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An interval robust optimization method is suggested to improve the robustness and performance of the process or product in design. A general uncertain robust optimization problem is considered in which the objective function and constraints are both nonlinear and uncertain, and the uncertainties of design variables and uncertain parameters are all included and depicted by the interval model. A nonlinear interval number programming method is introduced to solve the robust optimization model, in which the uncertain objective function is described by a pair of deterministic functions, and the uncertain constraints are converted to deterministic constraints on the basis of the reliability-based possibility degree of interval. The method is then applied to several heat transfer problems for performance optimization of the heat transfer processes while guaranteeing the robustness of the optimal design. [ABSTRACT FROM AUTHOR]

Water tanks have been built for decades and likely deteriorated over time. To ensure its integrity, Unmanned Aerial Vehicle (UAV) e.g. drones with cameras are used for inspecting the elevated tanks and the images are collected for detecting defects such as cracks. To automatically detect and segment the defect in images, Mask Regional Convolutional Neural Network (Mask-RCNN) the latest convolution neural network model is trained with the real-world infrastructure inspection images. The trained model has been applied to crack detection and segmentation for a water tower of 50 meters height and storage of 500 m3. The images are used to construct a 3D mesh model by photogrammetry technology. The 3D model with annotated cracks enables intuitive visualization and quantitative assessment of 1704 detected cracks, which are evaluated in range of 2 mm to 10 mm wide with total crack length of 77.6 m and total crack area of 0.28 m2. [ABSTRACT FROM AUTHOR]

Workload control is a production planning and control concept designed to meet the need of the make-to-order industry. In this paper, a multi-agent workload control methodology that simultaneously addresses due date setting, job release and scheduling is proposed. To be consistent with just-in-time production, the objective of minimizing weighted job earliness and tardiness is used. Two new rules are developed, by introducing a feedback mechanism, to set job due dates dynamically. These two new rules implicitly include job pool times and, thus, eliminate the need to estimate job pool times in the presence of workload control. At the critical norm defined in this paper job release control can reduce average job flowtime and work-in-process inventory, without worsening earliness and tardiness, and lead-time performances. The proposed methodology is implemented in a flexible job shop environment. The computational results indicate that the proposed methodology is very effective for production planning and control in make-to-order companies. In addition, the proposed methodology is extremely fast and can be implemented in real time. [ABSTRACT FROM AUTHOR]

The hot rolling production scheduling problem is an extremely difficult and time-consuming process, so it is quite difficult to achieve an optimal solution with traditional optimization methods owing to the high computational complexity. To ensure the feasibility of solutions and improve the efficiency of the scheduling, this paper proposes a vehicle routing problem (VRP) to model the problem and develops an easily implemented hybrid approach (QPSO-SA) to solve the problem. In the hybrid approach, quantum particle swarm optimization (QPSO) combines local search and global search to search the optimal results and simulated annealing (SA) employs certain probability to avoid getting into a local optimum. The computational results from actual production data have shown that the proposed model and algorithm are feasible and effective for the hot rolling scheduling problem. [ABSTRACT FROM AUTHOR]

This article proposes an algorithm for managing and deploying manpower (equipped with adequate measuring instrument) to a statistical process control (SPC) scheme so that the resultant control chart (referred to as M-chart) minimizes the expected total cost C total incurred in the implementation of SPC. Unlike in the economic chart designs, most input specifications required by the design of an M-chart can be easily determined by practitioners. The design of an M-chart also takes into account the probability distribution of the random process shifts. The results of an example and a comprehensive study show that the M-chart can reduce the total cost by about 66%, on average, compared with the conventional control charts. It is also found that, in most SPC schemes, the allocated manpower is far less than needed and, consequently, the total cost can be significantly reduced by making some managerial arrangement to increase SPC manpower. Some useful guidelines are provided in this article to aid the management and determination of the appropriate amount of manpower for a particular application. Even though the M-chart is discussed in detail only for the chart detecting mean shifts, the general idea can be applied to many other charts (e.g. the CUSUM and EWMA charts) and to monitoring both process mean and variance. [ABSTRACT FROM AUTHOR]

Both a similarity coefficient method (SCM)-based algorithm and meta-heuristics have been widely applied to various cell formation problems; however, few studies have explored the combination of the two methods. This paper addresses a hybrid algorithm, in which, based on the initial solution produced by a new SCM-based hierarchical clustering method, a fast and effective tabu search approach is presented to solve cell formation in group technology (GT). The proposed algorithm is applied to several problems from literature and a group of the randomly generated instances with alternative process plans and compared with simulated annealing (SA) and other TS; the results demonstrate that the proposed algorithm is available and efficient for cell formation in generalized GT. [ABSTRACT FROM AUTHOR]

A dynamic model of a flexible manufacturing system (FMS) is considered based on the information characteristics of system infrastructure. According to the physical architecture and working requirements, a software framework for FMS modelling and simulation is proposed to describe the parallel flow of different work-pieces in the shop. The model is based mainly on the concepts of both object-oriented programming and high-level Petri net methods. A material transportation protocol is designed to realize the respective processing of routine orders of work-pieces within the main resources of the FMS shop. Using a specially designed protocol, a fully automated job shop FMS can be achieved. An FMS simulation tool that can show the dynamic process of all the system resources during task execution is finally introduced. [ABSTRACT FROM AUTHOR]

An algorithm was developed for the optimization design of control charts based on the probability distribution of the random process shifts (e.g. mean shift). The design objective was to minimize the overall mean of Taguchi's loss function per out-of-control case (denoted as ML) by adjusting the sample size, sampling interval and control limits of the chart in an optimal manner. The optimal chart was therefore named as the ML chart. A three-phase operational scenario for statistical process control (SPC) was also proposed to design and operate the ML chart. The probability distribution of the mean shifts can be modelled by a Rayleigh distribution based on the sample data of the mean shifts acquired in the three-phase scenario. Unlike in the economic control chart designs, the design of the ML chart only requires a limited number of specifications that can be easily determined. The results of the comparison studies show that the ML chart is significantly superior to the Shewhart control chart in view of overall performance. Although the ML chart was discussed in detail only for the chart, the general idea can be applied to many other charts such as CUSUM and EWMA. [ABSTRACT FROM AUTHOR]

An acceptance control chart (ACC) is used to monitor certain processes, in which the natural dispersion of the process is much less than the specified tolerance in design. Typical examples are the processes subject to tool wear. This article presents an adaptive acceptance control chart (AACC). Its sample size can be adjusted during the process control, so that the average number of measurements may be significantly reduced. AACC can also minimize a linear combination of the type I and type II errors, based on the user's specifications. A computer program has been developed to aid the off-line design of AACC. [ABSTRACT FROM AUTHOR]

Zinc oxide thin films were deposited on Si (100) substrates using RF magnetron sputtering by adjusting sputtering power. The film properties were characterized by scanning electron microscopy with energy dispersive X-Ray spectroscopy, X-ray diffraction spectrometer and photoluminescence spectroscopy. Intrinsic defects could be adjusted just by modifying the sputtering power. Variation of Zn to O ratio, defects and their relative concentration of the films with the sputtering power were investigated in details. [ABSTRACT FROM AUTHOR]

In this study, the effects of linoleic acid on the growth, photosynthetic activities and oxidative system of the invasive cyanobacteriumCylindrospermopsis raciborskiiwere investigated. The results indicated that linoleic acid decreased the growth rate and chlorophyllaconcentration inC. raciborskiiafter 48 h incubation. The maximum photochemical efficiency (Fv/Fm) of photosystem II (PSII) and maximum relative electron transport rate (ETRmax) decreased significantly at concentrations higher than 1 mg L−1. However, non-photochemical quenching (NPQ) significantly increased when cultured at concentrations of 0.5, 1, 2 and 4 mg L−1. PSII electron transfer rate and chlorophyllafluorescence transients appeared to be affected after the cells were exposed to higher concentrations of linoleic acid; the density of the reaction centres (RCs), quantum energy flux ratios and the performance index on absorption basis decreased, but absorption flux per RC and dissipated energy flux per RC increased. Malondialdehyde content, superoxide dismutase and catalase activities were enhanced when exposed to 2 and 4 mg L−1of linoleic acid. This suggests that the blockage of electron transport on the donor and acceptor sides of PSII is the mechanism responsible for the toxicity of linoleic acid in PSII ofC. raciborskii. [ABSTRACT FROM AUTHOR]

A numerical and experimental study has been carried out on the heat transfer and fluid flow in two types of welded plate heat exchangers (PHEs). A new approach providing a proper clearance between two adjacent corrugated plates is proposed to improve the mesh quality around the contact points. The clearance value and the influence on the mesh quality and computational results are carefully studied. The results show that a relative clearance of 0.02 is proper. The computational fluid dynamics (CFD) results agree with the experimental results with a deviation of 15%. The proposed approach is proved effective and practical because it can increase the grid quality without losing the accuracy of the results. This paper shows that CFD is a reliable tool for studying the effects of various geometrical configurations on the optimum design of a PHE. [ABSTRACT FROM AUTHOR]

Interfacial stresses, electric fields, and electric displacements of a piezoelectric unsymmetrical bi-layer orthotropic laminate are presented. A state space equation for orthotropic piezoelectric material is derived from three-dimensional piezoelectric elasticity directly. With the application of the transfer matrix and recursive solution approach, a strong solution for the unsymmetrical piezoelectric generalized plane strain bi-layer laminated structure is sought after considering all elastic and piezoelectric constants of materials. Electromechanical boundary layer effect is identified quantitatively at free edges. To facilitate the discussion on the results, the corresponding calculations from finite element models are compared with those of the strong solution. [ABSTRACT FROM AUTHOR]

The growth and alkaline phosphatase (ALP) activities of Sprague Dawley(SD) rat osteoblasts cultured in the nano-hydroxyapatite/polyetheretherketone (n-HA/PEEK) composite extracts and on the surfaces of these composites were investigated in this study. The osteoblasts of 24-h-old SD rats were cultured by modified enzymatic digestionin vitro. The ALP activities of the SD osteoblasts cultured in n-HA/PEEK composite extracts were measured and the mineralisation was studied by alizarin red staining. The morphological characteristics of the SD osteoblasts incubated on the n-HA/PEEK composite surfaces were observed by scanning electron microscopy and the ALP activity was also detected. The results showed that the n-HA/PEEK composites have good cytocompatibility with the SD osteoblasts and there were no obvious differences between PEEK and n-HA/PEEK composites in ALP activities and mineralisation of the SD osteoblasts cultured in their extracts. N-HA/PEEK composites could promote the growth of the SD osteoblasts on the surfaces of them and the improvement was related to the content and uniform distribution of n-HA in the n-HA/PEEK composites. The 5 vol.% n-HA/PEEK composites was promising to be used for bone substitute materials. [ABSTRACT FROM PUBLISHER]

The estimation of the wall parameters is important in through-the-wall radar imaging (TWRI). Ambiguities in the wall characteristics, including wall thickness, permittivity, and conductivity, will distort the imaging and shift the target position. To obtain a quick and accurate estimation of wall parameters, an efficient method based on machine learning is proposed. The estimation problem is converted to a regression problem. A map between wall parameters and the received signals is established and is regressed as a linear formulation after machine learning; in this manner, the wall parameters can be estimated in few seconds. The measurement results demonstrate that the estimated approach has the advantages of high precision and low computational time. The influence of the size, the location, the number of the targets and the length of the wall, the sampling interval, and noise on the estimation problems is discussed, and the image entropy is given to verify the effectiveness of the estimation values. The results based on support vector machines and least-square support vector machines (LS-SVMs), which are both machine-learning approaches, are compared. The comparison results reveal that the LS-SVM-based method can provide comparable performances in terms of accuracy and convenience but poor performances in terms of generalization and robustness. [ABSTRACT FROM AUTHOR]

Shallow oil is gaining more and more attentions worldwide due to its low cost. However, it is easy to form heavy oil in shallow layers. The wide varieties of oil make research on this subject difficult and oil densification mechanisms are usually controversial. Therefore, the geochemical characteristics of both heavy and light oil in shallow layers are compared and studied comprehensively. Research is conducted on the physical properties, group compositions, and diverse biomarkers. Most shallow oil samples exhibit high densities and low freezing points, which show low-sulfur biodegradation environment. With respect to group compositions, asphalts are more prevalent in the sag center. At different oil densification stages, tricyclic and tetracyclic terpanes are found to increase when viscosity is more than 1000 cp, and decrease when viscosity is less than 1000 cp. Pr/nC17has similar characteristics. The changes in the contents of n-alkanes and tricyclic terpanes are found to be diametrically opposed when the oil viscosity increases. Underground water and fault systems are found to be the most important factors of oil densification in shallow oil reservoirs. The research on the geochemical characteristics of shallow oil is important to find better development methods and to select high-quality oil. [ABSTRACT FROM AUTHOR]

BiOCl/amidoxime fibre composite photocatalysts have been successfully prepared via ions chelating on fibre. The structure and composition of the product were characterised by XRD, EDS, SEM, FT–IR, XPS and TG. The results indicated that BiOCl was successfully immobilised on the modified commercial fibres. Photocatalytic testing showed that the BiOCl/amidoxime fibre composite exhibited an excellent recycling performance owing to the coordination interactions between BiOCl and amidoxime fibre. [ABSTRACT FROM AUTHOR]

Traditional geochemical methods to correlate oil and source are not quite fit for too many layers in steep offshore regions. Therefore, more biomarkers and new methods are needed to finish more complicated correlations. Resources in Chengbei Beach zone are generally shallow and high-quality light oil. There are two hydrocarbon source sags and many oil-source layers, and the sources are still disputed. More parameters are used to correlate oil source (i.e., relative group compositions, δ13C, steroids, hopanes, and terpenoids). Some special methods are found, such as the triangular chart of aromatic, asphalt, and saturated hydrocarbon, and the comprehensive use of gammacerane, hopance, and tricyclic terpanes. It is found that there are mainly three oil types. The first type mainly derives from source rocks in Es3, the second type from Es1, and the third type is their mixture. These three oil types are found to have regional features. [ABSTRACT FROM PUBLISHER]

A predator-prey discrete-time model with Holling-IV functional response and distributed delays is investigated in this paper. By using the comparison theorem of the difference equation and some analysis technique, some sufficient conditions are obtained for the permanence of the discrete predator-prey system. Two examples are given to illustrate the feasibility of the obtained result. [ABSTRACT FROM AUTHOR]

In order to investigate the room temperature influence of creep on ballastless track fastening buckle pressure loss, the research on the impact of the creep on loss in the toe load of WJ-7 ballastless track was carried out in the study. Respective tests were carried out for two groups of fasteners (five sets of fasteners for each) with unchanged deformation of fasteners and unchanged initial toe load of fastening, embedded with the pressure sensor and stress sensor in the positions corresponding to the assembled fasteners to measure the tow load of fastening. Under the circumstance that certain buckle load was kept, the changes in displacement of T bolts and T nuts were used to indicate the creep deformation of the elastic bar, and the creep rule of the fastener and its impact on the tow load of fastening under two circumstances were compared and analysed. [ABSTRACT FROM AUTHOR]

By using the first principles based on the density functional theory, the adsorption properties of hydrogen sulphide on the graphene surface are studied in this paper. The structures and the electronic properties are calculated by the generalised gradient approximation. The adsorption energies of hydrogen sulphide adsorbed on graphene surface at the B, T and H sites are determined as −0.356, −0.410 and −0.332 eV, respectively. The results show that hydrogen sulphide adsorbed at the T site is stable, while H site is the most unstable adsorption site owing to the maximum absorption energy. When hydrogen sulphide is adsorbed on graphene surface, the band gaps of B, T and H sites are respectively 3.749, 3.889 and 3.589 eV so that the graphene is no longer a kind of conductor compared with clean graphene. [ABSTRACT FROM AUTHOR]

An investigation of frequency selective surface made from composite material with cross and Jerusalem cross patches for C band application is presented. The design method selection and its basic theory for analysing the frequency selective surface are introduced. The simulated results from the simulation and measurement results of a designed frequency selective surface array obtained in an anechoic chamber are presented. Their comparison shows a good agreement. The designed composite material frequency selective surface presented in this paper has good electromagnetic characteristics. The 5 dB transmission bandwidth of a single layer cross frequency selective surface is 1 GHz. The double layer frequency selective surface has a better transmission bandwidth than the single one while the Jerusalem cross frequency selective surface design also performs well in terms of frequency responses. [ABSTRACT FROM AUTHOR]

In order to improve the efficiency of thermal parameters back analysis in the application of practical engineering, the orthogonal numerical test for the back-analysed parameters was designed by using Taguchi method of orthogonal tests. According to the test results, the response surface model about temperature field was built. With the combination of the building model of response surface and the genetic algorithm, the back-analysed parameters were calculated efficiently. The method has been used successfully in Muli river Lizhou hydropower station RCC arch dam field rolling test RCC thermal parameters back analysis. The calculation results of application example showed that the proposed method is with less computation and higher efficiency, the parameters obtained from back analysis by using response surface genetic algorithm are reasonable. [ABSTRACT FROM AUTHOR]

Oil in extremely shallow layers gains more attention worldwide as oil price declines. Oil sand is abundant in shallow layers of Chunfeng Oilfield, from 0 m outcrop to 500 m depth. Most cores are so loose that they cannot effectively subject to experiment. To this effect, some special measures are taken to evaluate oil sand, including thermal property analysis, seepage flow analysis, and nuclear magnetic resonance (NMR) experiments. It is found that NMR and thermal properties are new and effective measures to evaluate oil sand in heavy oil reservoirs. Useful properties such as thermal and seepage properties and flushing efficiency are analyzed in this study. These oil sands are found to possess not only superb physical properties, but also excellent thermal conductivity, which is advantageous for common steam drives and steam-assisted gravity drainage. The experiments also prove that even after a lengthy time of steam drive, oil saturation still remains high. Extremely shallow oil sand shows very favorable potential. Thorough analysis and evaluation of oil sand characteristics benefit exploration and development as well as further study of basic petroleum energy theories. [ABSTRACT FROM PUBLISHER]

Distillers' grains are a co-product of ethanol production. In China, only a small portion of distillers' grains have been used to feed the livestock because the amount was so huge. Nowadays, it has been reported that the distillers' grains have the potential for fuel ethanol production because they are composed of lignocelluloses and residual starch. In order to effectively convert distillers' grains to fuel ethanol and other valuable production, sodium hydroxide pretreatment, step-by-step enzymatic hydrolysis, and simultaneous saccharification and fermentation (SSF) were investigated. The residual starch was first recycled from wet distillers' grains (WDG) with glucoamylase to obtain glucose-rich liquid. The total sugar concentration was 21.3 g/L, and 111.9% theoretical starch was hydrolyzed. Then the removed-starch dry distillers' grains (RDDG) were pretreated with NaOH under optimal conditions and the pretreated dry distillers' grains (PDDG) were used for xylanase hydrolysis. The xylose concentration was 19.4 g/L and 68.6% theoretical xylose was hydrolyzed. The cellulose-enriched dry distillers' grains (CDDG) obtained from xylanase hydrolysis were used in SSF for ethanol production. The ethanol concentration was 42.1 g/L and the ethanol productivity was 28.7 g/100 g CDDG. After the experiment, approximately 80.6% of the fermentable sugars in WDG was converted to ethanol. [ABSTRACT FROM AUTHOR]

We focus on the impact of migrants’ remittances on consumption patterns in China. Using a large homogenous sample of rural households surveyed in 2001 and 2004, we find that remittances are spent on nonhousing consumption expenditures at the margin, virtually dollar-for-dollar, when we instrument remittances and local employed earnings using proxies of social networks. Our findings are robust to intra-household division of labour and to fixed-effect for the county in which the respondents are registered. These results imply that rural households largely take remittances as permanent income and are consistent with the prevalence of circular and repeat migration in China. [ABSTRACT FROM PUBLISHER]

Polyparaphenylene/Li0.5Ni0.5Fe2O4 (PPP/LiNi-ferrite, Li0.5Ni0.5Fe2O4 and LiNi-ferrite were used interchangeably) nanocomposites were synthesised using an in situ compounding method, and their thermoelectric (TE) properties were measured. Compared with single phase LiNi-ferrite, nanocomposites have significantly enhanced electronic transfer capability and substantially lowered thermal conductivity. The low thermal conductivity of the added PPP and the very large boundary between the conductive polymer and the oxide nanoparticles play a dominant role on the thermal conductivity reduction. The figure of merit ZT of the PPP/LiNi-ferrite nanocomposite has been improved several orders in a wide temperature range from 300 to 850 K. Fabrication of nanocomposites consisting of electrically conductive polymer and oxide nanoparticles may provide a promising way for realising high ZT TE performance. [ABSTRACT FROM AUTHOR]

Objective To assess the prevalence of musculoskeletal symptoms at four different anatomical sites and the impact of menopause, age, and other factors on musculoskeletal symptoms. Methods Generally healthy women aged 35-64 years were recruited from a general community in Beijing, People's Republic of China. Data were collected with a questionnaire including the basic conditions, menopausal status, and frequency of musculoskeletal symptoms (rarely, occasionally or frequently) during the previous 2 weeks at the neck, lower back, knee and other sites. The prevalences of frequent symptoms were calculated for each site. Results A total of 743 women were enrolled in the study; 33.4% complained of frequent lower back pain, 31.0% of frequent knee pain, 29.7% of frequent neck pain, 25.6% of joint pain at other sites, 23.6% of joint stiffness and 21.1% of hand joint swelling. Postmenopausal women experienced a significantly higher prevalence of musculoskeletal symptoms compared with premenopausal women. There was a peak in prevalence of musculoskeletal symptoms at early postmenopause. The prevalences of neck pain and lower back pain were not associated with age, but did increase during the perimenopausal stage. The prevalences of knee pain, joint stiffness and hand joint swelling increased significantly with age. Higher body mass index (BMI) was related to increased prevalences of knee pain, joint stiffness and hand joint swelling. Logistic regression analysis showed odds ratios for knee pain, joint stiffness and hand joint swelling of 2.256, 1.865 and 1.955, respectively, in the obese women (BMI ≥ 28 kg/m2), compared with women with normal BMI (< 24 kg/m2). Conclusion Menopause is known to be a time of increased musculoskeletal symptoms, but the association of musculoskeletal symptoms with age and BMI also should be considered. [ABSTRACT FROM AUTHOR]

In this paper, the mixed alkalis, namely Ca(OH)2and NaOH, were used to disrupt soy protein. The structure characteristics and thermal properties of soy protein treated by Ca(OH)2and NaOH were studied by FT-IR and Differential scanning calorimetry (DSC). The results showed that soy-based adhesive by the mixed alkalis had better dry shear strength, wet shear strength, water resistance, and heat resistance than those of soy adhesive treated by NaOH alone. That was partly proved by results of FT-IR. DSC results indicated that the optimal weight ratio of mixed alkalis Ca(OH)2/NaOH was 2:1. [ABSTRACT FROM PUBLISHER]

A coupled system model of differential equations of pressure, temperature in shut-in procedures for high-temperature and high-pressure (HTHP) deviated gas wells was developed. Based on the Cullender-Smith method, we focus on the heat transmission in the stratum, and then calculate the temperature through differential equation. The basic data of X Well (HTHP well), 7,100 m deep, in Sichuan, China, is used for case history calculations. Gas pressure and temperature curve graphs along with the well are plotted at different times, intuitively reflecting flow law and the characteristics of the shut-in procedures. [ABSTRACT FROM AUTHOR]

In this article, a coupled system model of differential equations was derived in radial form to predict the pressure, temperature of formation, and temperature of wellbore in high-temperature–high-pressure gas wells. In the model, the thermal effect of formation was simplified as heat conduction, both the steady heat transmission model in the gas wellbore and the unsteady heat conduction model in the formation were considered, and the pressure effect due to variations in temperature was considered according to the gas equation of state, which links the temperature with the pressure. The finite difference method was used to simulate the solutions of the coupled models. The basic data for X Well (high-temperature–high-pressure gas well, 7,100 m deep) in China were used for case history calculations and a sensitivity analysis was performed for the models. Graphs of the curves for gas pressure and temperature along the depth of the well were plotted with different gradients, injection volumes, and the characteristic of heat transfer in the formation. The results provide technical reliability in well test design in high-temperature–high-pressure gas wells and the dynamic analysis of production. [ABSTRACT FROM PUBLISHER]

A coupled system model of partial differential equations concerning pressure, temperature, and velocity of gas–liquid–liquid three-phase transient flow in high-temperature, high-pressure (HTHP) wells is presented, according to mass, momentum, and energy balances as well as the stated equation of gas. A solution framework shared by the basic models is built, which makes it convenient to perform the solution process. The finite difference method was adopted to simulate the model. Based on the unified solution framework, the singular value decomposition (SVD) algorithm is employed to solve the large linear equations for the proposed model. The average value is adopted to solve the redundancy of model. The basic data for X Well (a 7,110-m-deep HTHP well in Sichuan, China) were used for case history calculations. Pressure, temperature, and velocity curve graphs along the depth of the well were plotted at different times, intuitively reflecting the flow law and the characteristics of heat transfer along a formation. The results can provide technical reliability in the process of designing well tests for HTHP gas wells and a dynamic analysis of production. [ABSTRACT FROM PUBLISHER]

The authors present a system model of partial differential equations concerning the variation of the pressure and temperature at different time and depth in high temperature-high pressure (HTHP) gas wells. Finite difference methods with Lax-Friedrichs scheme are improved to solve this set of conservation equations. The basic data of X Well (HTHP well), 7,100 m deep, located in Sichuan basin, Southwest China, is used for case history calculations. Gas pressures, temperature curve graphs along the depth of the well are plotted at different time. Comparing with the results without considering the influence of heat-transmission, the calculating results are more fitting to the values of real measurement. The comparison indicates that the new method is of high accuracy. [ABSTRACT FROM AUTHOR]

Ni0.5Co0.5Fe2O4(NCFO) nanoparticles were prepared by the chemical co-precipitation process using metal chloride, nitrate and acetate as precursor, after the precursors were annealed and then investigated in detail by employing X-ray diffraction (XRD), magnetic measurement and the bovine serum albumin (BSA) adsorption on the nanoparticles was analyzed by UV spectrophotometer at room temperature. XRD analysis indicates that all the as-prepared nanocrystals posses a pure cubic spinel structure. The saturation magnetization initially increases and then decreases with increasing annealing temperature, with a maximum value 67.19 emu/g at 950 °C. The coercivity also firstly increases and then decreases with increasing annealing temperature, with a maximum value of 828 Oe at 650°C. The as-prepared Ni0.5Co0.5Fe2O4nanoparticles exhibit a good adsorbing ability for BSA and the optimized adsorption is achieved for the Ni0.5Co0.5Fe2O4nanoparticles annealed at 750°C with grain size about 33.3 nm. [ABSTRACT FROM PUBLISHER]

Calcium is an important element in water bodies that plays a pivotal role in numerous biological processes; however, its effects on bloom-forming cyanobacteria have been studied only rarely. In the present study, the effects of calcium onMicrocystis aeruginosa, a major bloom-forming cyanobacterium, were investigated. Significant decreases in growth, chlorophyllaand maximum electron transport rate were shown when calcium was absent, while similar reductions in these parameters were also found at high concentrations of calcium (240 mg/l). The expression ofpsbA,grpEandrecAwas up-regulated significantly for 0 and 240 mg/l calcium treatments. The activity of catalase (CAT) also increased remarkably under these two treatments, suggesting thatMicrocystissuffered from stress under both calcium absence and under high calcium concentrations. Additionally, the polysaccharide synthesis gene,epsL, was up-regulated at high concentrations of calcium. These data suggest that calcium plays an important role in the growth ofMicrocystis, and that enhancement in polysaccharide synthesis in response to increases in calcium concentration might be responsible for bloom formation. [ABSTRACT FROM PUBLISHER]

The authors present a predicting model concerning pressure, temperature, density, and velocity of gas liquid two-phase transient flow in high-temperature–high-pressure wells, according to mass, momentum, and energy balances. The finite difference method is used to solve the model. A high-temperature–high-pressure gas well (6,115 m deep) in Sichuan Province of China is used to check the efficiency of the proposed model and the algorithms. [ABSTRACT FROM AUTHOR]

Presently, a coupled system model of differential equations is proposed to predict the dryness fraction of gas, the pressure, the temperature in the wellbore, and the temperature in the stratum. In this model, the authors consider the energy loss caused by the friction of the stem flow and the unsteady heat transmission, which caused the change of the temperature in the stratum, from the second interface to the stratum. Then the fourth-order Runge-Kutta method and the finite difference method are interactively applied to solve the model. Finally, a high-temperature–high-pressure gas well (7,100 m depth) in the Sichuan province of China is used to check the efficiency of the proposed model and the algorithms. [ABSTRACT FROM PUBLISHER]

A new diphenyl ether methyl 2-(2-formyl-3-hydroxy-5-methylphenoxy)-5-hydroxy-3-methoxybenzoate (3), together with four known compounds, asterric acid (1), methyl asterrate (2), 9(Z),12(Z)-nonadecadienoic acid (4) and orsellinic acid (5), were isolated from the Phoma sp. strain SHZK-2, which was isolated from a polluted environment in southern China. The structures of these compounds were determined by spectroscopic methods. Cytotoxicities of compounds against HEPG2 cell and Raji cell lines were preliminarily evaluated by the MTT method. [ABSTRACT FROM PUBLISHER]

The authors give a coupled system model of differential equations concerning dryness fraction of gas, pressure, and temperature in high temperature–high pressure steam injection wells according to mass, momentum, and energy balances. They present an algorithm solution model, along with the fourth-order Runge-Kutta method. The basic data from a high temperature–high pressure gas wells (7,100 m deep) in China were used for a case history calculation and a sensitivity analysis was also carried out. The gas flow law and the characteristic of heat transfer in formation were intuitively reflected in the algorithm and simulation. The results provide some technical insight in the process of designing well testing in high temperature–high pressure gas wells and the dynamic analysis of injection. [ABSTRACT FROM PUBLISHER]

We demonstrate the fabrication of metallic nanomesh with hexagonal array of circular holes by nanosphere lithography and measure the optical transmission spectrum of the nanomesh. The optical property of metallic nanomesh is theoretically investigated by the finite-difference time-domain method. The numerical simulation results indicate that the transmission properties of metallic nanomesh can be tuned by changing the hole diameter, period and film thickness. The optimized aluminum nanomesh shows enhanced broadband optical transmission of about 80%. This research provides a significant guidance for the design and fabrication of transparent metallic electrodes in optoelectronic devices. [ABSTRACT FROM AUTHOR]

Municipal solid waste used for landfill becomes stabilized, or aged, some years after placement, and can be safely excavated; the term ‘mineralized refuse’ is used in this study. The adsorptions of phosphorus, and the nitrification of the mineralized refuse and clay, were investigated by batch incubation. The variation of phosphorus adsorption in the mineralized refuse was fitted to the Freundlich adsorption isotherm equation, giving a maximum phosphorus adsorption capacity of 2310 mg kg−1. Based on the Langmuir isotherm equation, maximum phosphorus adsorption capacity was calculated to be 1976 mg kg−1, almost twice that of the clay. The equations for both the mineralized refuse and clay were fitted to zero-order kinetics (R 2>0.98, P<0.01, n=11), giving concentrations of phosphorus as phosphates less than 250 mg L−1. The K value for the mineralized refuse was about 3.5 times higher than for the clay. The production of nitrogen as nitrates in both the mineralized refuse and the clay after 120 h incubation yielded a first-order reaction kinetics value of 100 mg kg−1 NH –N from the initial concentration. The calculated net nitrification as nitrates for the mineralized refuse was 6.3 times higher than for the clay. Domestic wastewater was then treated in a mineralized refuse-based bioreactor for 30 days. The removal rates of CODcr, total nitrogen and total phosphorus were 73.77±8.10%, 61.01±6.75%, and 69.14±9.25%, respectively. Large accumulations of nitrates occurred in the mineralized refuse-based bioreactor. For the full-scale design, a high column of mineralized refuse is recommended for the denitrification. [ABSTRACT FROM PUBLISHER]

In this article, we present a coupled system model of differential equations concerning pressure, temperature, density, and velocity in high-temperature-high-pressure wells, according to mass, momentum, and energy balances. We present an algorithm solution model, along with the fourth-order Runge-Kutta method. The basic data of well X (high-temperature-high-pressure gas well), 7,100 m deep, in China, is used for case history calculations and a sensitivity analysis is made for the model. Gas pressure, temperature, velocity, and density curve graphs along the depth of the well are plotted with different outputs, intuitively reflecting the gas flow law and the characteristics of heat transfer along a formation. The results can provide technical reliability in the process of designing well tests in high-temperature-high-pressure gas wells and a dynamic analysis of production. [ABSTRACT FROM AUTHOR]