Data centers have become ubiquitous in the last few years in an attempt to keep pace with the processing and storage needs of the Internet and cloud computing. The steady growth in the heat densities of IT servers leads to a rise in the energy needed to cool them, and constitutes approximately 40% of the power consumed by data centers. However, many data centers feature redundant air conditioning systems that contribute to inefficient air distribution, which significantly increases energy consumption. This remains an insufficiently explored problem. In this paper, a typical, small data center with tiles for an air supply system with a raised floor is used. We use a fluent (Computational Fluid Dynamics, CFD) to simulate thermal distribution and airflow, and investigate the optimal conditions of air distribution to save energy. The effects of the airflow outlet angle along the tile, the cooling temperature and the rate of airflow on the beta index as well as the energy utilization index are discussed, and the optimal conditions are obtained. The reasonable airflow distribution achieved using 3D CFD calculations and the parameter settings provided in this paper can help reduce the energy consumption of data centers by improving the efficiency of the air conditioning.

The energy consumption of fast-growing data centers is drawing attentions from not only energy organizations and institutions all over the world, but also charity groups, such as Greenpeace, and research shows that the power consumption of air conditioning makes up a large proportion of the electricity cost in data centers. Therefore, more detailed investigations of air conditioning power consumption are warranted. Three types of airflow distributions with different aisle layouts (the open aisle, the closed cold aisle, and the closed hot aisle) were investigated with Computational Fluid Dynamics (CFD) methods in a typical data center of four rows of racks in this study. To evaluate the results of thermal and bypass phenomenon, the temperature increase index (β) and the energy utilization index (ηr) were used. The simulations show that there is a better trend of the β index and ηr index both closed cold aisle and closed hot aisle compared with free open aisle. Especially with high air flow rate, the β index decreases and the ηr index increases considerably. Moreover, the results prove the closed aisles (both closed cold aisle and closed hot aisle) can not only significantly improve the airflow distribution, but also reduce the mixture of cold and heat flow, and therefore improve energy efficiency. In addition, it proves the design of the closed aisles can meet the increasing density of installations and our simulation method could evaluate the cooling capacity easily.

Ontology makes knowledge sharing and analysis easier by making the meaning of data explicit. This paper presents a discussion on some of the current challenges for knowledge sharing in petrochemical domains and provides one approach to utilizing ontologies to solve some of the problems. With the WiKi and the experts of petrochemical's help, we abstract the classes and properties of the petrochemical domain and describe them with OWL. Protégé knowledge management platform are used to reason and verify them. Our ontology is a valuable resource with a potential to applications in a number of fields, specifically for digital data and information in computers, and semantic Web services.

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Abstract. Developing an interoperable system is one of today's challenging issues in ubiquitous enterprise systems. Initial Web Service-Oriented solutions have enabled the use and combination of distributed functional components within and across company boundaries, but they offer only syntactical description that failed to hold the promise of automatically interacting, dynamically composed web service. Semantic Web Services (SWSs) are an extension of Web Services, with an explicit representation of meanings, to improve their usage and ease scalability. In this paper, we present a Semantic Web Service-Oriented Architecture for enterprise in which data sources and services are made available through SWSs, described by ontologies, allowing interoperability as well as reasoning to create a comprehensive response adapted to user goals, and presenting a use case scenario in the context of an apparatus market, it can also be taken into e-govemment consideration.