than CTP;CTP-THFs and CTP monomer proportions were 62.52% and 45.32%, respectively. However, based on comparisons of CTP-THFsBr0 and CTPBr0 characterisations, CTP-THFs exhibits better polycondensation than CTP. Bromination-dehydrobro mination promotes polycondensation of pitch precursors, leading to greater carbon aromaticity in CTP-THFsBr5, CTP-THFsBr10, and CTP-THFsBr15 than that in CTP-THFsBr0 and CTPBr0. CTP-THFsBr5 and CTP-THFsBr10 have excellent spinnability even with softening points as high as 230 ℃. The pericondensed carbon and carbon aromaticity of CTP-THFsBr5 and CTP-THFsBr10 are high owing to the higher degree of polycondensation;however, they still possess a more linear molecular structure. The as-prepared carbon fibre exhibits homogeneity and uniformity, and the mechanical performance is comparable with that of commercial general-purpose carbon fibre products.