Simultaneous Determination of Bisphenols and Alkylphenols in Water by Solid Phase Extraction and Ultra Performance Liquid Chromatography-tandem Mass Spectrometry

To establish an analytical method for determination of four bisphenols （BPA, BPB, BPF, and BPS） and two alkylphenols （4-n-OP, 4-n-NP） in water by ultra performance liquid chromatography- tandem mass spectrometry （UPLC/MS/MS）. The water samples were extracted and condensed with solid-phase extraction （SPE） using C18 cartridges and eluted by acetonitrile. Separation was carried out with Acquity BEH C8 column and detection were performed by UPLC/MS/MS. Quantification was calculated by using the internal standard BPA-d16 and 4-n-NP-d8. The linear correlation coefficients of these compounds in the range of 1.0-100.0μg/L were all over 0.999. The minimum detectable concentrations were 0.75-1.0 ng/L, and the recoveries ranged from 87.0% to 106.9%.

Experimental study on total dissolved gas supersaturation in water

More and more high dams have been constructed and operated in China. The total dissolved gas （TDG） supersaturation caused by dam discharge leads to gas bubble disease or even death of fish, Through a series of experiments, the conditions and requirements of supersaturated TDG generation were examined in this study. The results show that pressure （water depth）, aeration, and bubble dissolution time are required for supersaturated TDG generation, and the air-water contact area and turbulence intensity are the main factors that affect the generation rate of supersaturated TDG. The TDG supersaturation levels can be reduced by discharging water to shallow shoals downstream of the dam or using negative pressure pipelines. Furthermore, the TDG supersaturation levels in stilling basins have no direct relationship with those in reservoirs. These results are of great importance for further research on the prediction of supersaturated TDG generation caused by dam discharge and aquatic protection.

Pulsed high-current discharge in water:adiabatic model of expanding plasma channel and acoustic wave

This paper presents the results of a theoretical and experimental study of the use of a pulsed discharge in water to obtain a strong acoustic wave in a liquid medium.A discharge with a current amplitude of 10 kA,a duration of 400 ns,and an amplitude pulsed power of 280 MW in water at atmospheric pressure created an expanding acoustic wave with an amplitude of more than 100 MPa.To describe the formation of the discharge channel,an isothermal plasma model has been developed,which made it possible to calculate both the expansion dynamics of a high-current channel and the strong acoustic wave generated by it.Our calculations show that the number density of plasma in the channel reaches 10^(20) cm^(-3),while the degree of water vapor ionization is about 10%,and the channel wall extends with a velocity of 500 m s^(−1).The calculations for the acoustic wave are in good agreement with measurements.

Thermodynamic Evaluation of Mineral Balance in Water Thickness of the Soda Lake Doroninskoe(Eastern Transbaikalia,Russia)

In recent years,lakes,including salted,attract the attention of researchers,also when reconstructing last climate changes using the bottom sediments(Solotchina et al.,2008,et al.).In this case the different geochemical

THE FREE BENDING VIBRATION OF CYLINDRICAL TANK PARTIALLY FILLED WITH-LIQUID AND SUBMERGED IN WATER

This paper studies the free bending vibration of cylindrical tank partially filled with liquid and submerged in water. The depths of liquid and water may be completely arbitrary. The exact calculating formulae of mode shape functions and inherent frequencies are deduced. The results can be gained by means of computer. The analysis shows that the effect of liquid and water on vibration of cylindrical tank is respectively equivalent to a generalized distributive mass attached to the tank.

Monitoring and analysis of shock wave in water for underwater drilling blasting

Taking the underwater reef blasting in Gulei sea channel of Xiamen Port as an example,the forming characteristic of shock wave in water for underwater drilling blasting is analyzed.By field monitoring,the pressure of shock wave in water for different distances is attained;the major parameters such as pressure amplitude and positive action time,and the propagation attenuation rule of shock wave in water are analyzed in this paper.The results can be helpful for engineering design and construction and environmental safety assessment.

Oxa-Pictet-Spengler reaction in water.Synthesis of some(±)-1-aryl-6,7-dimethoxyisochromans

An acid catalyzed oxa-Pictet-Spengler reaction‘on water leading to the synthesis of a variety of l-aryl-6,7-dimethoxyisochro-mans is described.The aqueous chemistry is a much cleaner,efficient,cheaper and simple method for synthesis.The scope of reactions was extended to thia-Pictet-Spengler reaction to afford the some isothiochromans.

Characteristic Analysis of AC Plasma Arc in Water

An experimental system of AC arc discharge in water was designed with pole-pole electrodes and a peak voltage of 1500 V and a test circuit was set up using virtual instrument technology. The mechanism of an AC plasma arc generated in water was analyzed. The voltage- current characteristic of the AC plasma are was obtained from the waveform. The temperature characteristic was tested with a spectrum diagnosis system, and the effect of different electrode materials on the striking voltage and peak current was analyzed. The results show that when a power supply of 6 kW is applied on electrodes with a gap of 2 mm in water, the striking voltage is from 900 V to 1300 V, the arc voltage is from 40 V to 100 V, the arc current is from 2 A to 7 A, and the zero rest period is from 1 ms to 2 ms. In addition, the arc voltage and current are different for electrodes in aluminum, copper and stainless steel. The arc voltage is lower and the current is higher for an aluminum electrode than those for copper and stainless steel ones. The highest temperature of the arc is 7643 K.

Influence of Forward Speed on the Lateral Vibration of a Slender Structure in Water

In this paper,the effects of forward speed on the lateral vibration of a slender structure in an infinite fluid are considered.By equating the bending stress of the structure with the hydrodynamic force acting on it,the equation which governs the fluid-structure interaction of a slender structure both vibrating and moving in water is obtained.Numerical results show that the influence of forward speed on the vibration of a slender structure in water is significant.It behaves like damping,reducing both natural frequencies and responses significantly.

DETERMINATION OF ANTIMONY IN WATER SAMPLES BY FLOW-INJECTION HYDRIDE GENERATION ATOMIC ABSORPTION SPECTROMETRY WITH ON-LINE ION-EXCHANGE COLUMN PRECONCENTRATION

On-line ion-exchange separation and preconcentration were combined with flow-injection hydride generation atomic absorption spectrometry (HGAAS) to determine ultra-trace amounts of antimony in water samples. Antimony(Ⅲ) was preconcentrated on a micro-column packed with CPG-8Q chelating ion-exchanger using time-based sample loading and eluted by 4 mol l^(-1) HCl directly into the hydride generation AAS system. A detection limit (3σ) of 0.0015μg l^(-1) Sb(Ⅲ) was obtained on the basis of a 20 fold enrichment and with a sampling frequency of 60h^(-1). The precision was 1.0% r.s.d.(n=11) at the 0.5μg l^(-1) Sb(Ⅲ) level. Recoveries for the analysis of antimony in tap water, snow water and sea water samples were in the range 97-102%.

AN INVESTIGATION OF THE HYDROPHOBIC AGGLOMERATION CHARACTERISTICS OF EASY DEGRADATION COAL FINES IN WATER

The separation of ultrafine coal from three Chinese coal samples of easy degradation coal fines in water has been investigated by the application of a hydrophobic agglomeration process. In addition to yielding clean coal with high recovery, this process requires significantly less oil concentration for agglomeration (less than 0.4% in oil-water weight ratio) and produces stabler agglomerates than general oil agglomeration process, the cost of the oil would no longer be an important consideration for its commercial application. Neutral diesel oil was used to make oleophilic coal particles agglomerated with good rejection of clay minerals under little oil consumption and certain agitation speed at 2000 r/min. An important advantage of this process compared with other cleaning fine coal methods is that it can extremely reduce or eliminate the effects of coal degradation and some clay minerals on coal preparation.

Molecular Orbital Nature of Solubility of Shot Chain n-Alkanes in Water and Their Reaction Rate Constants with Nitronium Cations: A DFT Study

The new theoretical models describe both the solubility S of the shot chain n-alkanes in water at 298.15 K, and their reaction rate constants k with nitronium cation NO2+ at 293.15 K on the basis of their molecular orbital characteristics. It is shown that both the quantities S and k are determined by the energies Eorb of the specific virtual (for S) and occupied (for k) molecular orbitals of these n-alkanes. The obtained regression equations confirm the theoretically found dependences of S and k on the absolute value of Eorb. This fact demonstrates that the electronic structure particularities of the studied n-alkanes play a crucial role in both their above-mentioned physicochemical properties.

Determination of Chromate Ion in Water Using High Performance Capillary Electrophoresis

A new rapid method for the analysis of chromate ion in water by using high performance capillary electrophoresis is described. The detection limit is 1.0 mu g/ml by using 100 m mol/l Tris-HCl buffer containing 2 m mol/l 1,6-hexanediamine which was used as an electroosmosis modifier to improve the separation and detection sensitivity.

Mechanism of Electromagnetic Flow Control Enhanced by Electro-Discharge in Water

Pulsed discharge utilized to achieve large current density in the electromagnetic flow control is numerically studied. A mathematic discharge model is established to calculate the plasma channel, and an actuator is designed to generate the Lorentz force in the micro plasma channel. During the discharge process, the resistance in the channel decreases rapidly and a large current density appears between the discharge electrodes. After the actuator is applied in the leading edge of a flat plate, the separation region and downstream turbulent boundary layer on the plate disappear. Meanwhile, a skin-friction drag force reduction is achieved.

SPECTROFLUORIMETRIC DETERMINATION OF GERMANIUM WITH MORIN IN WATER AND HEALTH DRINK

A highly sensitive and fairly selective spectrofluorimetric method has been developed for the determination of germanium with morin in tap water and health drink. The fluorescent reaction and optimal conditions of germanium with morin in phosphoric acid medium were studied. The detection limits of germanium in tap water and health drink were found to be 0.2 and 0.7μd/L respectively.

Determination of Radon Content in Water Respecting to Directive of Council 2013/51/EURATOM

In accordance with the recommendations of the most recent Directive of Council EURATOM No. 2013/51, which concerns requirements for the protection of the health of the general public with regard to radioactive substances in water intended for human consumption, we are obligated to monitor the level of approximate dose of radioactive substances. The directive indicates two basic isotopes: tritium and radon, which ought to be monitored continuously. Essential are also para-metric values as well as frequency, methods of monitoring of radioactive substances and equipment requirements. Directive states that measurements of content of tritium and radon ought to be taken as well as calculations of approximate dose natural and artificial radionuclides content should be done, apart from tritium, potassium-40, radon and short-living products of radon disintegration. In case if one of radioactive concentrations is over 20% of computational value or concentration of tritium is over parametric value analysis of additional radionuclides is required. A detailed list of radionuclides is presented in appendix No. 3 in the Directive. Laboratory of Nuclear Control Systems and Methods in the Institute of Nuclear Chemistry and Technology (INCT) worked out a Miniature Liquid Scintillation Counter (LCS) [1] [2], within a project titled “New generation of intelligent radiometric devices with cordless transmission of information” (UDA-POIG.01.03.01-14-065/08) co-financed by European Union from the European Regional Development Fund (ERDF). This Miniature Liquid Scintillation Counter may be used as a basic equipment resulting in the above mentioned directive. This article presents results of conducted research based on LCS and comparison of this results with the measurements carried out by Accredited Laboratory for Cali-bration of Dosimetric and Radon Instruments in Central Laboratory for Radiological Protection in Warsaw (CLOR).

Effects of Different Heavy Crude Oil Fractions on the Stability of Oil-in-water Emulsions —— Isolation of functional fractions from heavy crude oil and study of their properties

The functional fractions (acid, basic, amphoteric and neutral fractions) are isolated from the Liaohe Du-84 heavy crude oil and Shengli Gudao Kenxi heavy crude oil by ion-exchange chromatography, but the conventional fractions (saturates, aromatics, resins and asphaltenes) are also isolated from the heavy crude oil. These components have been characterized by spectroscopic methods (FT-IR), namely acid number, basic nitrogen number, ultimate analysis and molecular weight measurements using vapor pressure osmometry (VPO). The ion-exchange chromatography method based on separation by a functional group induces a little change on the nature of the crudes and reasonable mass balances can be easily obtained.