Avanti Publishers
Not a member yet
711 research outputs found
Sort by
Crab-Aquatic Plant System: A Model for Taking Ecological and Economical Care of the Lakes in Yellow River Delta, China
Get PDFThe lakes, including reservoirs and ponds in the Yellow River Delta, are characterized by many fragile ecosystems and low economic values. How to take into account both ecology restoration and the economic benefits of the lakes in this region is a complex problem. The Chinese mitten crab (Eriocheir sinensis)-aquatic plant system may have this potential. In this study, we planted aquatic plants, e.g., Elodea nuttallii, Hydrilla verticillate, and Vallisneria natans, with the crabs and investigated geochemical parameters in the ponds. The concentration of NH4+-N was lower than 0.5 mg/L, the pH of the breeding peiponds was 8.274-9.365, and the dissolved oxygen was 3.554-6.048mg/L, which was better than the class II environmental quality standards for surface water. The more extensive specifications ( > 150g/pcs) of the crab growth with the aquatic plants account for >35% of the total production. This model is significant to the ecological utilization of reservoirs in the Yellow River Delta but has low promotion. Therefore, some compulsory breeding policies and breeding standards must be proposed. It is the current ecological needs of the ecological protection Yellow River Delta
Recent Advances in Chitosan-based Nanocomposite Membrane Materials for Water Treatment
Get PDFIn recent years, research on chitosan (CS)-based nanocomposite membranes has made significant progress in the field of water treatment. This innovative membrane material incorporates a variety of excellent biological properties, including the biocompatibility and adsorption properties of the natural polymer chitosan (CS) and the introduction of nanotechnology. Furthermore, it enables the composite material to have excellent functional characteristics, such as higher water flux and selectivity. Furthermore, the enhancement of the structural and intrinsic properties of membrane materials will facilitate the attainment of further advancements in a multitude of performance characteristics, including stability, durability, and adsorption selectivity. Consequently, this field has become a promising area of research in water treatment technology, attracting extensive research and attention. However, the publication of a large number of related research reports in recent years, accompanied by numerous and complex performance optimization schemes and research ideas, has resulted in a paucity of articles that summarize these performance optimization strategies and research paths. Consequently, there are few meaningful references for subsequent research. In light of the aforementioned considerations, this paper will provide a comprehensive review of the most recent research advances in the field of water treatment, with a particular focus on the latest research strategies and frameworks for optimizing the performance of related materials. Furthermore, this paper will illustrate the innovative and beneficial applications of such materials from various vantage points, including their sources and preparation processes. It is anticipated that this paper will serve as a valuable source of inspiration for further research in this field
Utilizing Three Different Biochars for Attenuation of Toxic Acidic Mine Spoils Reflected by Lixiviate Quality Vis-a-Vis Phyto-Toxicity on Ocimum sanctum and Cassia angustifolia
Get PDFAcidic mine rejects of pyretic sulphur coal mines were treated with biochar prepared from different feedstocks (distilled waste of Cymbopogonflexuosus (lemongrass) and Cymbopogonwinterianus (Citronella) and the bark of Eucalyptuscitriodora. The quality of lixiviate collected at three intervals (0, 15, and 30 days) from each treated and untreated mine waste was examined, and holy basil (Ocimumsanctum) and East Indian senna (Cassiaangustifolia) bioassays were carried out. Results indicate that all three biochars improve the lixiviate quality, i.e., Enhanced the pH of lixiviate up to 3 units and reduces phytotoxicity. However, their magnitude of impact on lixiviates quality and phytotoxicity was different. The biochar prepared from the distilled waste of Cymbopogonflexuosus showed more promising results. The neutralizing capacity and dissolved organic carbon content were the significant factors for the discrimination of the amendments. The tolerance of O. sanctum and C. angustifolia was significantly different from each other for a particular treatment
Temporal Variation Analysis of Rice Yield in the Jiangsu Province, China: Application of Decision Support System for Agrotechnology Transfer Model
Get PDFThe accuracy of grain yield estimation is critical for national food security. Because of the comprehensive influence of spatial differentiation conditions, such as temperature, precipitation, soil, rice variety, and irrigation, yield estimation requires integrated modeling that is based on dynamic conditions. These dynamic conditions include geographical background, biological factors, and human impact. Most existing studies focus on the observation and analysis of external factors; only a few reports on yield simulations are coupled with nature, management, and crop growth mechanism. Our study incorporates the crop growth mechanism of rice, along with data of rice varieties, soil, meteorology, and field management, to determine the rice yield in Jiangsu province, China. In addition, we have used a decision support system for the agrotechnology transfer model, along with Coupled Model Intercomparison Project data and geographic information system technology. Our results showed that: (1) A calibrated variety genetic coefficient could simulate rice biomass value (flowering stage, maturity stage, and yield) reasonably. The values of NRMSE (Normalized Root Mean Square Error) between the simulated and measured values after parameter calibration are all less than 10%, the values of d(index of agreement) are all close to 1, the simulated value of yield is in good agreement with the measured value. (2) A linear correlation between the meteorological elements and yield was observed. The linear correlation had regional differences. Notably, an increase in precipitation was conducive to the increase in yield. Except at the Huaiyin site, the other sites showed that the temperature rise could potentially lead to reduced production. We found that an increase in solar radiation was unfavorable to the production of rice in the northern and western sites in the Jiangsu province, whereas it was conducive in the southern and eastern sites. (3) Our study predicted the rice yield from typical sites in the Jiangsu province from 2019 to 2060 in the wake of climate change while excluding the extreme effects of diseases, pests, typhoons, and floods. The order of average yield per unit area is as follows: Xinghua site (8212.76 kg/ha) > Huaiyin site (7912.70 kg/ha) > Gaoyou site (7440.98 kg/ha) > Gaochun site (7512.29 kg/ha) > Ganyu site (7460.88 kg/ha) > Yixing site (7167.00 kg/ha). Notably, the average yields from the Xinghua and Huaiyin sites were higher than that from the Jiangsu province (7617.77 kg/ha). The fluctuation of the yield per unit area at each site was generally consistent with the fluctuation in the overall yield, showing a downward trend and tends to be stable. The dispersion of yield per unit area indicates that Gaochun had the most stable yield per unit area followed by Xinghua, Ganyu, Yixing, Huaiyin, and Gaoyou. The yield per unit area of the Huaiyin and Gaoyou sites was unstable and portrayed the biggest fluctuations. Future studies need to focus on how to deal with spatial variation and carry out adaptive verification to make the simulation results applicable to more dimensions
Establishing Time-Depth Relationships Constrained by Modes of the Reservoir Architecture
Get PDFTime-depth relationships (TDRs) can connect seismic and wireline logs, both essential characterization data of reservoirs. The seismic well tie is always a complex work on account of the complicated reservoir structures. Since seismic and logging data are responses of reservoir architectures, the seismic well tie can be efficiently improved constrained by the reservoir architectures. This study adopts a clastic reservoir as the study area. Three architecture modes (i.e., normal cycle mode, inverse-normal cycle mode, and homogeneous-normal cycle mode) are summarized based on combinations of architecture elements. For the generation of the synthetic seismograms, optimized wavelets (i.e., wavelet A, wavelet B, and wavelet C) are suitable for the wells belonging to normal cycle mode, inverse-normal cycle mode, and homogeneous-normal cycle mode, respectively. Precise TDRs are established by matching the synthetics and seismic traces. Wells belong to the same architecture mode and have similar TDRs. The two-way travel time is shortest in the same depth interval of homogeneous-normal cycle mode compared to other architecture modes
A Novel Approach by Needles in the Payzone of Heterogeneous Tight Carbonate: A Case Study for Offshore Marginal Field
Get PDFThe new Fish-bones Completion & Stimulation approach by needles in the pay stack aims at addressing heterogeneous tight carbonate by increasing flow area in the lower permeable streaks, which is efficient as hundreds of tunnels drain connecting the borewell to the body of the reservoir to increase well productivity and oil recovery. The initial plan includes selecting the best ones fromย Stair step horizontal well, Dual Lateral well, five lateral fish-bone drilling, and horizontal drilling along with hydraulic fracture. Considering the lessons of failure to clean internal tubes, the modified 4-1/2โ Liner is installed in the lower two sub-layer by jetting subs combing with production subs for matrix acidizing in the upper one sub-layer as per modified Fish-bones Completion Design. In addition, special acid-releasing float shoes and new fishing baskets are applied to avoid those previous problems with this well technique. The candidate well shows good oil test and production, which improved by three times at 2000bbl/d with respect to the initial plan in the B field. This paper describes the technology background and characteristics, design factors, modified design, execution, well test, and lessons learned during implementation
Comparative Study on Interphase Force Model of Gas-Liquid Two-Phase Bubbly Flow Based on OpenFOAM
Get PDFIt is essential to choose an appropriate interphase force model when studying gas-liquid two-phase bubbly flow by numerical calculation. Because of the complexity of gas-liquid interaction, researchers have developed many models, while there is still a lack of corresponding guidelines when selecting the combination of interphase force models. In the present study, taking the DEDALE experimental condition as the research object, the parameter distribution characteristics of void fraction and gas-liquid two-phase velocity under the experimental condition are simulated, and the calculation results of different interphase force models are analyzed and compared with the experimental results. The effects of different interphase force models on the local parameter distribution characteristics of the two phases are analyzed and discussed, and the optimal model combination under this experimental condition is obtained
Vectorial Prabhakar Hardy Type Generalized Fractional Inequalities under Convexity
Get PDFWe present a detailed great variety of Hardy type fractional inequalities under convexity and Lp norm in the setting of generalized Prabhakar and Hilfer fractional calculi of left and right integrals and derivatives. The radial multivariate case of the above over a spherical shell is developed in detail to all directions. Many inequalities are of vectorial splitting rational Lp type or of separating rational Lp type, others involve ratios of functions and of fractional integral operators
Adaptive Dynamic Programming and Its Application to Economic Dispatch in Microgrid: A Brief Overview
Get PDFBoth adaptive dynamic programming and other intelligent algorithms can solve the economic dispatch problem in the microgrid. Adaptive dynamic programming can reduce the computational burden, which the intelligent algorithms suffer from, by using function approximation structure to approximate performance index function. In recent years, it has been also widely used in economic dispatch in the microgrid. In this article, we introduce some recent research trends within the field of adaptive dynamic programming based economic dispatch. Adaptive dynamic programming is firstly reviewed. Then, the current research works about adaptive dynamic programming based economic dispatch are summarized and compared. Furthermore, we point out some topics for future studies
Analysis of the Oscillations of Stratified Liquid with Elastic Ice
Get PDFWe study the problem of small motions of an ideal stratified liquid with a free surface totally covered by an elastic ice. The elastic ice is modeled by an elastic plate. We reduce the original initial boundary value problem to an equivalent Cauchy problem for a second-order differential equation in a Hilbert space. We obtain conditions under which there exists a strong (with respect to time) solution of the initial boundary value problem describing the evolution of the hydrodynamic system under consideration. We also study the spectrum of normal oscillations, the basic properties of the eigenfunctions