The dipping tube hydropneumatic tank is one of the most efficient equipments to prevent water hammer in water distribution and long distance transmission pipe systems. Due to its low costs and easy to maintain features, dipping tube hydropneumatic tank has many irreplaceable advantages, however it is difficult to determine the correct size and gas volume for real world engineering applications. This paper presents a robust method to solve the problems from theory and application. Based on the Method of Characteristics (MOC) equations, this paper derives the equations for modeling dipping tube hydropneumatic tanks in water distribution systems to prevent water hammer. The equations include MOC, differential orifice head loss equation, gas law, air mass, air velocity and etc. The IBMs scientific subroutine package (SSP) is applied to solve the equations by deriving to the form of X=f (X). The method has been integrated into HAMMER. This paper also presents an example to illustrate the methods of determining the tank size, and the comparison results with sealed hydropneumatic tank and surge tank equipment.
With the growing penetration of distributed energy resources on the network the operation regime has been changed from passive to active which brings a number of impacts to the network including voltage control, power flow management and protection issues etc. As one of the dominant impact, the voltage control strategy has become a key enabling technology for the deployment of renewable energy systems. This paper provides a comprehensive review on voltage control for active distribution networks, the efficiency and practicability have been studied in details.
The system in the paper based on Matlab platform. With the aid of image processing toolbox of soil image analysis and processing, the soil grain size distribution and its inclination angle can be got. It overcomes the insufficiency of the existing image edge extraction method, and proposes a new type of detection method, in order that the region of interest can be more accurately extract. The system is helpful to predict the possibility of the regional landslides.
Many machine learning approaches in the field of Artificial Intelligence (AI) have been developed. Most of them rely on using large data sets to build up knowledge. However, the traffic system usually has only few data. In this article, the so-called adaptive neural fuzzy inference systems (ANFIS) is employed to predict the traffic time-series with few data, including flow, speed and occupancy
As modern materials and techniques are widely used in the countryside, the living environment which is peculiar to traditional vernacular buildings is damaged. Then the buildings and the construction technology are at risk of elimination and extinction. This paper takes seaweed house as typical example, attempting to explore how the vernacular buildings develop in an original, plain and ecological way.
Ontology and semantic are very popular in Web, and the construction of Web dynamic ontology has been the problem urgent to be solved. Firstly, the basic framework for constructing Web dynamic ontology is shown. Next, the concept lattice is introduced, based on which the novel method of building Web dynamic ontology is given. It includes constructing the initial ontology, extracting web knowledge, generating the formal contexts, merging formal context, merging concept lattices with ontology-based similarity calculation, transforming the concept lattice to the ontology. At last, the stock information system is employed to verify the methods proposed. The results showed the stock ontology could be dynamically updated with the change from the Web, and we can get new inferred knowledge from the updated stock ontology by Racer; the method proposed is valid and feasible.
Drought is a world-spread problem seriously influencing grain production and quality, the loss of which is the total for other natural disasters, with increasing global climate change making the situation more serious. Rice is the staple food for more than 23% of world population, so rice anti-drought physiology study is of importance to rice production and biological breeding for the sake of coping with abiotic and biotic conditions. Much research is involved in this hot topic, but the pace of progress is not so large because of drought resistance being a multiple-gene-control quantitative character. On the other hand, stress adaptive mechanisms are quite different, with stress degree, time course, materials, soil quality status and experimental plots, thus increasing the complexity of the issue in question. Additionally, a little study is related to weedy rice.In order to investigate the effects of drought stress on germination and early seedling growth of weedy rice (Oryza sativa f. spontanea L.) and cultivated rice (Oryza sativa L.), polyethyleneglycol-6000 (PEG-6000) are used to generate -1.33MPa and 0MPa water stress in a laboratory condition (28±3°C). Complete randomized design with three replications is used in the study. After 10 days of germination, shoot length, the longest root length, root fresh weight, root dry weight, shoot fresh weight, shoot dry weight and root numbers are measured; germination percentage, and root to shoot ratio are calculated. Germination index (GI), shoot length stress index (SLSI), root length stress index (RLSI) and dry matter stress index (DMSI) are used to evaluate the response of different genotypes to PEG-induced water stress. Results of ANOVA analysis show that responses of weedy rice accessions and cultivated rice varieties to water stress are significant different, demonstrating the germplasm of weedy rice and cultivated rice are diverse which enables us to screen the germplasm tolerant to drought stress.
In Chongqing Three Gorges Reservoir Area (TGRAC), the natural conditions of production of Tung oil tree (Vernicia fordii) are advantageous. It has an abundant cultivated varieties resource, a long history of cultivation, and is World-renowned by its excellent quality of oil. After 1990s, Tung oil production is gradually shrinking, a large number of Tung oil trees resources had been destroyed, Due to the excessive use of fossil fuels in today's world, however, there have been the deterioration of the environment and energy crisis. So clean and green biomass energy sources are favored. This paper introduces the resource status and distribution area of Tung oil trees, analyzes the planting advantages and development prospects of Tung oil trees, and provides suggestion on the development of the Tung oil trees industry in the TGRAC.
According to the importance of the management for the science research institution in a university, the management information system of resource-oriented science research institution based on REST and AJAX was developed. Firstly, the function module of the system was given from practice. Then, the system architecture was given, and the design was proposed in detail, including the resource, the database and the class. Finally, the interfaces of the client in the achieved system were given, and the implementation showed that the solution of the system is valid and feasible.
Today, load characteristic analysis plays a vital role in network planning, operation and control. In particular, with massive demand side participation activities on the network, the characteristics of individual load determines the way of the active load management as well as the network pricing strategies. In this paper, the load characteristics are analyzed utilizing clustering techniques for a tropical isle with massive temperature sensitive loads. Through deeply mining of real data, the features of individual loads were observed to define the way of load participation.
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