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[Display omitted] Although solar steam generation is promising for seawater desalination, it is less effective in purifying wastewater with both salt/heavy metal ions and organic contaminants. It is thus imperative to develop multifunctional integrated solar-driven water purification systems with high solar-thermal evaporation and photocatalytic degradation efficiencies. Herein, a lamellar reduced graphene oxide (L-RGO) foam with the vertical lamellar structure is fabricated by bidirectional-freezing, lyophilization, and slight chemical reduction for water purification. The unique vertical lamellar structure not only accelerates upward transport of water for facilitating water evaporation but also endows the L-RGO foam with superb high elasticity for tuning the interlayer distance and varying interactions between the oxygen-containing groups and water molecules to adjust water energy state. As a result, the L-RGO foam achieves a superb water evaporation rate of 2.40 kg m−2 h−1 along with an energy efficiency of 95.3 % under the compressive strain of 44.7 % under 1-sun irradiation. Equally importantly, the decoration of L-RGO foam with polypyrrole is capable of efficiently degrading organic pollutants while retaining high solar steam generation performances, exhibiting great potential in the comprehensive treatment of various water sources for relieving freshwater crisis. [ABSTRACT FROM AUTHOR]

Many studies have shown that the brain can process subliminal numerals, i.e., participants can categorize a subliminal number into two categories: greater than 5 or less than 5. In the context of many studies on the unconscious integration of multiple subliminal stimuli, the issue of whether multiple subliminal numbers can be integrated is contentious. The same-different task is regarded as a perfect tool to explore unconscious integration. In the two experiments reported, we used a same-different task in which a pair of masked prime numbers was followed by a pair of target numbers, and participants were asked to decide whether the two target numbers were on the same (both smaller or larger than 5) or different sides (one smaller, the other larger than 5) of 5 in magnitude. The results indicated that the prime numbers could be categorized unconsciously, which was reflected by the category priming effect, and that the unconscious category relationship of the two prime numbers could affect the judgment on the category relationship of the two target numbers, as reflected by the response priming effect. The duration of the prime-to-target interstimulus interval (ISI) was also manipulated, showing a positive compatibility effect (PCE) of category priming and a negative compatibility effect (NCE) of response priming no matter whether the ISI was short (50 ms) or long (150 ms). The NCE, which occurred when the prime-to-target ISI was relatively short in this study, contradicted the conventional view but was consistent with previous results of unconscious integration based on an attention modulation mechanism. Importantly, this study provided evidence for the still-under-debate issue of numerical information integration. [ABSTRACT FROM AUTHOR]

Three new approximately uniform color spaces named MLUV, MLUV1, and MLUV2 were developed by modifying CIELUV lightness, u′v′ chromaticity coordinates, and u*v* color coordinates, respectively. Performance tests using the combined and four individual datasets employed at CIEDE2000 development showed that MLUV, MLUV1 and MLUV2 were significantly better than CIELUV. Using values of Standardized Residual Sum of Squares (CIE 217:2016) for predictions of the four individual datasets the ranking (from best to worst) was MLUV, MLUV2 and MLUV1, but for predictions of two ellipses datasets the ranking (from best to worst) was MLUV2, MLUV, and MLUV1. Overall, the MLUV2 space was found to be the best. Hence, it is expected that MLUV2 could be used for color specification and color difference evaluations, especially in industrial applications that depend on additive light mixing, such as color TV sets, video monitors, and lighting. [ABSTRACT FROM AUTHOR]

A methodology using the subset simulation and the modified Metropolis-Hastings algorithm with delayed rejection (SS-MMHDR) is developed to evaluate the time-dependent reliability of corroded pipelines under multiple failure modes. This methodology considers the competition between the small leak and burst failures and the correlated non-normal distribution of the defect variables, and characterizes the defect geometric probability distribution from extensive inspection data. Results demonstrate that SS-MMHDR has high accuracy and low variability in evaluating the pipeline failures, outperforming the SS-MMH and Monte Carlo simulation algorithms, especially under low probability levels, but with slightly increased computation time. The Generalized Extreme Value Type II (GEVII) distribution is the optimal distribution for internal corrosion defect lengths from the Kolmogorov-Smirnov test. Lognormal, Weibull and Normal distributions provide more conservative estimates on burst and composite failure probabilities and limiting maintenance times than GEVII. Effects of operating pressure and its variability, corrosion rate on failure probability, and pipeline limiting maintenance time are also revealed through numerical cases. [ABSTRACT FROM AUTHOR]

A hyperspectral camera (HSC-type Specim IQ) has been applied at the linear plasma device PSI-2 under steady-state conditions. The camera has the capacity of hyperspectral imaging (HSI) with the dimension of a data array 512 × 512 × 204 (x, y, λ) covering the spectral span from 400 to 1000 nm with moderate average spectral resolution (FWHM ∼7 nm). After radiometric calibration and background/continuum emission subtraction, two main applications of the camera, (i) plasma diagnostics in helium (He) plasmas and (ii) plasma–material interaction studies with tungsten (W) targets in neon (Ne) plasmas, have been carried out. The measurements were complemented by a movable Langmuir double probe system (LP) measuring electron temperature (Te) and electron density (ne) in radial direction r and a fiber-coupled cross-dispersion spectrometer with high spectral resolution (Spectrelle) recording neutral He, W, and Ne emission lines over the full plasma column. (i) Two-dimensional (2D) imaging of Te and ne radial profiles in axial direction z of the He plasma column were for the first time obtained by the regression analysis of Te and ne (from LP) and six He I line ratios (from HSC). The spatially resolved plasma parameters covered in these studies range between Te ∼ 0.8–13.4 eV and ne ∼ 0.2 × 1018–3.9 × 1018 m−3 and permit a reconstruction of the plasma conditions in PSI-2 in 2D without LP perturbation. (ii) W sputtering was studied in situ in Ne plasmas exposing W target samples (negatively biased at 100 V) under perpendicular Ne plasma impact. Simultaneously, the 2D distributions of W (W I line at 429.5 nm) in front of the target and the 2D Ne plasma distribution (Ne I line at 703.2 nm) were recorded with complete spectral separation as confirmed by the Spectrelle spectrometer. This permits the simultaneous measurement of the neutral W penetration and its angular distribution induced in the sputtering process and of the impinging plasma distribution. The HSI technique offers, despite a few technical drawbacks, such as the moderate spectral resolution and poor time resolution, a new possibility to distinguish multiple emission lines from plasma and impurities and complements the portfolio of existing Optical Emission Spectroscopy techniques, providing a good compromise regarding spectral, spatial, and temporal resolution. [ABSTRACT FROM AUTHOR]

Turbulent drag can be reduced by the use of anti-turbulent additives, which are often associated with significant economic benefits. For half a century turbulent drag reduction has become a hot research topic. However, under the strong hydrodynamic force of turbulent flow, chains of the polymer's macromolecules may undergo significant mechanical degradation. In the present work, we investigated drag reduction and mechanical degradation characteristics of oil-soluble polymer-polyalphaolefin (PAO) in turbulent flows in a parallel-plate disk rheometer, cylindric rotational rheometer, and commercial oil pipeline. The influence of Reynolds number, temperature, polyalphaolefin composition, and concentration on polymer mechanical degradation have been analyzed. We revealed different degradation behaviors in turbulent flows for oil-soluble polymers in rheometer and pipeline. A degradation law for oil-soluble polymers in a rheometer and a general model of degradation in the pipeline have been derived, which can be used to predict drag reduction efficiency DR and effective polymer concentration θ in rheometer and commercial pipelines. The models are in high agreement with experimental results. [Display omitted] • Degradation behaviors of polyalphaolefin in turbulent flow have been evaluated in disk rheometer and commercial pipeline. • Polymer degradation time is much longer than the stretching developing time. • Polymer chain's scission behavior in disk rheometer and pipelines has been proposed. • In jet flow increasing DR is due to the combined effects of polymer dissolution and stretching. • A general exponential model of polymer degradation in pipelines is conducted. [ABSTRACT FROM AUTHOR]

It is common to have a wax layer on the inner wall of waxy crude oil pipeline. However, the study of the wax layer on the heat transfer of buried pipeline systems is inadequate due to its instability of composition and properties; it may lead to the inaccurate prediction of the pipeline temperature field. Based on the finite element simulation technology, a three-dimensional heat transfer model of buried crude oil pipeline involving wax layer was proposed and solved. The thermal effect of the wax layer on pipeline system was analyzed quantitatively. Numerical results show that the average deviation of soil temperature near the pipeline reach 1.42 K when there is a 4 mm wax layer. Among different thermal conductivity models of heterogeneous materials, the EMT model plays best in predicting the conductivity of a waxy layer. By setting different working conditions, the influence mechanisms of several thermal influencing factors are discussed. The results show that the thermal influence range of heated pipe is positively associated with oil temperature and velocity. The core thermal response zone is about 12 m along the X-axis. Beyond 8 m depth from ground surface, the temperature fluctuation of soil is almost unaffected by the oil pipeline. [ABSTRACT FROM AUTHOR]

In the process of tritium storage, the high-pressure storage vessel may be damaged due to accidental conditions, such as impact or drop, which results in tritium leakage. The tritium gas will be released and diffused into the space immediately, which inevitably causes radioactive hazards to personnel and the environment. Ventilation is considered to be the best emergency treatment method for a tritium leakage accident. According to the characteristics of fixed tritium amount and rapid release of tritium in the tritium leakage accident of the high-pressure storage vessel, the numerical simulation of high-pressure released tritium behavior in a confined space is carried out based on Fluent and compared with CATS test data. The error is no more than 5%. The ventilation conditions are optimized according to different ventilation positions and different ventilation rates. It is founded that the tritium removal efficiency when the vent is set on the roof is 30% higher than that on the side wall. The tritium concentration in a confined space can be reduced to the background level after ventilation for 30 min at a rate of 0.5 m3 s−1. The optimal recovery time of the environment is given, which provides technical support for the emergency treatment of the tritium leakage accident of the high-pressure storage vessel. [ABSTRACT FROM AUTHOR]

In the gas-gathering pipeline networks in gas fields, launching pigs in the downstream pipeline causes dramatic fluctuations in the gas transportation volume and pressure in upstream pipelines. It is important to shorten the launching period of pigs for the safe and smooth production of pipeline networks. In this study, a hydraulically activated power launching (HAPL) method was proposed based on the hydraulically activated power pigging (HAPP) method. Based on the proposed HAPL method, the launcher structure was designed. Then, a nonlinear dynamics model for launching pigs was established and relevant parameters were simulated. The simulation results showed that the launching period with the HAPL method was 76.5% shorter than that of the pneumatically activated power launching (PAPL) method under the same conditions. [ABSTRACT FROM AUTHOR]

In order to solve the problem of demulsification difficulties in Liaohe Oilfield, 24 kinds of demulsifiers were screened by using the interface generation energy (IFE) module in the molecular dynamics simulation software Materials Studio to determine the ability of demulsifier molecules to reduce the total energy of the oil–water interface after entering the oil–water interface. Neural network analysis (NNA) and genetic function approximation (GFA) were used as technical means to predict the demulsification effect of the Liaohe crude oil demulsifier. The simulation results show that the SDJ9927 demulsifier with ethylene oxide (EO) and propylene oxide (PO) values of 21 (EO) and 44 (PO) reduced the total energy and interfacial tension of the oil–water interface to the greatest extent, and the interfacial formation energy reached −640.48 Kcal/mol. NNA predicted that the water removal amount of the SDJ9927 demulsifier was 7.21 mL, with an overall error of less than 1.83. GFA predicted that the water removal amount of the SDJ9927 demulsifier was 7.41mL, with an overall error of less than 0.9. The predicted results are consistent with the experimental screening results. SDJ9927 had the highest water removal rate and the best demulsification effect. NNA and GFA had high correlation coefficients, and their R2s were 0.802 and 0.861, respectively. The higher R2 was, the more accurate the prediction accuracy was. Finally, the demulsification mechanism of the interfacial film breaking due to the collision of fluorinated polyether demulsifiers was studied. It was found that the carbon–fluorine chain had high surface activity and high stability, which could protect the carbon–carbon bond in the demulsifier molecules to ensure that there was no re-emulsion due to the stirring external force. [ABSTRACT FROM AUTHOR]

This study was the first to examine the mechanical behavior of sediment-bearing methane hydrates (SBMHs) with hydrate abundance up to 80%. The experiment results showed that the stress–strain curves of the SBMH specimens were characterized by the elastic–plastic deformation or plastic–elastic–plastic deformation of the specimens, prominent strain softening, and a rounded head-like trailing peak shape with no obvious stress cusps. Increasing the hydrate content and pore pressure, and reducing the temperature significantly enhanced the peak strength and initial tangent modulus of the specimens, but led to a decline in the peak strain. New correlation equations for initial tangent modulus, peak strength, and peak strain depending on hydrate abundance, pore pressure, and temperature were developed. A modified hyperbolic constitutive model was proposed by introducing a correction term to the Duncan–Chang model that reflects the degree of specimen softening and considering the effects of the hydrate abundance, temperature, and pore pressure. The modified model satisfactorily revealed the strain-softening characteristics of the SBMHs and accurately reproduced the peak strength and strain of all experimental specimens, effectively characterizing the contributions of the hydrate content, pore pressure, and temperature to the stress–strain behaviors of the specimens. • Mechanical properties of high-abundance methane hydrates are investigated. • The effects of hydrate abundance, temperature, and pore pressure are considered. • Changing patterns for the elastic modulus, peak strength and strain are revealed. • Stress-strain curves exhibit strain softening behavior and a rounded peak strength. • A nonlinear constitutive model considering the strain softening effect is proposed. [ABSTRACT FROM AUTHOR]

A novel methodology considering phase behavior and hydrogen bonding association between asphaltene and water was developed to predict the optimal conditions during hydrocarbon recovery from oily sludge (OS) using supercritical CO 2 (SCCO 2). The predicted optimal extraction temperature and pressure for Fuling OS are 23 MPa and 333.15 K, respectively. After performing systematic experimental studies, time was found to positively affect extraction efficiency, whereas temperature and pressure had negative effects beyond 25 MPa and 323.15 K (i.e., the measured optimal conditions of Fuling OS). The extraction efficiency under these conditions reached 11.02%. Compared with unprocessed OS, processed OS had a different crystalline structure, more homogeneous particle size, and lower spectral peak intensity. Additionally, sixteen-carbon chains (C 16) or shorter were recovered more easily than heavier components. The distribution of carbon number in OS was unaffected by the extraction process, indicating that SCCO 2 extraction did not change the hydrocarbon composition. [Display omitted] • A new method was developed to predict optimal extraction conditions. • Promotion and inhibition exist near optimal extraction temperature and pressure. • Extraction time positively affects extraction efficiency. • Particles processed by supercritical CO 2 are more homogenous than unprocessed. • C 16 or lower components can be recovered more easily than heavier components. [ABSTRACT FROM AUTHOR]

Moment invariants are an especially important research topic in pattern recognition. There are many kinds of moment invariants published in the literature already. However, there is a need to further improve them, especially under the noisy environments. In this article, we develop a new set of moment invariants by means of ridgelet function. The ridgelet function is capable of capturing line features in an image, which is a particularly important property in pattern recognition. It is well-known that every curve can be approximated by short line segments, so ridgelet moment invariants should be good at robust pattern recognition. We can prove that this set of moments is invariant to the rotation of 2D images. Experiments show that our proposed ridgelet moment invariants are better than the Gaussian–Hermite moments, the Fourier–wavelet descriptor, and Zernike's moment invariants for one Chinese character database and one 2D shape database. Furthermore, our proposed ridgelet moment invariants can do an excellent job for noise-robust pattern recognition. [ABSTRACT FROM AUTHOR]

Experience and experimental results show that the perceived colour appearance of an object varies with the size of that object or the viewing angle. Based on available visual size‐effect data, it is found that the size effect can be compensated in the CAT16 cone‐like space. Furthermore, it is found that, similar to the von Kries chromatic adaptation, size‐effect correction can be operated independently on the different cone channels. Hence, the size effect can be easily built into the CAM16 model to predict the colour appearance for stimuli of varying sizes. [ABSTRACT FROM AUTHOR]

A comprehensive color appearance model should be capable of predicting color appearance under a wide range of viewing conditions, including related and unrelated colors. The current CAM16 model was designed to predict the appearance of related colors and is in the process of becoming a CIE recommendation, to replace the current CIECAM02 model. This article describes an extension of CAM16 (named CAM20u) for predicting the brightness, hue quadrature, amount‐of‐white, and colorfulness attributes of unrelated colors. Its performance, together with that of other unrelated models, was tested based on the three available datasets. The results show that the CAM20u model significantly outperforms the others, especially for colorfulness and amount‐of‐white. [ABSTRACT FROM AUTHOR]

(We could not place the transducer and the left leg electrode on the pulsation at the same time and thus were unable to directly compare the arterial pulse waveform with other electrocardiogram leads.) C. Synchronous recordings of electrocardiogram lead I and the arterial pulse waveform in the left leg. All the limb leads and precordial leads depend on the left leg electrocardiogram electrode, except for lead I. As a result, we examined the left leg electrode and felt a strong pulsation that we interpreted as arterial pulsation. [Extracted from the article]

Ventilative drying is an essential drying method to protect natural gas pipeline from corrosion and prevent the formation of hydrate. A mathematical model describing the problem of pipelines drying with dehydrated air is developed based on the fundamental principle of mass, momentum, and species conservation in present work. To enhance the accuracy of the model, a new correlation of the evaporation rate of water in pipeline is introduced by taking interfacial resistance into account. Finite volume method (FVM) is employed to discretize the governing equations with first-order upwind scheme for mass and momentum equations and QUICK scheme for species equations. To reduce calculation load, a new solution strategy of semi-implicit method for Sm-linked equations is proposed to solve the nonlinear algebraic equations after the discretization of mathematical model. The results indicate that average absolute deviation between experimental data and the calculations are 8.8% and 8.2% for two cases, respectively. By analysis of dynamic process of the ventilative drying, it is found that the drying process takes place from the ends toward the center of the pipeline. In addition, the results also demonstrate that the nonuniform distribution of the liquid holdup may reduce the service efficiency of dehydrated air at the late period of drying process. Thus, we suggest that the drying process shifts to soak-test stage when the water vapor at the outlet reaches a minimum set value. Finally, a number of influential factors on the drying process are studied. [ABSTRACT FROM AUTHOR]

• A clean dataset tests recycling participation variation with distance. • Participation rates of recycling vary with distance: small, negative, significant. • Frequency of (non-zero) participation does not vary with distance. • Results are inconsistent with cost/benefit models and widespread assumptions. • Results suggest recycling field should use non-static models incorporating phases. The distance of recycling bins from households is often considered important by practitioners, but published evidence for this uses only indirect and self-reported data. This study aims to provide such evidence by obtaining a clean test using measured distances in a walled community with 1200 households with the same building types, local governance, recycling and waste arrangements. The number of deposits each month of food waste for recycling at a designated site are logged via smart-cards allocated per household. The number of days per month that each household deposits showed a highly significant - but small - negative correlation with distance of the bin: fewer householders participate if further away, accounting for 3% of the variation. Surprisingly, there is no variation with distance among those who do participate: their recycling frequency does not vary. This second result is not consistent with the first in terms of cost/benefit concepts assumed by government planners, nor with the static theories of behaviour currently used in waste management research. We recommend that recycling practitioners note the smallness of the contribution of distance to recycling performance, and not overrate it. And we recommend that researchers make better use of non-static models (which model different stages towards behaviour change), which our second result appears to call for. [ABSTRACT FROM AUTHOR]

Vacuum drying is one of the most effective methods to protect submarine natural gas pipes from blockage caused by hydrate and internal corrosion. This article presents a model for analyzing the mass, momentum, and energy transfer processes in pipeline drying with vacuum drying method. Model of the evaporation rate of liquid water is derived from Hertz–Knudsen–Schrage equation. Finite volume method is employed to discretize the governing equations with an upwind implicit scheme in present work, and 2nd order upwind scheme for energy equation is adopted to weaken numerical dissipation. Non-linear algebraic equations after discretization are solved by Newton-Raphson method. Reliability and accuracy of this model are validated via three experimental cases. Numerical results coincide well with the experimental data, and the relative errors of the calculated drying time are 1.7% in Case 1, 1.2% in Case 2, and 5.5% in Case 3. Finally, the dynamic characteristics of the vacuum drying process are analyzed such as dynamic distributions of pressure, temperature, mass flow rate, and liquid holdup. Mathematical model and algorithm developed in present work provide understanding and insights of the vacuum drying process, which aids in determining cost-effective pipeline drying scheme. [ABSTRACT FROM AUTHOR]

2 9 Si Nuclear Magnetic Resonance (NMR) can measure the molecular structure of silicate in oilfield reinjection water. However, noise in 2 9 Si NMR spectra (NMRS) affects the determination of silicate molecular structure type. To solve this problem, a new peak fitting method (Two-step Greedy-Singular Spectrum Analysis-Gaussian Fitting Method, TSG-SSA-GFM) is proposed in this paper. This method first uses TSG to determine the embedding dimension, then uses SSA to determine the characteristic peak position. Finally, GFM is used to calculate the molar ratio of characteristic peaks. The results show that TSG can quickly determine the embedding dimension and reduce computation by at least 50% vs. the global ergodic method. The mean deviation of characteristic peak positions determined by SSA is 0.07 ppm, while Discrete Wavelet Transform (DWT) and Empirical Mode Decomposition (EMD) cannot determine characteristic peaks of 2 9 Si NMRS containing overlapping peak. The average R -squared of Gaussian fitting of 2 9 Si NMRS is 98.4% while Lorentzian is 90.6%. Therefore, this study provides an important method for quantitative analysis of 2 9 Si NMRS. [ABSTRACT FROM AUTHOR]

A thermodynamic model is developed for predicting wax and asphaltene precipitation in crude oil mixtures with up to four phases, i.e. vapor, liquid, wax-rich and asphaltene-rich. The model adopts the experimentally supported hypothesis that asphaltenes precipitate before waxes with decreasing temperature and aggregate as the nucleus of wax crystals. The simplified perturbed chain statistical associating fluid theory (sPC-SAFT) equation of states (EOS) is applied in order to describe phase behavior in crude oils. In this research, a characterization method is proposed for mixtures containing asphaltenes and waxes using the sPC-SAFT EOS. And a correlation is modified for prediction of binary interaction parameter for the sPC-SAFT based on measured binary solid solubilities of twelve n -alkane mixtures. The universal quasi chemical activity coefficient (UNIQUAC) model is used to account for the non-ideality of the wax-rich phase. It is shown that the cloud point and the amount of wax and asphaltene precipitates obtained in the proposed model have an excellent agreement with the experimental data. • Precipitates in crude oils are divided into asphaltene-rich phase and wax-rich phase in the thermodynamic model. • A characterization method for crude oil is proposed using sPC-SAFT EOS. • The correlation of Binary Interaction Parameter for sPC-SAFT is developed based on binary solid solubility. • UNIQUAC method is used to account for the non-ideality of wax-rich phase and sPC-SAFT for vapor and liquid fugacity. [ABSTRACT FROM AUTHOR]

• This paper focuses on daily natural gas consumption forecasting. • A novel hybrid model is developed for daily natural gas consumption forecasting. • The most recent datasets of four cities in three climate zones are collected. • An improved singular spectrum analysis is first proposed. In daily natural gas consumption forecasting, the accuracy of forecasting models is vulnerably affected by the noise data in historical time series. Singular spectrum analysis (SSA) is often introduced into hybrid models for denoising. However, as a deterministic-based algorithm, SSA does not give good results when a time series is contaminated with a high noise level. Considering this fact, this paper proposes an improved SSA (ISSA) that modifies the determination method of subseries selection in the reconstruction stage of SSA. Combining ISSA with long short-term memory (LSTM), a novel hybrid model, ISSA-LSTM, is thus developed. Additionally, for validating the robustness and superiority of ISSA-LSTM, the historical datasets of four representative cities located in three climate zones are collected as the training and testing datasets, and a comparison of ISSA-LSTM with five advanced models is performed. The results reveal that SSA would generate negative values when time series close to zero and the contribution of SSA in improving the forecasting accuracy of LSTM is insignificant. In contrast, ISSA avoids generating negative values and reduces the mean absolute range normalized error (MARNE) of LSTM by a range of 0.86–11.86%. Among the models, ISSA-LSTM achieves the best performance and its MARNEs for London (temperate zone), Melbourne (subtropical zone), Karditsa (subtropical zone), and Hong Kong (tropical zone) are 4.68%, 5.72%, 5.76%, and 14.10%, respectively. The MARNE of the tropical city is higher than that of others, which is caused by the complex natural gas consumption pattern of itself. [ABSTRACT FROM AUTHOR]

Bubble formation in flowing liquid is an important process for wastewater treatment, processing of molten metals, and biological processes. Based on a global balance of force on the bubble, this report describes a new theoretical model for bubble formation during horizontal gas injection into turbulent liquid flow in a vertical tube. This work highlights the importance of choosing the correct drag law in accordance with the bubble size. Five models for drag coefficient are compared, and of these, model III is recommended. Modified detachment criteria are applicable, depending on the liquid velocity. The new analytical model yields good predictions compared with experimental data. Based on the theoretical model, this study investigates the effects of the direction of liquid flow, liquid velocity, gas velocity, and orifice diameter on the bubble formation behavior. [ABSTRACT FROM AUTHOR]

Abstract: Color‐appearance models, CIECAM02 and CAM16, usually include two one‐step chromatic adaptation transforms: a forward (one‐step) transform to convert data from a first illuminant to CIE illuminant E, plus a reverse (one‐step) transform to convert the results from CIE illuminant E to a second illuminant. In practice, however, one‐step chromatic adaptation models, that avoid the use of the intermediate CIE illuminant E, are also employed. Tests using the one‐step CAT16 model indicate failures of both the symmetry and transitivity properties, except in the case where the degree of adaptation D is equal to unity. The magnitude of these failures depends on the specific illuminants selected, and increases as the degree of adaptation decreases. From four possible two‐step CAT16 models, we have identified two that obey the symmetry and transitivity properties, one with slightly better predictions of the experimental corresponding‐color datasets available in the literature, and more consistent with the one‐step CAT16 model. The findings of this article confirm that, for incomplete adaptation, the use of the one‐step CAT is incorrect, and we propose that the use of a two‐step CAT16 model be mandatory for future applications. [ABSTRACT FROM AUTHOR]

• The condensation characteristics in throttle valves with orifice plate throat (OTV) and venturi throat (VTV) are compared. • The condensation position in VTV is ahead of that in OTV, but the ethane condensation rate in OTV is 2.36% higher than in VTV. • The ethane condensation rate rises to 15.4 % and 8.6 % as the outlet section diameter in OTV and throat angle in VTV increase to 27 mm and 80°, respectively. There are differences in spontaneous condensation characteristics in throttle valves with different throat types that remain unknown. Moreover, the effects of the structural parameters on condensation characteristics have not been studied yet. Hence, this paper numerically compares the condensation characteristics of the CH 4 -C 2 H 6 mixture in throttle valves with an orifice plate throat (OTV) and venturi throat (VTV) to reveal the differences. Moreover, this paper discusses the effects of the outlet section diameter of OTV and the throat angle of VTV on condensation characteristics in detail. The results show that the maximum pressure and temperature drops in VTV are slightly lower than in OTV, but the positions corresponding to the minimum pressure and temperature are closer to the throat than in OTV. Hence, the nucleation and droplet growth regions in VTV are 0.0034 m ahead of those in OTV. The maximum liquid mass fraction in OTV is 11.01 % higher than in VTV. As a result, the ethane condensation rate in OTV is 10.62 % higher than in VTV. In OTV, a larger outlet section diameter can promote condensation, in detail, the ethane condensation rate is 9.5 % and 15.4 % under the outlet section diameter of 19 mm and 27 mm. In VTV, the liquid mass fraction increases with increasing throat angle. The ethane condensation rate is higher under a larger throat angle, in detail, the ethane condensation rate is 7.1 %, 7.9 %, and 8.6 % under throat angles of 40°, 60°, and 80°, respectively. [ABSTRACT FROM AUTHOR]

Blending hydrogen into natural gas is a feasible way to transport hydrogen via natural gas pipelines. In hydrogen-blended natural gas (HBNG) pipelines, choking is an essential process that concerns safety issues like condensation and hydrate formation inside valves and the Joule-Thomson (J-T) characteristics like temperature drops, isenthalpic curve (IC), Joule-Thomson coefficient (JTC). However, these two aspects of HBNG differ from those of natural gas, and the differences in inside-valve flow remain unknown, and those in J-T characteristics remain less clear. Given the incapability of the isenthalpic model in obtaining inside-valve flow fields, we conduct a comprehensive study on the effects of hydrogen on inside-valve flow and J-T characteristics of HBNG by combining the computational fluid dynamics (CFD) model and the isenthalpic model. We develop a numerical model by coupling the isenthalpic equations, the conservation equations, the k - ω turbulence equations, and the species transport equations. For the first time, we discuss the effects of hydrogen on the temperature, pressure, and velocity fields of HBNG and evaluate the risks of p - T curves entering vapor-liquid equilibrium and hydrate formation regions. Then, we analyze the effects of hydrogen on ICs and JTCs. Results indicate that with increasing hydrogen mole fraction (HMF), the temperature along the center line rise, the minimum temperature increases roughly linearly, and the corresponding positions shift to the throat in a rough linear law. The JTCs of HBNG roughly linearly decrease with increasing HMF from 0% to 30%. • The inside-valve temperature profile of HBNG rises with increasing HMF. • The position with the lowest temperature shifts to the throat roughly linearly. • The inside-valve p - T curve shifts to the high-temperature side with increasing HMF. • The JTC of HBNG decreases with increasing HMF roughly linearly. • The JTC decreases by about 30% and 50% at HMFs of 15% and 30%, respectively. [ABSTRACT FROM AUTHOR]

In ITER and future fusion devices, the plasma facing surfaces are expected to suffer from the superposition of steady-state and transient heat loads. The extreme high transient heat fluxes cause the deterioration of material surface that increases from roughing to cracking even melting. And, the high heat flux tests on pre-heated tungsten implied that the steady-state heat load induced initial surface base temperature would have great influence on the transient heat flux induced damages. The present efforts tried to explain the mechanism of this phenomenon in view of the thermal-mechanical analysis by means of finite element simulation. The surface temperature and stress-strain distribution and evolution of a cylindrical W/Cu block under superposition of the steady-state heat loads corresponding to base temperature (20–600 °C) and transient heat fluxes (5 ms, 0–900 MW m −2 ) were successfully simulated. The corresponding relations between stress-strain and temperature are compared with the yield strength-temperature relation to analyze the surface event evolution during the heating and cooling phases, which showed how the base temperature influenced the transient heat flux induced damages. The analysis results theoretically identified that the pre-heating by steady-state heat load indeed influenced the transient heat flux induced damages. Typically, no any crack would be generated even under extreme high transient heat fluxes close to the melting threshold if the base temperature exceeded the ductile to brittle transition temperature, and the surface also showed deterioration from roughing to cracking while then roughing with increasing of transient heat flux under a certain base temperature, which were in good agreement with the experiments results. [ABSTRACT FROM AUTHOR]

Operation optimization of natural gas pipelines has received increasing attentions, due to such advantages as maximizing the operating economic benefit and the gas delivery amount. This paper provides a review on the most relevant research progress related to the steady-state operation optimization models of natural gas pipelines as well as corresponding solution methods based on stochastic optimization algorithms. The existing operation optimization model of the natural gas pipeline is a mixed-integer nonlinear programming (MINLP) model involving a nonconvex feasible region and mixing of continuous, discrete, and integer optimization variables, which represents an extremely difficult problem to be solved by use of optimization algorithms. A survey on the state of the art demonstrates that many stochastic algorithms show better performance of solving such optimization models due to their advantages of handling discrete variables and of high computation efficiency over classical deterministic optimization algorithms. The essential progress mainly with regard to the applications of the Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Ant Colony Optimization (ACO), Simulated Annealing (SA) algorithms, and their extensions is summarized. The performances of these algorithms are compared in terms of the quality of optimization results and the computation efficiency. Furthermore, the research challenges of improving the optimization model, enhancing the stochastic algorithms, developing an online optimization technology, researching the transient optimization, and studying operation optimization of the integrated energy network are discussed. [ABSTRACT FROM AUTHOR]

The CIECAM02 color-appearance model enjoys popularity in scientific research and industrial applications since it was recommended by the CIE in 2002. However, it has been found that computational failures can occur in certain cases such as during the image processing of cross-media color reproduction applications. Some proposals have been developed to repair the CIECAM02 model. However, all the proposals developed have the same structure as the original CIECAM02 model and solve the problems concerned at the expense of losing accuracy of predicted visual data compared with the original model. In this article, the structure of the CIECAM02 model is changed and the color and luminance adaptations to the illuminant are completed in the same space rather than in two different spaces, as in the original CIECAM02 model. It has been found that the new model (named CAM16) not only overcomes the previous problems, but also the performance in predicting the visual results is as good as if not better than that of the original CIECAM02 model. Furthermore the new CAM16 model is simpler than the original CIECAM02 model. In addition, if considering only chromatic adaptation, a new transformation, CAT16, is proposed to replace the previous CAT02 transformation. Finally, the new CAM16-UCS uniform color space is proposed to replace the previous CAM02-UCS space. A new complete solution for color-appearance prediction and color-difference evaluation can now be offered. [ABSTRACT FROM AUTHOR]

The de-oiling hydrocyclone is among the most effective devices to recover oil from oily wastewater. In this work, a new model is theoretically developed to predict the separation efficiency of oil droplets in hydrocyclones. According to the analysis of the flow pattern, the droplet dynamics, and oil concentration distribution in the de-oiling hydrocyclone, the differential equation for the new model is established based on the principle of the mass balance of oil droplet. The proposed model can be finally expressed as a simple explicit function including the main geometrical dimensions and operating parameters. The availability of this model is validated by comparison of the calculated grade efficiency with experimental data and other theoretical separation model. [ABSTRACT FROM PUBLISHER]

Cavitation is a widespread hydrodynamic phenomenon. Accurate prediction of cavitating flow is beneficial to the design and maintenance of the hydrodynamic machinery. A new cavitation model reducing the number of parameters needed to obtain satisfactory results is presented and validated. Based on the multiphase flow equation, the mass transfer due to cavitation is expressed as a source term in the gas-phase continuity equation. The mass transfer rate is derived from the assumption that the number of cavitation nuclei per unit volume in the mixture varies linearly with the vapor volume fraction during the evaporation stage. The mass transfer rate also incorporates the simplified Rayleigh–Plesset equation and the critical radius of cavitation nuclei. The new cavitation model considers the influence of non-condensable gas and the molar density of non-condensable gas is the only physical parameter that must be specified. The cavitating flow over a hydrofoil, cavitating flow in a sharp-edged orifice, and the unsteady cavitating flow in a venturi tube were predicted to verify the validity of the new cavitation model. The simulation results of the new model are in good agreement with the experimental results. The new cavitation model predicts cavitation regions and periodic unsteady cavitating flows. • A new cavitation model applicable to various cavitation phenomena is presented. • The content of non-condensable gas should be specified in the cavitation model. • The cavitating flow over a hydrofoil, cavitating flow in a sharp-edged orifice, and the unsteady cavitating flow in a venturi tube were simulated. [ABSTRACT FROM AUTHOR]

This study investigates the vibration control of a plate subjected to moving masses. The plate model reflects the dynamic behavior more accurately than the beam model which is usually used in the existing literature. However, the vibration control of plates subjected to moving masses is also more challenging as more degrees of freedom need to be taken into account. In addition, the measurement of system status and uncertainty problems in practical application is another nodus. In this paper, combining an adaptive sliding‐mode control (ASMC) strategy and a modal coordinate reconstruction (MCR) method, the MCR‐ASMC method is proposed. The MCR method is employed to capture the plate dynamic behavior for feedback to the ASMC. The ASMC strategy realizes vibration control through the adaptive updating of parameters. Numerical results demonstrate the effectiveness of the proposed method and excellent control performance in vibration suppression of moving mass problems. [ABSTRACT FROM AUTHOR]

Hyperspectral face recognition provides improved classification rates due to its abundant information in the face cubes of every subject in hyperspectral face databases. However, it is less popular in face recognition due to its difficulty in data acquisition, low signal‐to‐noise ratio, and high dimensionality. The authors compare five existing descriptors that are frequently used in 2D face recognition, and use collaborative representation classifier (CRC) with two voting techniques for hyperspectral face recognition. Experimental results demonstrate that, for PolyU‐HSFD database, Gabor filter bank‐based features are very robust to both Gaussian white noise and shot noise, and it achieves very competitive classification results. For CMU‐HSFD database, when the noise level is low, histogram of oriented gradients (HOG) yields good classification results. In addition, when the noise level is high, raw facial images without feature extraction perform very well in term of correct classification rate. The local binary pattern and HOG descriptor are very sensitive to noise even though they achieve rather good classification rates if the facial images contain no noise. The best recognition result for the PolyU‐HSFD is 96.4% ± 2.3 and for the CMU‐HSFD is 98.0% ± 0.7. [ABSTRACT FROM AUTHOR]

A mechanical separation process in a de-oiling hydrocyclone is described in which disperse oil droplets are separated from a continuous water phase. This separation process is influenced by droplet breakage and coalescence. Based on experimental data and simulation results in a stirred tank, a modified breakage model, which can be applied to droplet breakage in the de-oiling hydrocyclone, is developed. Then, a simulation model is developed coupling the numerical solution of the flow field in the hydrocyclone based on computational fluid dynamics (CFD) with population balances. The homogenous discrete method and the inhomogeneous discrete method are applied for solving the population balance model (PBM). The investigations show that the numerical results obtained by the simulation model coupled with the modified PBM using the inhomogeneous discrete method are in good accordance with experimental data under a high flow rate. According to this simulation model, the effect of three different inlet designs on the separation efficiency of the de-oiling hydrocyclone has been discussed. The results indicate that the separation efficiency of the de-oiling hydrocyclone can be improved with an appropriate inlet design. [ABSTRACT FROM AUTHOR]

Trihalomethane (THMs) and haloacetonitriles (HANs) are typical and frequently detected carbonaceous (C–) and nitrogenous (N–) disinfection by-products (DBPs) in water treatment, and amine acids (AAs) are important precursors of DBPs. However, previous researches mainly focused on free AAs and few investigations evaluated the DBPs formation potential of combined AAs, especially combined histidine. The formation of THMs and HANs from free and combined histidine and glycine during chlorination was firstly examined and compared in this study with an emphasis on their differences. The impacts of chlorine dose, pH, ammonia nitrogen and bromide were evaluated and mechanistic formation pathways were proposed. In comparison with free AAs, combined AAs generated more chloroform (CF, 125%–671%) but less dichloroacetonitrile (DCAN, 4.66%–87.5%) at all chlorine doses. The effect of solution pH on combined AAs was slighter than that on free AAs. During chloramination, both free AAs and combined AAs generated much smaller amounts of DBPs, especially DCAN (<9.01%), compared with chlorination. At any bromide dose, there was more bromine merging into THMs than DHANs, especially for combined AAs. At the beginning of chlorination, the combined AAs decomposed in three different ways: hydrolysis, decarboxylation and scission, leading to differing amounts of CF and DCAN compared with the free AAs. [ABSTRACT FROM AUTHOR]

Transient cavitating flow is a dangerous condition in the operation of large drop crude oil pipelines. Accurately predicting the high pressure generated by cavity collapse is the premise of analyzing and formulating pipeline safety management and control strategies. A new numerical simulation method for one dimension cavitating flow in crude oil pipelines considering the effect of unsteady friction was proposed. The unsteady friction (UF) term is coupled to the classical discrete gas cavity model (DGCM) for modeling the cavitating flow, and the proposed model is called UF-DGCM. The method of characteristics (MOC) is used to solve the UF-DGCM. The validity of the model has been verified with experimental data. The pipeline length of the two test cases is 37.23 m and 15.22 m, respectively, and the pipeline diameter is 22.1 mm and 20.0 mm, respectively. For the two test cases, the accuracy of the prediction results is improved by 6.7% and 4.4%, respectively. A case study of cavitating flow caused by pump shutdown in a pipeline with a length of 35 km and a diameter of 738 mm was performed using UF-DGCM, and the effects of water hammer wave speed, crude oil vapor pressure, and pump shutdown time on cavitating flow were analyzed. The results show that the maximum pressure peak is dependent on the water hammer wave speed. About the increase in the wave speed value of 200 m/s will lead to an increase in the maximum pressure head value of 10.1 m. The increase of pump shutdown time will inhibit the growth of cavities, and increasing the pump shutdown time by 4 s will shorten the existence time of cavities by about 3 s. The extension of the pump shutdown time will prevent cavitating flow. The proposed improved model is more suitable for transient cavitating flow analysis, and the results of flow parameters research will be helpful to prevent cavitating flow in crude oil pipelines. • A discrete gas cavity model coupling unsteady friction is stated and validated. • About the increase in the wave speed value of 200 m/s will lead to an increase in the maximum pressure head value of 10.1 m. • Increasing the pump shutdown time by 4 s will shorten the existence time of cavities by about 3 s. • The extension of the pump shutdown time will prevent cavitating flow. [ABSTRACT FROM AUTHOR]

Gas solubility in water under hydrate-liquid water (H-L w ) two-phase equilibrium is the foundation of gas hydrate kinetic study. It is significant for the simulation of multiphase pipeline flow, the stability and amount evaluation of natural gas hydrate resources in deep water as well as gas storage and separation. In the current work, thermodynamic models were established by combining van der Waals-Platteeuw theory with PR, VPT and TB equations of state separately, named as Model VPR, VVPT and VTB, to predict methane solubility in water under H-L w equilibrium. The Henry’s law was also included for comparison. Available experimental data in literature were collected to test the applicability of these equations of state. In order to improve the predicting accuracy, binary interaction parameters in the asymmetric contribution term of non-density-dependent (NDD) mixing rules were modified. Good agreements between predicted and experimental data were obtained by Model VVPT with the modified NDD mixing rules. [ABSTRACT FROM AUTHOR]

Ferromagnetic pipelines provide a major means for the conveyance of oil and natural gas. The self-magnetic leakage field (SMLF) generated by ferromagnetic pipelines has therefore attracted considerable attention in the field of pipeline examination and defect detection. This paper has the objective of analysing the magnetomechanical effect, which can be observed in the geomagnetic field, by establishing a mathematical model of the SMLF based on the theory of magnetic dipoles and the magnetomechanical effect, and to discuss the influence of factors such as the outer diameter, the geomagnetic field intensity, the operating pressure, etc. The results show that the length of oil and gas pipelines can be considered as infinite for the calculation of the SMLF. In addition, both the total flux density and the gradient modulus of the SMLF are shown to reach their maximum values above the pipeline. The parameter analysis indicates that the pipeline diameter and the height of the covering soil are two crucial factors in determining the SMLF. Finally, in an experiment to test the model, the error between the theoretical calculation and the actual measurement was 4.6%. Therefore, the model proposed in this paper can provide technical support for the calculation of the SMLF induced by pipelines, which has significance for the inspection of pipeline locations and pipeline defects. [ABSTRACT FROM AUTHOR]

The de-oiling hydrocyclone belongs to the most effective devices to recover oil from oily wastewater. An improved multiphase computational fluid dynamics (CFD) model is developed for simulating oil-water separation in a de-oiling hydrocyclone. This model approach uses the Reynolds stress model to resolve the turbulent and the modified mixture model with a new viscosity correlation of oil-in-water (O/W) emulsions. This modified model of emulsion viscosity based on the power law equation and experimental data of three types of crude oil is introduced to predict the viscosity of O/W emulsions. A comparison between experimental and predicted values of separation efficiency demonstrates that multiphase simulations with the modified model of viscosity provide a better accuracy than CFD models associated with original rheological models. This improved CFD model can be further applied in developing new designs in the future. [ABSTRACT FROM AUTHOR]

The least squares method for computing colorimetric weighting tables is presented and its connection with the optimum weights method is investigated. Each requires solving three linear systems of equations with the same coefficient matrix but three different right hand side vectors. It is shown that the two methods have nearly the same performance when the wavelength interval of the data is large. The two methods however, will perform differently when Δ λ is small. Comparisons are also made between the least squares method, the optimum weights method, the zero- and second-order weighting tables, and the ASTM weighting tables, both the original 1985 tables and the new 2013 Tables V and VI. The results show that the least squares method is the best for measurement intervals equal to or lower than 10 nm, and is competitive with the optimum weights method for 20 nm steps. The results presented in this article will contribute to the work of CIE Technical Committee TC1-71 Tristimulus Integration as it seeks to make recommendations for the calculation of tristimulus values. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 125-142, 2016 [ABSTRACT FROM AUTHOR]

Water-in-oil (W/O) emulsions are very common in the petroleum industry, and their viscosities are the principle parameters for the operation design. Typical correlations composed by one or two factors cannot always fit the apparent viscosity of W/O emulsions very well, especially when applied to the crude oil/water emulsions. The viscosities of W/O emulsions, which were made from three kinds of crude oil, were measured by Anton Paar MCR302 viscometer at atmospheric pressure with different temperatures as well as shear rates. The experiment results indicate that W/O emulsion would exhibit Newtonian characteristic when water content is no higher than 0.2 and non-Newtonian characteristic otherwise. According to the experimental data, a modified correlation based on the Broughton–Squires model and Ronningsen model was introduced to predict the viscosity of W/O emulsions, and the comparison results showed that the new modified correlation has better accuracy than the original models. [ABSTRACT FROM PUBLISHER]

Parathyroid hormone (PTH) suppresses the expression of the bone formation inhibitor sclerostin ( Sost) in osteocytes by inducing nuclear accumulation of histone deacetylases (HDACs) to inhibit the myocyte enhancer factor 2 (MEF2)-dependent Sost bone enhancer. Previous studies revealed that lipoprotein receptor-related protein 6 (LRP6) mediates the intracellular signaling activation and the anabolic bone effect of PTH. Here, we investigated whether LRP6 mediates the inhibitory effect of PTH on Sost using an osteoblast-specific Lrp6-knockout (LRP6-KO) mouse model. An increased level of Sost mRNA expression was detected in femur tissue from LRP6-KO mice, compared to wild-type littermates. The number of osteocytes expressing sclerostin protein was also increased in bone tissue of LRP6-KO littermates, indicating a negative regulatory role of LRP6 on Sost/sclerostin. In wild-type littermates, intermittent PTH treatment significantly suppressed Sost mRNA expression in bone and the number of sclerostin+ osteocytes, while the effect of PTH was much less significant in LRP6-KO mice. Additionally, PTH-induced downregulation of MEF2C and 2D, as well as HDAC changes in osteocytes, were abrogated in LRP6-KO mice. These data indicate that LRP6 is required for PTH suppression of Sost expression. [ABSTRACT FROM AUTHOR]

It is essential to evaluate the effect of gas bubbles rising in deep water from the place where thermodynamic conditions are favorable for gas hydrates formation. Considering the bubble surface morphology, a gas bubble fate simulation model was established which integrated bubble hydrodynamics, gas dissolution, the thermodynamic and kinetic stability of gas hydrates. Hydrate-coated area ratio was a key parameter. The model was applied to simulate methane bubbles in 1500–5000 μm radii released at 1000–2000 m in Monterey Bay Canyon and South China Sea. Reliable simulation results were helpful for further research on deep water environment. [ABSTRACT FROM AUTHOR]

We used five samples of super heavy oils collected in China to prepare 15 water-in-oil emulsions, with water cuts 10%, 20%, and 30%. We determined the viscosity of the emulsions at 30°C-75°C. Generally the viscosity of the studied emulsions is in the range 401-75200 mPa·s. Based on the experimental data, we propose a new rheological model for water-in-super heavy oil emulsions based on the Kalra model, introducing a term characterizing the dependence of the relative error on the water cut in the emulsion. The absolute average error in predictions according to the proposed model was 17.36%, which is 6.37% lower than in the original Kalra model. [ABSTRACT FROM AUTHOR]

Scanning electron microscopic (SEM), nitrogen absorption-desorption, and thermogravimetric experiments were conducted on one fresh 4A zeolite and three regenerated 4A zeolite samples taken from the top, middle, and bottom of a natural-gas dehydration bed. The results showed that parts of the regenerated zeolite are blocked due to collapse of the zeolite structure. As a result, the specific surface area, average pore volume, and average pore diameter of regenerated zeolite taken from the middle of the dehydration bed are less by about 59.15, 68.36, and 32.12%, respectively, than those of fresh zeolite. Because water molecules cannot enter the internal pores due to blockage caused by collapse of the zeolite structure, the gas-dehydration performance of the regenerated zeolites is reduced. Thermogravimetric analysis of zeolites that adsorbed water showed that the water-adsorption performance of the regenerated zeolites is 35.53% less and the hydrocarbon-adsorption performance of these zeolites is 18.95% greater than those of fresh zeolite. [ABSTRACT FROM AUTHOR]

Non-contact pipeline magnetic testing (NPMT) is a novel and non-destructive technology based on the metal magnetic memory (MMM) method, which can detect pipeline defects under trenchless conditions. There is a peak on the gradient modulus of the ground leakage magnetic field (GLMF), which is a signal characteristic of a defect. In this study, the physical principles of this technology were first discussed. Next, a spatial distribution model of the GLMF was built based on the theories of magnetic charge and magnetic dipole, which indicates the quantitative relationship between the defect and GLMF. The effects of the model parameter values on the gradient modulus were also discussed. The reliability of the model was verified by comparing the field testing signal with the model calculated value. Directions of further research are formulated, including factors affecting the model accuracy and the classification of defects. [ABSTRACT FROM AUTHOR]

Chronic cerebral hypoperfusion may cause cognitive impairment, but the underlying neurobiological mechanism is poorly understood. In this study, we investigated whether clonidine, an α 2 -adrenergic receptor agonist, could play neuroprotective role against chronic ischemic brain injury and the potential mechanism. Rats were subjected to permanent bilateral occlusion of the common carotid arteries (two-vessel occlusion, 2VO). Three weeks later, rats were administrated with 0.05 mg/kg clonidine (intraperitoneal injection, i.p.) for 7 days. Cognitive function was evaluated by Morris water maze (MWM). Immunofluorescence and western blots were used to detect the protein levels. Our results showed that the cognitive function was partially impaired, and the expression of neuronal nuclei (NeuN), glutamic acid decarboxylase 67 (GAD67) and γ-aminobutyric acid-B receptor 1 (GABA B R1) in hippocampal CA1 area was attenuated after 2VO, which were not observed in CA3 and dentate gyrus (DG). Administration of 0.05 mg/kg clonidine (i.p.) for 7 days could improve cognitive function and the expression of NeuN, GAD67 and GABA B R1 in CA1, but did not affect the protein levels in CA3 and DG. These findings demonstrated that clonidine could ameliorate cognitive deficits and neuronal impairment induced by chronic cerebral hypoperfusion via up-regulation of GABA B R1 and GAD67 in hippocampal CA1. [ABSTRACT FROM AUTHOR]

Taking the X80 steel used in the second West-East Pipeline Project (WEPP II) as a study object, this paper researched the effects of Cl- and SO42- with different concentration(wt% ) on internal corrosion behavior of X80 pipeline steel in stimulated solution for pigging product, discussed the nternal corrosion mechanism of WEPP II by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) experimental. The results showed that, in the stimulated solution only conaining different Cl- mass fraction, the polarization curves of X80 pipeline steel have typical characterstics of active dissolution, the corrosion current density(icorr) and the internal corrosion rate of X80 teel increases along with the increase of Cl- mass fraction; in the stimulated solution containing both 0. 05% Cl- and different SO42- mass fraction, the polarization curves of X80 pipeline steel also have typical characteristics of active dissolution, but the internal corrosion rate firstly increases and then decreases with the increase of SO42- mass fraction. When the mass fraction of SO42- is 0.50%, the icorr reaches the maximum value while polarization resistance reaches the minimum value, and the corrosion behavior of X80 steel is the most serious at this time; when the stimulated solution contain both Cl- and SO42-, the corrosion potential of X80 steel decreases while the icorr increases than the stimulated solution only containing Cl-, with the increase of SO42- mass fraction; when the stimulated solution contain both Cl- and SO42-, with the increase of SO42- mass fraction, SO42- can adsorb on he metal surface faster than Cl-, which decreases the corrosion aroused by Cl-. [ABSTRACT FROM AUTHOR]

Previous research demonstrated that ozone dosed before biological activated carbon (BAC) filtration reduces the formation of disinfection by-products (DBPs) upon subsequent chlorination. The current work aimed to evaluate the impact of terminating this pre-ozonation on the ability of the BAC to remove the precursors of N-DBPs. More N-DBP precursors passed into the post-BAC water when the pre-ozonation was terminated, resulting in greater formation of N-DBPs when the water was subsequently chlorinated, compared to a parallel BAC filter when the pre-ozonation was run continuously. Moreover, the N-DBP formation potential was significantly increased in the effluent of the BAC filter after terminating pre-ozonation, compared with the influent of the BAC filter (i.e. the effluent from the sand filter). Therefore, while selectively switching pre-ozonation on/off may have cost and other operational benefits for water suppliers, these should be weighed against the increased formation of N-DBPs and potential associated health risks. [ABSTRACT FROM AUTHOR]