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Introduction: Postpartum hemorrhage (PPH) is mostly caused by uterine atony and is the leading cause of maternal death. Hysterectomy may be necessary in severe cases, but uterine compressive sutures are an uterine-sparing alternative. In 2005, Alcides Pereira proposed a technique with serial superficial stiches around the uterus. To date, there were no further reports on its clinical use.Objective: To evaluate a tertiary center's experience with Alcides-Pereira's compressive uterine sutures for severe PPH due to uterine atony, reviewing its efficacy, morbidity, and impact on reproductive outcomes.Study Design: An 11-year retrospective cohort study of Alcides-Pereira's sutures for PPH at a single tertiary hospital. Demographic and obstetric data were collected. Details of subsequent pregnancies and fertility plans were collected through a telephonic interview. Comparison between women in which the sutures were effective and ineffective to prevent hysterectomy was made.Results: Alcides-Pereira's sutures were applied in 23 patients with PPH due to uterine atony. The technique was successful in controlling the hemorrhage and avoiding hysterectomy in 20 patients (87%). When successful, the sutures avoided the need for any blood therapy in 55% (RR 0.45, 95% CI 0.28-0.73) of patients, intensive care unit admission in 80% (RR 0.2, 95% CI 0.08-0.48) and significantly shortened the length of hospital stay. All patients with preserved uterus resumed their usual menstrual pattern. One had a subsequent term vaginal delivery; one had three first trimester miscarriages. All other patients did not try to conceive.Conclusion: Alcides-Pereira's sutures are a feasible, uterine-sparing technique, providing an effective and safe option for PPH. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pyrolysis oil contains inorganic chlorine and organochlorine compounds. • ZSM-5 catalysts can remove most Cl from organochlorine compounds at 180 °C. • KOH solution can eliminate half of Cl from inorganic chlorine compounds below 40 °C. • The alkaline solution-based neutralization process is reusable and regenerative. • The two processes can be synergized to enhance the dechlorination efficiency. Pyrolysis oil produced from municipal plastic waste can be utilized as fuel and various valuable chemicals as an alternative to petroleum. However, pyrolysis oil usually contains a relatively high concentration of chlorinated compounds, obstructing its utilization in the chemical industry. The present research reveals that pyrolysis oil contains inorganic chlorine and organochlorine compounds, and differentiated approaches should be considered to remove Cl from covalent and ionic chlorine linkages. Transition metal-based ZSM-5 catalysts showed remarkable dechlorination performance via mild C-Cl cracking of 1-chlorooctane and 4-chlorotoluene at 180 °C or below. The neutralization method of mixing pyrolysis oil with an alkaline solution quickly eliminated ionic chlorine from inorganic chlorine compounds, reducing Cl concentrations by up to 70 % at temperature below 40 °C. Based on the different dechlorinating pathways, an ideal combination of these two methods was suggested to enhance chlorine removal efficiency from pyrolysis oil. [ABSTRACT FROM AUTHOR]

[Display omitted] • The influence of the air relative humidity on the CdTe activation process has never been addressed. • The air humidity contained in the activation atmosphere could have beneficial or detrimental effects, depending on its level and the activation chlorine compound (i.e., CHClF 2 and CdCl 2). • The activation homogeneity on the sample area is compromised by the excess of humidity during the activation process. The humidity threshold for CdCl 2 was found. • Precise control of the air relative humidity in the activation process may be the key to achieving high solar-cell efficiencies. Chlorine treatment is considered one of the most important processes to obtain high-efficiency CdTe solar cells. Such treatments are usually performed by exposing the devices to CdCl 2 or other chlorine compounds and annealing them at high temperatures. Annealing processes were carried out in vacuum, inert atmosphere, reactive atmosphere, or air. The usage of ambient air has several advantages either technical or economical. However, the presence of moisture in the atmosphere may affect the treatment results or their reproducibility, especially in countries where the relative humidity (RH%) of the air could be an issue. However, despite many reports on CdTe Cl-treatments, the RH% effect on the finished solar-cell performance was not extensively reported. In this work, RH% was varied from 0% to 60%, comparing two different Cl treatments: CHClF 2 (gas) and CdCl 2 (in MeOH solution). It was observed that the RH% negatively affects the electrical properties of CHClF 2 -treated solar cells, while it could reduce the spatial uniformity using CdCl 2. We conclude that relative air humidity is a parameter that should be controlled for producing high-quality CdTe-based PV devices. [ABSTRACT FROM AUTHOR]

• N -chlorotaurine has bactericidal activity in the presence of lung epithelial cells. • N -chlorotaurine has fungicidal activity in the presence of lung epithelial cells. • The microbicidal activity is even enhanced in the presence of these cells. • The concentration of 1% N -chlorotaurine, which can be inhaled, shows good activity. N -chlorotaurine (NCT) is an endogenous active chlorine compound that can be used as an antiseptic and anti-infective in different body regions. Recently, tolerability of inhaled NCT has been demonstrated in humans so that it is of interest for future treatment of cystic fibrosis. In the present study, we tested the bactericidal and fungicidal activity of NCT in different lung cell culture models. Bacteria (Staphylococcus aureus, Pseudomonas aeruginosa) and fungi (Candida albicans, Exophiala dermatitidis) were co-incubated with lung epithelial cell cultures, and after 4 h NCT was added. After different incubation times, aliquots were removed and quantitative cultures were performed. NCT at the therapeutically applied concentration of 1% (55 mM) completely killed the test pathogens within 15 - 30 min at 20 °C and at 37 °C. Killing by 0.3% NCT lasted up to 4 h dependent on the pathogen at 20 °C and up to 1 h at 37 °C. 0.1% NCT was the threshold concentration for killing since this amount of oxidation capacity was consumed by reactions with the organic compounds of the medium within 3 h (20 °C) and 0.5 h (37 °C). NCT in therapeutic concentration demonstrated its microbicidal activity in the presence of lung epithelial cells. Remarkably, particularly the fungicidal activity was higher under these conditions than in phosphate buffer. This can be explained by formation of the stronger microbicidal monochloramine in equilibrium by transchlorination. The results suggest the suitability of NCT as inhalation medication in the lung. [ABSTRACT FROM AUTHOR]

Abstract An alternative method for the determination of total chlorine content in hydroxypropyl cellulose (HPC) was applied, combining a recently developed system based on a combustion step followed by pyrohydrolysis reaction. Using this approach it the determination of total chlorine by inductively coupled plasma optical emission spectrometry (ICP-OES) without interferences was feasible. It overcame the limitations of European Pharmacopoeia (EP) method for HPC analysis regarding to the inability to determine total chlorine in HPC, once some chlorine compounds (e.g., chloroform) that can not be identified by the official method (EP). The following parameters of combustion and pyrohydrolysis were evaluated: absorbing solution, sample mass, the use of powdered silica as retardant of combustion, oxygen flow rate and reaction time. Reference values for total chlorine were obtained after digestion using microwave-induced combustion and determination by ion chromatography (IC). Microwave-assisted extraction (MAE) was also investigated for Cl extraction. The accuracy of the proposed method was also evaluated by analyte recovery tests (agreement of 95–103%), as well as by the analysis of certified reference materials (CRMs). The agreement with the certified values was higher than 95% and the limit of quantification (LOQ) was 50 µg g−1. Up to 500 mg of sample were efficiently digested by the proposed method in 5 min (dissolved carbon in digests was below 50 mg L−1). Total chlorine content in samples of modified cellulose ranged from 284 to 576 µg g−1. Despite the relatively high chlorine content in all samples, the concentration was lower than the maximum limit allowed by the EP for HPC (0.5%). Graphical abstract fx1 Highlights • The proposed sample preparation method overcomes the limitation of the official method proposed by official pharmacopoeias. • Chlorine determination was possible in HPC excipient by ICP-OES. • Up to 500 mg of HPC were efficiently digested in 5 min. • The LOQ was 50 µg g−1, allowing the determination of chlorine in pharmaceutical excipients. • Higher digestion efficiency was achieved (>99%). [ABSTRACT FROM AUTHOR]

Abstract In this paper, the narrow size and spherical shape of boron carbide nanoparticles are synthesized by milling, purification and then the classification of nanoparticles by sedimentation method. In addition, the fractal behavior of particles is studied during synthesizing systematically and a fractal equation is proposed for prediction of nanopowders size distribution plots. Milling of particles is conducted in a stirred attrition mill for different times, and hydrochloric acid is used for solvent purification and then sedimentation process is conducted. The size of particles is measured by laser particle size (LPS) analyzer. For studying particles morphology, scanning and transmission electron microscopy (SEM, TEM) are used. The crystal size of nanoparticles is calculated by X-ray diffraction (XRD). LPS results reveal that after 110 h milling time, nanoparticles with an average diameter of 90 nm are produced. SEM images show that the final nanoparticles have equiaxed shape with iron impurity less than 1.7 wt. % after acid washing. XRD results demonstrate that the crystalline size of boron carbide (B 4 C) particles after 110 h of milling reduces from 220 to 57 nm. The fractal analysis shows that particles size distribution curves of finer particles can be predicted by proposed fractal modeling better in contrast to larger particles. Graphical abstract Image 108 Highlights • Two types of boron carbide (B 4 C) nanoparticles were synthesized by nanomilling. • Comminution started fast and reached to stable condition at the end of milling. • Nanoparticles had high purity, narrow size distribution and spherical shape. • TEM images revealed that the nanoparticles size was 50 nm in last stage. • Fractal equation predicted particles size of B 4 C nanoparticles with high accuracy. [ABSTRACT FROM AUTHOR]

Abstract Increasing generation of renewable electricity offers a source of green electric power, which can be exploited for the sustainable production of hydrogen through the electrolysis of water. Scarcity of fresh water resources promotes the search for electrode materials, which could be used for splitting of saline water into hydrogen and oxygen without formation of hazardous chlorine compounds, and also withstand highly aggressive chloride medium. In the present study we demonstrate that nickel oxide layer formed by means of simple spray-pyrolysis technique on conductive glass substrate can be used as corrosion resistant and 100% O 2 -selective anode for the electrolysis of alkaline (pH 14) chloride solution. Dimensional stability and durability of the anode is secured by the absence of metallic phase, whereas selectivity towards oxygen evolution and absence of chloride oxidation is shown to be controlled thermodynamically. The obtained experimental evidence that hydrogen peroxide is formed as intermediate in oxygen evolution reaction under conditions investigated has led to new mechanistic insights and the mechanism of Ni(IV)-mediated electrocatalytic oxidation of water molecules in alkaline chloride medium has been proposed. Graphical abstract Image 1 Highlights • Formation of durable FTO/NiO anode for saline water electrolysis is reported. • 100% selectivity of anode for OER in alkaline chloride solution is demonstrated. • Formation of hydrogen peroxide as intermediate in OER is evidenced. • Mechanism of Ni(IV)-mediated electrocatalytic OER is proposed. [ABSTRACT FROM AUTHOR]

Abstract The breakdown of Cu–cyanide complexes (decomplexation) and recovery of the associated copper was explored using a photoelectrocatalytic treatment incorporating Cl− in the electrolyte (PEC-Cl) and with WO 3 as a photoanode. Using the PEC-Cl process, the efficiency of decomplexation improved in the presence of a high concentration of Cl−. However, when the concentration of Cl− exceeded 20 mM, the deposited Cu could be oxidized to copper compounds by free chlorine (Cl 2 , HOCl, Cl and OCl), resulting in a decline in Cu recovery. The total nitrogen removal increased from 7.9% (PEC without Cl−) to 95.6% for the PEC-Cl process, which can be attributed to the generation of chlorine radicals (OCl and/or Cl). A mechanism for Cu–cyanide decomplexation and Cu recovery during the PEC-Cl process is proposed. Cu–cyanide complexes are destroyed by free chlorine, generating CNO− and Cu2+. The Cu2+ is then reduced onto the cathode and the CNO− is further oxidized into NH 4 + and HCOO−. NH 4 + is attacked by chlorine radicals and finally converted into N 2 while HCOO− is gradually degraded to CO 2 and H 2 O. Graphical abstract Unlabelled Image Highlights • Free chlorine generated on the photoanode enhanced the breakdown of Cu–cyanide complexes. • Chlorine radicals were beneficial to total nitrogen removal. • When the concentration of added Cl− was high, the deposited Cu could be oxidized by free chlorine. • A mechanism of Cu–cyanide decomplexation and Cu recovery in the presence of Cl− was proposed. [ABSTRACT FROM AUTHOR]

Abstract In this paper, 4 mol% ZnO-doped Zr 0.92 Y 0.08 O 2-α (8YSZ) and its 8YSZ+4ZnO/NaCl-KCl composite electrolyte were synthesized by a solid-state reaction. The X–ray diffraction (XRD) analysis indicates that 8YSZ+4ZnO and inorganic chlorides phases can coexist. The inorganic chlorides decrease the synthesis temperature of 8YSZ+4ZnO. The highest conductivities of 8YSZ+4ZnO and 8YSZ+4ZnO-NK are 7.0 × 10−3 S cm−1 and 7.7 × 10−2 S cm−1 at 700 °C, respectively. The oxygen concentration discharge cell shows that 8YSZ+4ZnO and 8YSZ+4ZnO-NK are good oxide ionic conductors under an oxygen-containing atmosphere. Finally, an H 2 /O 2 fuel cell based on the 8YSZ+4ZnO-NK electrolyte reached the maximum power density (P max) of 315.5 mW cm−2 at 700 °C. [ABSTRACT FROM AUTHOR]

The reduction rate of residual chlorine concentration in water distribution systems depends on water quality and system parameters. Temperature is the one of the important factors affecting the rate of chlorine decay, and flow velocity further affects chlorine variation along the distribution pipeline. In this study, we explored the combined impact of temperature and flow velocity on chlorine decay rate in water distribution systems. A pilot-scale water distribution system was designed and fabricated to obtain time series of residual chlorine concentration under various temperature and flow velocity conditions. The parameters of kinetic reaction models were calibrated using genetic algorithm for further generalization of kinetic coefficient prediction. The impact of flow velocity was incorporated into the Reynolds number and integrated into a combined equation to show the relationship of temperature to decay coefficients. The decay rate obtained from the combined equation shows good agreement between simulation and experimental verification. [ABSTRACT FROM AUTHOR]

Abstract Viscosity, pH and electrolytic conductivity of dilute, semidilute and concentrated chitosan solution with hydrochloric acid adding were compared and the change in conformation of chitosan in concentrated solution was discussed. The dissolution behavior of chitosan in concentrated chitosan hydrochloric acid solution was investigated through determination of solution turbidity, microstate and size of chitosan particle. It was found that the concentration, degree of deacetylation (DD) of chitosan and content of hydrochloric acid in solution showed significant effects on the changes in viscosity, pH, and electrolytic conductivity of chitosan solution as hydrochloric acid added. And the transforms of above properties of chitosan solution during dissolution were corresponding to the proportion of hydrochloric acid to chitosan from which we could deduced that the confirmation of chitosan changed from entangling with each other to becoming compact coils due to electrostatic screen of Cl− and hydrophobic aggregation of chitosan with high concentration. In concentrated suspension solution, chitosan particles agglomerated first and then expended before disintegrating and dissolving with hydrochloric acid adding, resulting in solution turbidity, size and microstate of chitosan particle changed obviously during dissolution. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Organic polypyrrole nanospheres were incorporated into the polyamide layer for new TFC membrane. • The incorporated organic nanospheres had favourable compatibility with the polyamide layer. • The prepared membranes exhibited improved permeability and salt rejection. • Excellent chlorine resistance and biocidal activity were achieved. Abstract To enhance the antibacterial property and chlorine resistance, organic nanospheres, polypyrrole (PPy), were innovatively incorporated into the polyamide (PA) layer for fabricating thin film nanocomposite (TFN) membranes. Owing to the improved hydrophilicity and compatibility between the PPy nanospheres and the PA layer, the obtained TFN membranes exhibited significant water flux enhancement without sacrificing salt rejection. Under the optimal PPy dosage (0.006 wt%), TFN membranes showed a high water flux of 42.19 L/(m2 h), which was 118.0% higher than that of the pristine membrane. Remarkably, the chlorine resistance of TFN membranes was strengthened after the incorporation of PPy nanospheres, as evidenced by the less decreased salt rejection, as compared with the TFC and commercial RO membrane. In addition, the positively charged PPy nanospheres immobilized in the PA layer endow the TFN membranes with improved biocidal activity, which was much higher than that of the pristine membrane. This study shows that incorporating organic nanospheres into the PA layer is an effective strategy to develop new TFN membranes with enhanced performance for advanced water purification. [ABSTRACT FROM AUTHOR]

Abstract 2-amino-4-methylbenzothiazole (AMBT) and one of its derivatives (E)-2-methylbenzo[d]thiazol-2-yl)imino-4-methyl) phenol (MBTP) were used as synergistic pair for the protection of mild steel in 0.5 M HCl. The combination of inhibitors, AMBT-MBTP, adsorbs on electrode surface through chemical and physical means. The antagonistic interaction was more pronounced on higher temperature, and an inhibition efficiency of 92% was recorded at 313 K and 93% at 303 K. The formation of protective film of AMBT-MBTP combination is further evidenced by SEM and AFM images. The process of adsorption followed Langmuir isotherm model and corresponding thermodynamic activation parameters were also calculated and discussed. Corrosion inhibition efficiency and the reaction kinetics of synergistic pair were evaluated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and weight loss measurements. H-bonding interaction and resulting enthalpy change and reactivity descriptors were computed for correlating the corrosion inhibition efficiency and molecular structure by B3LYP/6-31G∗ level of Density Functional Theory (DFT). [ABSTRACT FROM AUTHOR]

Abstract The solubility of CO 2 in seawater is known to increase at colder temperatures, but few studies have examined the CO 2 solubility in seawater and in sea-ice brines at sub-zero (Celsius) temperatures. The thermodynamic Henry's Law constant (K H) for CO 2 in concentrated NaCl solutions was determined for the first time at sub-zero temperatures and salinities resembling those of the cryospheric seawater and sea-ice brine environments in polar and sub-polar oceans. The temperature (T, in Kelvin) dependence of the K H within the temperature and salinity ranges of this study (263 ≤ T ≤ 272 K and 35 ≤ S ≤ 152) is described by the following best-fit equation: ln K H = −2.484 + 2.775 × 10−2(274 − T) − 9.854 × 10−2/(274 − T) − 1.009 × 10−1 ln (274–T). The results show that the general practice, in geochemical and coupled climate‑carbon cycling models, of extrapolating K H values from above-zero to sub-zero temperatures underestimates the solubility of CO 2 by up to 19%. Highlights • Henry's Law constant for CO 2 was determined in NaCl solutions at temperatures from −1 to −10 °C. • CO 2 solubility in cold seawater and sea ice-brines is higher than previously estimated. • Air-sea exchange of CO 2 and climate modeling need to revisit the solubility of CO 2 at sub-zero temperatures. [ABSTRACT FROM AUTHOR]

Graphical abstract Condensation reaction of two different chlorosilanes with the tetrasilanol of double-decker shaped silsesquioxane was performed. The reaction resulted in a mixture of three products including an asymmetric structure that can be isolated with liquid chromatography. Ratio of these three products depends of the type of chlorosilane used. Abstract A synthetic path to asymmetric side-capped double-decker shaped silsesquioxanes (DDSQ) and subsequent isolation is described. By strategically using a combination of dichloro and trichlorosilane capping agents, a resultant product with mixed silanol functionalities was obtained. The use of preparatory liquid chromatography (LC) cleanly separated DDSQ compound with asymmetric functionality, and HPLC provided a quantitative technique to analyze mixture ratios. These mixture ratios did not follow the expected statistical trend due to the steric effects on the rate of capping. As a consequence, a decreased amount of the desired asymmetric DDSQ was observed in some cases. This was overcome by varying the ratio of capping agents. Overall, this work demonstrates access to asymmetric DDSQ cages is feasible, and LC is an effective separation technique. [ABSTRACT FROM AUTHOR]

A novel water-soluble fluorescent probe based on the removal of HON moiety was presented, which could monitor ClO − with rapid response and excellent selectivity. In physiological pH condition, a good linear balance between the fluorescence intensity and the ClO − concentration was found with high sensitivity (8.3 nM). Additionally, this probe could be immobilized on test strips, which exhibited visible changes under UV light illumination. Its outstanding performance made the successful application in water samples and RAW264.7 cells. [ABSTRACT FROM AUTHOR]

New disinfection procedures are being developed and proposed for use in drinking-water production. Authorising their use requires an effective test strategy that can simulate conditions in practice. For this purpose, we developed a test rig working in a flow-through mode similar to the disinfection procedures in waterworks, but under tightly defined conditions, including very short contact times. To quantify the influence of DOC, temperature and pH on the efficacy of two standard disinfectants, chlorine and chlorine dioxide, simulated use tests were systematically performed. This test rig enabled quantitative comparison of the reduction of four test organisms, two viruses and two bacteria, in response to disinfection. Chlorine was substantially more effective against Enterococcus faecium than chlorine dioxide whereas the latter was more effective against the bacteriophage MS2, especially at pH values of >7.5 at which chlorine efficacies already decline. Contrary to expectation, bacteria were not generally reduced more quickly than viruses. Overall, the results confirm a high efficacy of chlorine and chlorine dioxide, validating them as standard disinfectants for assessing the efficacy of new disinfectants. Furthermore, these data demonstrate that the test rig is an appropriate tool for testing new disinfectants as well as disinfection procedures. [ABSTRACT FROM AUTHOR]

Abstract With the aim of studying the process of blackening of lead white in mural painting, a set of samples from the Cimabue’s paintings at the Assisi Cathedral have been studied by Raman and XRD methods, complemented with related techniques (i.e. reflection FTIR, XRF, SEM-EDS). The investigation highlighted that a complete oxidation of lead white to lead dioxide occurred all over the external paint layer having a thickness of 20–30 microns. This alteration occurred both when lead white was applied alone and when used in mixture with azurite, that appears partially converted to copper chlorine compounds. Chemical mapping by Raman spectroscopy and SEM-EDS allowed a good characterization of the painting technique to be carried out. The secco painting nature shown by the examined samples excludes that the oxidation of lead white occurred as a consequence of the alkaline nature of the fresco mortar. Conversely, a possible role of chlorine compounds has been highlighted. [ABSTRACT FROM AUTHOR]

Abstract The efficiency of 4-(4-hydroxy-3-methoxy benzyledene amino)-4-H-1,2,4-triazole-3, 5-dimethanol, HMATD, as corrosion inhibitor for mild steel in 0.5 M HCl has been determined by weight loss measurements and electro analytical methods. The influence of various parameters such as temperature, inhibitor concentration on the efficiency has been studied. The electrochemical impedance spectroscopic measurements revealed the inhibition action of HMATD by reducing the charge transfer through metal solution interface. Polarization curves indicate the mixed type behaviour of HMATD. The inhibitor molecule functions by blocking the active sites on metal surface by adsorption and which obeys the Langmuir adsorption isotherm. Various kinetic and thermodynamic parameters have also been calculated. [ABSTRACT FROM AUTHOR]

Degradation of three lipid regulators, i.e., gemfibrozil, bezafibrate and clofibric acid, by a UV/chlorine treatment was systematically investigated. The chlorine oxide radical (ClO • ) played an important role in the degradation of gemfibrozil and bezafibrate with second-order rate constants of 4.2 (±0.3) × 10 8  M −1  s −1 and 3.6 (±0.1) × 10 7  M −1  s −1 , respectively, whereas UV photolysis and the hydroxyl radical (HO • ) mainly contributed to the degradation of clofibric acid. The first-order rate constants ( k ′) for the degradation of gemfibrozil and bezafibrate increased linearly with increasing chlorine dosage, primarily due to the linear increase in the ClO • concentration. The k ′ values for gemfibrozil, bezafibrate, and clofibric acid degradation decreased with increasing pH from 5.0 to 8.4; however, the contribution of the reactive chlorine species (RCS) increased. Degradation of gemfibrozil and bezafibrate was enhanced in the presence of Br − , whereas it was inhibited in the presence of natural organic matter (NOM). The presence of ammonia at a chlorine: ammonia molar ratio of 1:1 resulted in decreases in the k ′ values for gemfibrozil and bezafibrate of 69.7% and 7%, respectively, but led to an increase in that for clofibric acid of 61.8%. Degradation of gemfibrozil by ClO • was initiated by hydroxylation and chlorine substitution on the benzene ring. Then, subsequent hydroxylation, bond cleavage and chlorination reactions led to the formation of more stable products. Three chlorinated intermediates were identified during ClO • oxidation process. Formation of the chlorinated disinfection by-products chloral hydrate and 1,1,1-trichloropropanone was enhanced relative to that of other by-products. The acute toxicity of gemfibrozil to Vibrio fischeri increased significantly when subjected to direct UV photolysis, whereas it decreased when oxidized by ClO • . This study is the first to report the transformation pathway of a micropollutant by ClO • . [ABSTRACT FROM AUTHOR]

Photodynamic therapy is an alternative form of cancer treatment that meets the desire for a less aggressive approach to the body. It is based on the interaction between a photosensitizer, activating light, and molecular oxygen. This interaction results in a cascade of reactions that leads to localized cell death. Many studies have been conducted to discover an ideal photosensitizer, which aggregates all the desirable characteristics of a potent cell killer and generates minimal side effects. Using Density Functional Theory (DFT) implemented in the program Vienna Ab-initio Simulation Package , new chlorin derivatives with different functional groups were simulated to evaluate the different absorption wavelengths to permit resonant absorption with the incident laser. Gaussian 09 program was used to determine vibrational wave numbers and Natural Bond Orbitals. The chosen drug with the best characteristics for the photosensitizer was a modified model of the original chlorin, which was called as Thiol chlorin. According to our calculations it is stable and is 19.6% more efficient at optical absorption in 708 nm in comparison to the conventional chlorin e6. Vibrational modes, optical and electronic properties were predicted. In conclusion, this study is an attempt to improve the development of new photosensitizer drugs through computational methods that save time and contribute to decrease the numbers of animals for model application. [ABSTRACT FROM AUTHOR]

Zeolite-templated carbon (ZTC) was synthesized for the adsorption of imidazolium-based ionic liquids (ILs), including [C 4 mim][Cl], [C 8 mim][Cl] and [C 16 mim][Cl]. To clarify the adsorption mechanism, three carbonaceous materials coconut-shell-based activated carbon (CSAC), coal-based activated carbon (F300) and ordered mesoporous carbon material (CMK-3) were also prepared as additional sorbents. The sorbents were characterized by X-ray diffraction, transmission electron microscopy, N 2 adsorption, X-ray photoelectron spectroscopy, Raman spectroscopy and zeta potential measurements in terms of structural and surface characteristics. Batch adsorption tests indicated that the CSAC exhibited a high adsorption capacity for short-alkyl-chain [C 4 mim][Cl], originating from the micropore-filling effect. ZTC displayed a markedly higher adsorption capacity for long alkyl-chained [C 16 mim][Cl] compared with other tested sorbents due to its regular-shaped, open and interconnected channel structure, as well as the good matching between pore size and adsorbate dimension. The uniform pore structure also endowed ZTC and CMK-3 with considerably faster adsorption kinetics for [C 16 mim][Cl] than the activated carbons. Thermodynamic studies revealed that the uptake of [C 16 mim][Cl] on ZTC was spontaneous physical adsorption. [C 16 mim][Cl] adsorption was enhanced by increasing the ionic strength of the aqueous solution and was slightly influenced by the solution pH. Additionally, ZTC was easily regenerated with ethyl alcohol for reuse for at least ten times. Thus, the findings demonstrated that ZTC is an ideal candidate for the adsorptive removal of long-alkyl-chain ILs from water and wastewater. [ABSTRACT FROM AUTHOR]

Two new Schiff bases, N -(4-methoxybenzylidene)-2-[2-(( E )-2-(4-methoxybenzylideneamino)phenyl)disulfanyl]benzenamine ( Sb1 )) and N -(4nitrobenzylidene)-2-[2-(( E )-2-(4-nitrobenzylideneamino)phenyl)disulfanyl]benzenamine ( Sb2 )), were investigated as corrosion inhibitors for mild steel in 1 M HCl solution using weight loss measurements, potentiodynamic polarization and electrochemical impedance spectroscopy measurements. The results revealed that the Schiff bases act as effective corrosion inhibitors and the inhibition efficiency was increased by increasing inhibitors concentration. The adsorption of these compounds obeyed the Langmuir adsorption isotherm. The Sb1 molecule possessing an electron-donating O -methyl substitute showed a better inhibition performance in comparison with the Sb2 with nitro substitute, because of the positive effect of its electron–donating substitute. The molecular dynamics simulation, in agreement with experimental outcomes and quantum chemical data, showed higher inhibition efficiency for Sb1 . It also showed that the Sb2 molecules oriented not beneficially on metal surface which provided a low surface coverage, and thus, a lower inhibition performance. [ABSTRACT FROM AUTHOR]

The bioactive 19- nor -clerodane trans -dehydrocrotonin ( t -DCTN) is herein used as starting material to afford an epimeric derivative mixture so called t -DCTN-α and β-OL, which is a diastereoisomeric pair. The stereoselective reduction of t -DCTN was performed in methanol medium by using NaBH 4 and CeCl 3 ·7H 2 O which react reducing the C2 carbonyl group on the t -DCTN decalin ring moiety. The t -DCTN-diastereoisomeric compounds were characterized by chromatographic HPLC analyses and by NMR data. The crystal structure of t -DCTN-α-OL was confirmed employing X-ray diffraction. Additionally, an experimental and theoretical NMR chemical shifts study applied to the t -DCTN diastereoisomeric derivatives lead favorable coefficients of correlation (R > 0.98) by using B3LYP combined with 6–311++G(d,p) basis set. Furthermore, a modified Gemal and Luche's mechanism in stepwise fashion is proposed. Agreement between theoretical and experimental higher reactivity of NaBH 4 /Ce 3+ towards NaBH 4 was found and the theoretical results explicit the participation of the reaction solvent (methanol) on transition state by using NaBH 4 unlike that involving NaBH 4 /Ce 3+ . It was found that the proposed modified mechanism only occurs in 0.8 eq. of Ce 3+ salt. [ABSTRACT FROM AUTHOR]

The degradation of iopamidol and diatrizoate sodium (DTZ) by UV/chlorine was carried out according to efficiency, mechanism, and oxidation products, and compared to that by UV/H 2 O 2 . The pseudo-first order rate (k′) of iopamidol and DTZ was accelerated by UV/chlorine compared to that by UV and chlorine alone. k′ of iopamidol and DTZ by UV/chlorine increased with increasing chlorine dosage. Both of iopamidol and DTZ could not be effectively removed by UV/H 2 O 2 compared to that by UV/chlorine. Secondary radicals (Cl 2 − and ClO ) rather than primary radicals (HO and Cl ) were demonstrated to be mainly responsible for the enhanced removal of iopamidol and DTZ by UV/chlorine. The oxidation products of iopamidol and DTZ resulting from UV/chlorine and UV/H 2 O 2 process were identified, and differences existed in the two systems. IO 3 − (the desired sink of I − ) was the major inorganic product in the UV/chlorine process whereas I − was the predominant inorganic product in the UV/H 2 O 2 process. The formation of chlorine-containing products during the degradation of iopamidol and DTZ by UV/chlorine was also observed. H-abstraction, additions, de-iodination were shared during the degradation of iopamidol by UV/chlorine and UV/H 2 O 2 . Neutral pH condition was preferred for the removal of iopamidol and DTZ by UV/chlorine. UV/chlorine could also be applied in real waters for the removal of iopamidol and DTZ. [ABSTRACT FROM AUTHOR]

Surface functionality of nanodiamonds is of crucial importance for their desired chemical, optical and electromagnetic properties. Chlorinated surfaces are expected to enable an easy further modification of diamond surfaces via various substitution reactions for targeted molecule grafting, particularly interesting for biochemical applications. Previously reported chlorination approaches of diamonds required troublesome handling of hazardous chemicals, such as chlorine gas, and long chlorination time or high temperature. Here, we describe a radiation chemistry approach using electron beam irradiation for efficient surface chlorination of nanodiamonds (with averaged diameter of ca. 30 nm) at ambient temperature. Nanodiamonds with hydrogenated and graphitized surfaces were used for chlorination in CCl 4 , CHCl 3 and CH 2 Cl 2 at increasing radiation doses. A comprehensive set of measurements, including XPS, ATR-FTIR and in-source thermal desorption mass spectrometry (IS-TD-MS) was applied to characterize the chlorinated products. Density functional theory (DFT) calculations were performed to assist the discussion of reaction mechanisms. It is confirmed that remarkable covalently chlorine-covered surfaces bearing adequate stability against air and water were achieved for hydrogenated nanodiamonds in CCl 4 by applying doses ≥500 kGy. [ABSTRACT FROM AUTHOR]

The effectiveness of 30 to 400 ppm chlorine dioxide (CDO), acidified sodium chlorite (ASC) and peroxyacetic acid (PAA) to control Escherichia coli O157:H7 in beef was examined. Ground beef made from treated meat was vacuum packaged and stored at 4 °C for 4 d. CDO or ASC concentration by storage time interaction for inactivation of E. coli O157:H7 was significant ( P < 0.05). Exposure of beef to 200 and 400 ppm CDO caused 0.73 and 1.25 log cfu/g reduction in the numbers of pathogen, respectively, and an additional 2.08 and 2.25 log cfu/g reduction, respectively, occurred at day 4. At 400 ppm ASC caused a 0.87 log cfu/g reduction and an additional 0.86 log cfu/g inactivation at day 4. PAA caused ≤ 0.8 log cfu/g reduction in pathogen numbers at ≤ 400 ppm. Among tested antimicrobials, CDO was most effective and had a positive interaction with cold storage where additional E. coli O157:H7 inactivation occurred. [ABSTRACT FROM AUTHOR]

2-Chloro/phenyl-7-arylimino-6,6-dimethylcyclopenta [b] pyridylnickel chlorides ( Ni1 – Ni8 ) were synthesized from the respective ligands L1 – L8 and characterized. Upon activation with either methylaluminoxane (MAO) or ethylaluminium sesquichloride (EASC), they show high catalytic activity of up to 10.84 × 10 6 g(oligomer) mol − 1 (Ni) h − 1 in ethylene oligomerization. The products range from butenes to dodecenes for Ni1 – Ni4 , but are limited to butenes and hexenes in the case of Ni5 – Ni8 . DFT calculations indicate that the Ni C bond length in the model alkyl complexes depends both on the nature of the substituents at the heterocycles and the kind of the alkyl group, shedding some light on the preferences of the precatalysts toward oligomers or polyethylene. [ABSTRACT FROM AUTHOR]

The leaching pretreatment has been adopted to mitigate the ash-related problems encountered during gasification and combustion of sodium-rich coals. However, the wide-spread applications of this technology are limited to produce the ultra clean coal through remove all the ash by some aggressive agents. In the present study, some mild agents, such as deionized water, ammonium acetate solution and diluted hydrochloric acid, were employed to selectively remove troublesome sodium rather than all the ash. The primary leaching conditions such as particle size, temperature, residence time and concentration of agents were optimized by orthogonal experiments for the first time to achieve maximum removal efficiency of sodium (RES). Based on the range analysis, it was found that the significant factor was leaching temperature in the water-leaching (W-leaching) treatment and the RES showed a positive correlation with temperature. However, in both ammonium acetate-leaching (A-leaching) and diluted hydrochloric acid-leaching (H-leaching) treatments, the concentration of agents were found to play the dominant role and RES presented a volcanic relationship with it. Under optimal conditions, the leaching treatments were less time-consuming with improved RES (47.6% for W-leaching, 97.9% for A-leaching and 96.8% for H-leaching). Besides, the properties of coal samples after leaching were determined by a series of analysis methods. The results showed that the leaching treatments could significantly decrease the content of AAEMs and coal ash. Due to the removal of AAEMs, the ash fusion temperatures increased, while both gasification and combustion reactivity decreased obviously. The application to other three sodium-rich coals confirmed that the optimal leaching conditions had a good universality. [ABSTRACT FROM AUTHOR]

In order to increase the photodynamic effect of Chlorin e6, four Chlorin e6-artesunate conjugates were designed and synthesized. Among them, three conjugates ( 3 , 6 , 9 ) contained single artesunate side chain at 15 2 , 17 3 and 13 1 of Chlorin e6, respectively, and one conjugate ( 11 ) contained three artesunate side chains. In the in vitro evaluation of photodynamic effect, the four conjugates showed more potent phototoxicity against HepG2 cells than Chlorin e6. The introduction of artesunate side chain significantly increased the intracellular ROS production, although the production of singlet oxygen was not improved. Compound 11 exhibited much more potent phototoxicity than the other conjugates because the three artesunate side chains greatly enhanced the ROS production and cellular uptake. The results demonstrated that the conjugation of Chlorin e6 and artesunate could accomplish synergistic effects of chemo-phototherapy, and finally enhanced their antiproliferative effects. [ABSTRACT FROM AUTHOR]

In this research, a novel IMAC sorbent with high specificity for chlorine-containing compounds was developed. Ni-functionalized monodisperse spherical mesoporous silica particles of 500 ± 25 nm diameter were synthesized and their metal affinity properties were studied with the use of diclofenac as the model substance. The particles were aggregatively stable in the pH range of 3–12. The sorbent demonstrated a high adsorption capacity (0.60 ± 0.06 μg of DCF per 1 mg of the sorbent) and high adsorption/desorption rate (20 and 5 min was enough for the sorbent saturation and desorption of DCF, correspondingly). A mixture of eluents with addition of PFOS providing the almost complete recovery (98%) of diclofenac was first proposed. The monodispersity and the high sedimentation and aggregative stability of the particles provide the formation of a stable hydrosol even under ultrasound treatment which makes the mSiO 2 /Ni particles suitable for batch chromatography. [ABSTRACT FROM AUTHOR]

The room temperature reactions between R 3 SiH (R 3 = Et 3 , PhMe 2 , Ph 2 Me) and R′ 3 SiCl (R′ 3 = Me 3 , PhMe 2 , Ph 2 Me), with an excess of dimethylformamide (DMF) in the presence of (Me 3 N)Mo(CO) 5 as a catalyst, result in the initial formation of R 3 SiCl, R′ 3 SiOSiR′ 3 and Me 3 N as detected by 29 Si, 13 C, 1 H NMR spectroscopy and GC/MS. As the reaction proceeds, the more so if the reaction temperature is raised, mixed disiloxanes R 3 SiOSiR′ 3 and ultimately lesser amounts of R 3 SiOSiR 3 may be detected. A mechanism involving the activation of chlorosilanes by the nucleophilic DMF is proposed to produce transient imminium siloxy ion pairs, [Me 2 N CHCl] + [R′ 3 SiO] − ⇌ [Me 2 N CH(OSiR′ 3 )] + Cl − which react with R 3 SiH to form Me 2 NCH 2 OSiR′ 3 and R 3 SiCl. A secondary reaction of Me 2 NCH 2 OSiR′ 3 with R′ 3 SiCl produces the symmetrical disiloxane R′ 3 SiOSiR′ 3 and ClCH 2 NMe 2 . The final stage of the reaction is the reduction of ClCH 2 NMe 2 by R 3 SiH, a reaction which is reported for the first time. The newly created chlorosilane R 3 SiCl can become involved in the initial DMF activation chemistry thereby forming the other disiloxanes observed as the reaction proceeds. [ABSTRACT FROM AUTHOR]

Environmental effect evaluation of disinfection of combined sewer overflow events with alternative chemical disinfectants requires that the environmental toxicity of the disinfectants and the main by-products of their use are known. Many disinfectants degrade quickly in water which should be included in the evaluation of both their toxicity as determined in standardized tests and their possible negative effect in the water environment. Here we evaluated according to the standardized ISO 8692 test the toxicity towards the green microalgae, Pseudokirchneriella subcapitata, of three disinfectants: performic acid (PFA), peracetic acid (PAA) and chlorine dioxide (ClO2) as well as two by-products of their use: hydrogen peroxide (H2O2) and chlorite. All of the five chemicals investigated showed clear toxicity to the algae with well-defined dose response curves. The EC50 values ranged from 0.16 to 2.9mg/L based on nominal concentrations leading to the labeling of the chemicals as either toxic or very toxic. The five investigated chemicals decreased in toxicity in the order chlorine dioxide, performic acid, peracetic acid, chlorite and hydrogen peroxide. The stability of the chemicals increased in the same order as the toxicity decrease. This indicates that even though ClO2 has the highest environmental hazard potential, it may still be suitable as an alternative disinfectant due to its rapid degradation in water. [ABSTRACT FROM AUTHOR]

The PAH and OCP concentrations in sediment cores collected from a deep lake were measured and evaluated chronologically. The results indicated that the PAH and OCP concentrations significantly increased from the 1950s to the 1990s and subsequently decreased to recent years. Integrated molecular diagnostic ratios indicated that the predominant petrogenic sources occurred from the 1950s–1980s. Petroleum and fuel combustion dominated the source of contamination more recently as a result of energy structure changes in this region. Additionally, HCHs and DDTs were the dominant OCP compounds, making up a majority of the total OCPs present (>85%). HCHs accounted for a larger ratio of the OCPs between the 1950s and 1980s, suggesting that HCHs were the dominant POPs in this period. DDTs then became dominant in the 1980s and later. High α/γ-HCH ratios suggested that the emission and conversion of local technical HCHs were the predominant HCHs source. The ratios of (DDE + p,p’-DDD)/DDTs and p,p’-DDT/DDTs indicated that the DDTs mainly originated from historical input. In addition, the dramatic decrease since the 1980s may be the result of China’s banning of DDTs. However, DDTs were still present in the 1990s, suggesting DDTs were still used in this region and beyond. [ABSTRACT FROM AUTHOR]

This work presents a convenient method to fabricate large-area scrobiculate sub–10 nm Ag nanocavity arrays (NCA) through a facile replication and deposition process. Periodical cone-shaped NCA were constructed on the composite multi-layered noble metal film with cavity diameters abridged to the sub–10 nm scale. The resultant Ag NCA exhibited excellent SERS characteristic for Rhodamine 6G (R6G) and achieved a high enhancement factor of 3 × 10 9 . The enhancement was found to be quantitatively related to the concentration of the R6G probe solutions. The enhancement characteristic was testified via a Raman mapping across a 50 μm × 50 μm area on the substrate surface and achieved high homogeneity within the territory. For the SERS determination of Polychlorinated Biphenyls (PCBs), the surface of the NCA was modified with thiolated β-Cyclodextrin (HS-β-CD) and was thus functionalized as an incubation host for the PCBs molecules. Results suggest that the as-fabricated substrates show great potential in the SERS determination of the PCBs. [ABSTRACT FROM AUTHOR]

This paper focused on the effect of hydrochloric acid and nitric acid on phase transformation of gamma to alpha alumina. The microstructure, phase composition of specimens and crystallite sizes of α-Al 2 O 3 are investigated by X-ray diffraction, SEM, Scherrer formula and external standard method. The results showed that the phase transitions of alumina was affected by the kinds and concentrations of inorganic acid. Hydrochloric acid was more advantageous to promote the transformation of γ-alumina to α-alumina than nitric acid above 900 °C. In addition, the α-fraction of specimens obtained by Al 2 O 3 -HCl gels increased from 71.0% to 87.1% after calcination at 1000 °C when acid concentration increased from 0.1*10-4 mol/L to 0.1mol/L. On the contrary, the α-fraction of specimens obtained by Al 2 O 3 -HNO 3 gels decreased from 79.4% to 73.9%. And at 1100 °C up to nearly 100% of α-alumina in the specimens was obtained. Moreover, both hydrochloric acid and nitric acid were beneficial to the growth of the crystallite sizes of prepared α-Al 2 O 3 . Meanwhile the effect of hydrochloric acid on the phase transitions of alumina was further promoted by employing a two-step heat-treatment method. XRD and SEM confirmed that the first-step heat-treatment played an important role in the course of the calcination processes for low-temperature of α-alumina formation. [ABSTRACT FROM AUTHOR]

Formaldehyde is commonly used to overcome contaminants introduced by hatching eggs or water supply in the hatcher cabinets. However, health risks associated with its use make economical alternatives important. This project evaluated a chlorine dioxide based product (CDBP) (0.3% concentrate) as a hatchery sanitizer in decontaminating microbial populations on the shell surface of hatching eggs (>18 d old), as well as its impact on hatchability and chick performance. Hatchers (0.20 m²) designed to hold approximately 50 eggs and equipped with circulation fans, heaters, and thermostats were used for the evaluation. For each of the 2 trials conducted, 450 hatching eggs were obtained and incubated in a common setter. Eggs used in trial 1 were floor eggs whereas in trial 2 nest eggs were used. On d 18 of incubation, eggs were removed from the setter, and viable eggs were randomly allocated to 9 hatchers. Pre-treatment egg rinse samples (10 eggs per hatcher) were collected for initial microbial analysis. Three hatchers were treated with CDBP and 3 hatchers with a formaldehyde based product (FBP). Three untreated hatchers served as control (C). Prior to hatch, 10 eggs/incubator, not previously rinsed, were used for post treatment microbial counts. The hatched chicks were reared until d 21 in floor pens with a common starter diet. For the CDBP treated eggs, hatchability and chick performance (weight gains, mortality, and FCR on d 7 and d 21) were similar to the other treatments. The application rate of CDBP evaluated in this study was not an effective antimicrobial alternative to formaldehyde for sanitizing hatching eggs in hatcher cabinets prior to hatch. [ABSTRACT FROM AUTHOR]

Antipyrine (ANT, phenazone), a widely used anti-inflammatory analgesic in medical treatment, has been frequently detected in the aquatic environment. Chlorine disinfection process is thought as an efficient way to remove ANT, however, the potential risks of chlorine disinfection by-products (DBPs) such as trihalomethane (THMs) and haloacetic acids (HAAs) cannot be ignored. Chlorine dioxide (ClO 2 ) has been adopted as an effective alternative disinfectant of chlorine to reduce THMs and HAAs formation. In this work, the reaction kinetics and degradation pathway of ANT with ClO 2 were studied to investigate the feasibility of using ClO 2 as oxidant to degrade ANT. Experimental results demonstrated that ANT oxidation by ClO 2 followed second-order kinetics, and the second-order rate constant ( k app ) was determined to be 4.8 × 10 −1 M −1 s −1 at neutral pH. Higher pH could accelerate the reaction when pH < 9, while strong alkaline environment (pH > 9) might significantly slow down the oxidation process. Structural change during the reaction was proposed with the assistance of Fourier transform infrared spectroscopy (FT-IR), C C and C N bond of ANT were vulnerable under electrophilic attack of ClO 2 . Degradation pathways of ANT with ClO 2 were suggested based on the main intermediate products. ANT was firstly transformed into ANT-Cl through single-electron-transfer (SET) and substitution reaction. Further oxidation of this intermediate product involved ring-opening reaction and de-carbonyl reaction. [ABSTRACT FROM AUTHOR]

p -Cholorosulfinylaniline was prepared by the reaction of p- chloroaniline and SOCl 2 . The structural, conformational and configurational properties of the obtained liquid compound were studied by Raman and infrared spectroscopy in the liquid state. The assignment of the vibrational spectra was carried out with the help of data obtained by quantum chemical calculations at the harmonic oscillator approximation and using anharmonic vibrational self-consistent field (VSCF) method as well. The 1 H and 13 C NMR chemical shifts of the molecule were calculated by Gauge including orbital (GIAO) method (DFT/B3LYP approximation using 6-311 + G (df), 6-311++G (df,pd) and cc-pVTZ basis sets) and compared to the experimental values. Natural Bond Orbital analysis provides an explanation of the stability of the molecule and its electronic properties upon charge delocalization. [ABSTRACT FROM AUTHOR]

Two hybrids 1,7-heptanediammonium di-halide, [(C 7 H 20 N 2 ]X 2 ,X = Cl/Br crystallize in monoclinic P 2 1 / c , Z = 4. [(C 7 H 20 N 2 ]Cl 2 : a = 4.7838 (2) Å, b = 16.9879 (8) Å, c = 13.9476 (8) Å, β = 97.773 (2)°, V = 1203.58(10) Å 3 , D = 1.137 g/cm 3 , λ = 0.71073 Å, R = 0.052 for 1055 reflections with I > 2σ(I), T = 298(2) K. [(C 7 H 20 N 2 ]Br 2 : a = 4.7952 (10) Å, b = 16.9740 (5) Å, c = 13.9281 (5) Å, β = 97.793 (2)°, V = 1203.83(6) Å 3 , D = 1.612 g/cm 3 , λ = 0.71073 Å, R = 0.03 for 1959 reflections with I > 2σ(I) T = 298(2) K. Asymmetric unit cell of [(C 7 H 20 N 2 ]X 2 ,X = Cl/Br, each consist of one heptane-1,7-diammonium cation and two halide anions. The organic hydrocarbon layers pack in a stacked herring-bone manner, hydrogen bonded to the halide ions. Lattice potential energy is 1568.59 kJ/mol and 1560.78 kJ/mol, and cation molar volumes are 0.295 nm 3 and 0.300 nm 3 for chloride and bromide respectively. DTA confirmed chain melting transitions for both hybrids below T ∼ 340 K. Dielectric and ac conductivity measurements (290 < T K < 410; 0.080 < f kHz<100) indicated higher conductivity and activation energy of bromide for T > 340 K. Cross over from Jonscher's universal dielectric response at low temperatures T < 340 K to super-linear power law for T > 340 K is observed. At high temperatures halide ion hopping in accordance with the jump relaxation model prevails. [ABSTRACT FROM AUTHOR]

Chlorite is a by-product that can be produced in the disinfection process of a drinking water treatment plant (DWTP) using chlorine dioxide. The aim of this work was to evaluate the influence of the adsorption process with activated carbon on chlorite removal and to demonstrate how laboratory-scale and pilot-scale tests can be useful to predict granular activated carbon (GAC) performance on chlorite removal at full scale in a DWTP. A first series of tests were carried out at laboratory scale using small carbon columns. A second series of tests were performed at semi-full scale using a pilot plant at the DWTP of Vescovana (Padova, Italy). The laboratory-scale tests show that carbon pre-loading significantly reduces the ClO2 - removal yield, by about 30%-40%. Both laboratory-scale tests and small column tests show that in virgin conditions the mineral carbon shows a higher ClO2 - removal efficiency than the vegetal one, while in pre-loaded conditions an opposite behavior is observed. The results of the pilot plant test show that GAC ensures a good ClO2 - removal yield, close to 55%. The results show that small column tests at laboratory scale are extremely useful to predict pilot column performance and, therefore, full-scale DWTP performance. [ABSTRACT FROM AUTHOR]

This work investigates the possibilities of high-resolution continuum source graphite furnace molecular absorption spectrometry for the direct determination of Cl in solid samples via the CaCl molecule and measurement of its molecular absorption. The method proposed is based on addition of 400 µg Ca as molecule-forming reagent and of 20 µg Pd as chemical modifier, which helps to stabilize the analyte and enhances sensitivity. The molecular spectrum for CaCl offers different lines with different limits of detection and linear ranges, which permitted to analyze solid samples with different Cl contents. The lowest limit of detection (0.75 ng Cl, corresponding to 0.75 µg g −1 for a typical sample mass of 1 mg) could be achieved by combination of three of the most sensitive lines in the vicinity of 620.862 nm, while the amplest linear range (up to 860 ng Cl) was achieved by selection of the less sensitive line at 377.501 nm. The method developed enabled the direct determination of Cl in solid samples using simple external calibration with aqueous standards. Good precision (5–9% RSD) and accuracy was attained in a series of certified samples of very different nature (i.e. coal, iron oxide, polyethylene, human hair, pine needles, rice flour and milk) and with very different Cl contents, ranging from about 50 µg g −1 to 1% (w/w) Cl. The method appears as particularly useful for Cl determination in samples with elevated Ca contents, for which biased results with other diatomic molecules, such as AlCl or SrCl, may be obtained. [ABSTRACT FROM AUTHOR]

The thermochemical and kinetic studies of dissolution of magnesium-carbonate co-substituted fluorapatites in 3 wt% hydrochloric acid solution were performed using microcalorimetry at a temperature between 25 and 55 °C. The results were processed iteratively in order to deduce the thermochemical and kinetic parameters. Increasing the temperature leads to an increase in the apparent rate constant and an increase in the enthalpy of dissolution (between −230 and −140 kJ mol −1 ). A kinetic scheme has been proposed with an order close to 2 with respect to the apatite. Simultaneous incorporation of CO 3 and Mg ions into the fluorapatite generates a decrease in the activation energy from 20 to 6 kJ mol −1 . These values suggest a diffusion controlled phenomenon. The isoconversional model showed that the dissolution occurs in a single step and led to activation energies values close to that of the kinetic model ones. [ABSTRACT FROM AUTHOR]

Disinfection of fresh fruit and vegetables after harvest is an essential first step of postharvest handling. The minimal requirement from disinfection procedures is to maintain commodities and facilities free of fungal postharvest pathogens and bacterial human pathogens and thus improve food safety. Disinfection of postharvest pathogens that accumulate on the fruit surface before and during harvest is a direct benefit and in particular cases it can by itself prevent decay after storage. The current review includes historical, chemical, and regulatory background on some of the major disinfectants available for usage today. These include chlorine, chlorine dioxide, ozone, ethanol, hydrogen peroxide, organic acids, and electrolyzed water. Some of the disinfectants described in this review are in wide usage for many years and some are considered ‘alternative’ and are at initial levels of usage. Information is given on experimental reports, practical application, phytotoxicity, residues, advantages, disadvantages and mode of action of the compounds and technologies. Special emphasis is given to vapor and gas phase applications due to their unexploited potential and to some complementary technologies that have been reported in recent years. The conclusion from the many details in this review is that disinfection is an important tool to ensure management of postharvest decay of fresh produce. In some cases, disinfection is a precondition to successful implementation of major postharvest technologies and in particular cases it can become the major technology. An important aspect arising from this review is also that some of the bad reputation of chemical disinfectants is unjustified because they leave no or non-toxic levels of residues and their environmental impact is minor in view of their potential benefits. [ABSTRACT FROM AUTHOR]

Graphene, a novel class of carbon nanostructures, has received great attention as sorbents due to its fascinating structures, ultrahigh specific surface area, and good extraction ability. In this paper, a new type of hierarchical graphene was synthesized through employing a mild and environment-friendly method. Such 3D interconnected graphene own a high specific surface area up to 524 m 2 g −1 , which is about 2.5 fold larger than the graphene, since the synthetic material has interlayer pores between nanosheets and in-plane pores. Then a superior solid-phase microextraction fiber was fabricated by sequentially coating the stainless steel fiber with silicone sealant film and hierarchical graphene powder. Since the novel hierarchical graphene possessed large surface area and good adsorption property, the as-prepared fiber exhibited good extraction properties of the organochlorine pesticides (OCPs). As for the analytical performance, the as-prepared fiber achieved low detection limits (0.08–0.80 ng L −1 ) and wide linearity (10–30,000 ng L −1 ) under the optimal conditions. The repeatability (n=5) for single fiber were between 5.1% and 11%, while the reproducibility (n=3) of fiber-to-fiber were range from 6.2% to14%. Moreover, the fiber was successfully applied to the analysis of OCPs in the Pearl River water. [ABSTRACT FROM AUTHOR]

A two-stage pretreatment process is proposed in this research in order to improve sugar recovery from corn stover. In the proposed process, corn stover is hydrolyzed by dilute hydrochloric acid to recover xylose, which is followed by a Fenton reagent oxidation to remove lignin. 0.7 wt% dilute hydrochloric acid is applied in the first stage pretreatment at 120 °C for 40 min, resulting in 81.0% xylose removal. Fenton reagent oxidation (1 g/L FeSO 4 ·7H 2 O and 30 g/L H 2 O 2 ) is performed at room temperature (about 20 °C) for 12 has a second stage which resulted in 32.9% lignin removal. The glucose yield in the subsequent enzymatic hydrolysis was 71.3% with a very low cellulase dosage (3 FPU/g). This two-stage pretreatment is effective due to the hydrolysis of hemicelluloses in the first stage and the removal of lignin in the second stage, resulting in a very high sugar recovery with a low enzyme loading. [ABSTRACT FROM AUTHOR]

Using the distribution of free chloride concentration ( C f ) and total chloride concentration ( C t ) measured by different grades and species of coral concrete (CPC) soaking in sea water, the chloride binding capacity ( R ), surface free chloride concentration ( C s ) and apparent chloride diffusion coefficients ( D a ) of CPC were calculated. Then, the influence of curing age and exposure time on the durability of chloride in coral concrete were discussed, and the superior of magnesium sulfate cement (MSC) in resisting chorine salt erosion were verified. The results indicated that the CPC R values increased whereas the C s values decreased with the extension of the curing age. The relationship between the exposure time and C s followed an exponential form; however, its growth rate was considerably lower than that of ordinary concrete (OPC) due to its high water absorbability. Furthermore, the decreasing relationship between D a and the exposure time conformed to the power function. The CPC D a exposed for 10–25 a under a laboratory-simulated marine environment was 88.9–99.1% lower than that in an actual marine environment. The D a of CPC was 0.5–6.6 times higher than that of any other type of concrete but decreased more quickly with the exposure time. After studying the CPC chloride diffusion parameters C f , C t , R , C s and D a , the advantages of MSC against the erosion due to chloride salt were fully demonstrated. Hence, for a CPC structure under an actual marine environment, extending the moisture curing age or using MSC will improve its ability to resist chloride diffusion, reduce the speed of chloride intrusion and prolong the service life of the structure. [ABSTRACT FROM AUTHOR]

Chloride ingress in concrete is the most deteriorating factor for reinforced concrete structures exposed to marine environment. This phenomenon depassivates reinforcing steel in concrete and causes steel corrosion. To improve the durability and serviceability of concrete structures in harsh environments with high relative humidity, temperature and concentration of chloride ions such as in the Persian Gulf, the addition of silica fume and other pozzolans have been recommended by several investigations. In this paper, the chloride ion diffusivity and mechanical performance of concretes containing silica fume, metakaolin and natural zeolite, and those of concretes with different water-cement ratios (w/c) under in-situ tidal exposure condition were investigated. To achieve this objective, concrete specimens with w/c of 0.35, 0.40, 0.45 and 0.50 were fabricated. In addition, to examine the performance of pozzolans, other specimens with constant water-binder ratio (w/b) of 0.40 containing 5% silica fume, 5% metakaolin and 10% natural zeolite were prepared. All of the specimens were subjected to laboratory and tidal exposure in the field conditions. The results indicate that 10% natural zeolite, 5% metakaolin and 5% silica fume have similar effects on concrete strength and durability in harsh marine environments. In addition, it is concluded that at long time field exposure, chloride diffusion coefficient and surface chloride content of different mixtures reach to relatively similar amounts. [ABSTRACT FROM AUTHOR]