Tekhné

12

Authors: Juan Goncalves, José Cotúa

Taking into consideration the necessity of remote processes management, this work presents an alternative monitoring and remote control system handled through massive use terminal equipments, as mobile phone and PC. This system can collect data from a far away physical process and take action on it in order to have the best remote process development through a web or wap page, depending on the terminal equipment. Using a microcontroller PIC18F4620, which can connects to the Internet using an Ethernet controller ENC28J60 supported by the MODBUS/TCP/IP stack, the Remote Telecontrol Unit has been created to be able to transmit all signals measurements from its interfaces to the Control Center Unit (CCU) data base. This equipment can either, communicate to the RTU or, be in charge of show saved values in its data base by web and wap pages. This same CCU, through web and wap applications, can also control the signals on the remote microcontroller pins. Finally, taking advantage of the great TCP/IP networks development, the RTU can be placed anywhere, where can be connected by an Ethernet RJ-45 interface to the Internet, and can be controlled from any place using an Internet connected PC or by a mobile phone under a network which supports wap

15

Authors: Cristián Cárdenas-Lailhacar, Vitelio E. Silva

Efficiency in motors has always played an important role in energy analysis in industry. Their importance is dramatic as motors account for about 50% to 60% of the energy used by industries. Particularly considering that energy costs generate a high impact over profitability in the industry sector. However, several studies have demonstrated how different can be the approach and subsequently the results from energy analysis, depending on how the efficiency motor is estimated. Actually, some changes have been identified in European standards (IEC 34-2) in order to improve the accuracy level obtained, requested and finally offered to the industry within efficiencies motor standards. Meanwhile, other studies have demonstrated the convenience of American standards (IEEE 112 and National Electric Manufacturers Association - NEMA) related to actual values of efficiencies, and compared with other standards available and generally accepted world-wide. Due to the high relevance of motor efficiency estimation over energy analysis, this work includes a new pragmatic approach, based on previous analysis related to the most accurate standard, generally accepted in the industry. It develops a way of estimating the efficiency of the motor according to its size (in hp) and its rpm. The procedure shows very accurate efficiency value for that motor (under certain standard conditions), required for motors energy management analysis. One of the main advantages offered by this approach is that it gives a reliable and quick estimation of motors efficiencies, available for the analysts with little data gathering. Most importantly, the results are in excellent agreement with American standards references. In addition, we present with our findings, and using extrapolation techniques, 3-dimensional efficiencies surfaces to show and justify, the best working conditions. Finally, a brief background and an example of energy analysis for a motor replacement is presented, based on the cost savings obtained due to a difference in the motors efficiency level in its design.

19

Authors: Franklin Planchart

At the present time the debate on the politic control of the numbering resources is a daily fact. This control goes in function of number IP and the names of domain. Protocols like the ENUM (tElectronic NUmber Mapping, RFC 2916), whose objective is to separate the telephone’s structure scheme of the present control by means of integration of networks IP and the PSTN (Public Switching Telephone Network) based on format of numbering E.164, could not have been implemented due to restriction to grant one root of level zero by part of ICANN (Internet Corporation Assigned of Names and Numbers) for the creation of the e164.arpa domain, parallel to in-adr.arpa (root of the present dominion). The solution raised in this document has been to recommend the creation of the plan of world-wide numeration based on IPv6 that it introduces the concept of nationality in the IPv6 format. Also has considered the creation of one system of names based on code country that it allows to address and to consult the DNS (Domain Name System) of the countries (at level of telephone’s services) without having to go for a root system controlled by one nation in individual way. In fact the proposal in this document is a division of the DNS. This alternative has considered the integration of ENUM protocol, the portability and mobility through the connection of the PSTN with the Network IPv6. The exposition of the introduction of IPv6 occurs as a solution to be able to introduce UMTS (Universal Mobile Telecomunications System) in massive form and to get the maximum benefit to the platform from xDSL (x Digital Subscriber Line). The conclusion of this proposal is to eliminate the NAT (Network Address Translation) in totally way through the substitution of the plan of present numeration, which is based on IPv4.

19

Authors: Karly C. Guzmán Peña, Neiris G. Rodríguez, Mario Paparoni

This work is a compilation of different slab design methods and it have the intention to bring to the readers a useful tool that could help them to choose the most appropriate design method. When a slab design take place, keeping in mind the particular conditions of every situation. The study of this different slabs calculation methods consists of the analysis of its precedents, uses, advantages and disadvantages, applied to a rectangular simply supported slab calculation; who is designed by the methods of: Break Lines, Arbitrary Loads, Marcus and Timoshenko, and then compare the differences of values and results between them. After the compilation of the input data and designs by the methods previously mentioned and making a exhaustive analysis, we show a series of useful diagnoses. It is our desire that this work facilitates the choice of the most suitable slab design method, in agreement with the requirements of the study, because it is not necessary to use so rigorous and exact treatments, when with much simpler methods it is possible to obtain satisfactory results, Althought so the slab resists the design solicitations.