In the present experimental study, a photovoltaic (PV)-powered system in continuous current (4 kW) for the pumping of water in an isolated, rural agricultural zone in Arequipa—Peru was analyzed. A meteorological station was installed in the studied zone, measuring solar radiation, temperature, relative humidity, and wind speed. The electrical and hydraulic parameters of the solar-pumping system (i.e., electric current, voltage, mass flow, and hydraulic pressure) were measured in order to evaluate the efficiency of the energy transformation processes. The results indicate that, during the year of 2017, the PV pumping system in direct current (DC) functions from 07 h 30 min to 15 h 30 min, during an average of 8 h a day. The PV array, hydraulic, and global efficiencies were evaluated. This allows for the interpretation of efficiency independent of solar irradiance. The efficiency of the PV array and global efficiency remained constant (11.5% f and 8.5%, respectively). The functioning interval of the PV array ranges from 880 W up to 3400 W, making evident the versatility of the system of generation and consumption in DC, which is able to function since solar irradiance is at least 200 W/m2, corresponding to 880 W of PV array power, 27 m of total dynamic head (TDH) and 2 kg/s of mass flow, and 70% hydraulic efficiency. With greater mass flows (6.3 kg/s), the PV array power was 3256 W with a hydraulic efficiency of 55%, a TDH of 30 m, and a peak solar irradiance of 1190 W/m2. When the whole system functions in DC, the efficiencies are superior to those of systems, which operate with DC/alternating current (AC) current inverters.

This paper describes a proposal for developing an architecture for Educational Cloud based on OpenStack framework, Service Composition techniques and Semantic Web to create virtualized environments with specific features for teaching and researching environments, through the study of recent patents correlated to this system. The creation and management of the architecture and its virtualized environment are conducted through a system of service composition. Services are made available as a catalogue and their access is limited by the user’s profile type (student, teacher, or researcher). The results shown in this article are limited to the presentation and description of the system logic architecture and modeling.

Semantic web research aims to provide mechanisms to combine several web services to offer a new value-added service that satisfies the user's request. A number of methods and tools have been proposed for this purpose. However, none of these approaches offers a complete solution from the standpoint of a decoupled, inter-organisational, domain-independent and ready for use by end users who do not have an in-depth technical knowledge. To overcome these limitations, this paper provides a loosely coupled architecture to develop applications based on web services composition, in which architectural modules can be integrated in different ways, ranging from inter-organisational sources, which support different levels of automation and composition methods, to diverse application domains. We described the input and output requirements for each module and implemented the following decoupled modules: interface (for non-technical users), translator (using the ANTLR tool), composer (using a hierarchical planner) and executor (based on workflows).

Service Oriented Computing (SOC) is a computing paradigm for the agile development of software based on the orchestration of loosely-coupled services. Services perform functions from the solution of simple atomic requests to execution of complex business processes. Nowadays, new services are created from the manual composition of basic Web Services. It is an arduous and susceptible to errors task. To avoid this problem, it is necessary the existence of discovery and automatic composition mechanisms. This paper presents the specification of a architecture and implementation of a prototype for the automatic composition of Web Services using Artificial Intelligence planning techniques and the WSMO ontological model. Moreover, the paper contains a discussion about design and implementation choices and further improvements.