Three comparisons of ac–dc voltage transfer difference held from January to December 2004 are reported. Six NMIs in the SIM region took part: NRC (Canada), NIST (United States of America), CENAM (Mexico), INTI (Argentina), UTE (Uruguay) and INMETRO (Brazil).The comparisons were proposed to assess the measurement capabilities in ac–dc voltage transfer difference of the NMIs in the SIM region. The test points were selected to link the results with the equivalent CCEM Key Comparisons, through three NMIs participating in both SIM and CCEM key comparisons. Additionally, a SIM.EM-Supplementary comparison was proposed, in support of the SIM NMIs' power/energy meter calibration capabilities. One technical protocol and one travelling standard were used, to economize on time and resources.The report shows the degree of equivalence in the SIM region and also the degree of equivalence with the corresponding CCEM reference value. The results of all participants support the values and uncertainties of the applicable CMC entries for ac–dc voltage transfer difference in the Key Comparison Database held at the BIPM.Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Under the auspices of the Committee Consultative of Electromagnetism, CCEM, the SIM Electromagnetic Working Group carried out a key comparison of power standards at 50/60 Hz. This key comparison, identified as SIM.EM-K5, aims to provide a link to various NMIs in the SIM region to the CCEM-K5 key comparison on 50/60 Hz power completed in 2001 and piloted by NIST. Measurements in the SIM.EM-K5 comparison were carried out from May 2010 to March 2012, including testing points of active and reactive power. CENAM was the pilot laboratory. Differences between the measurement results of the participating laboratories and the reference value of this key comparison, calculated at each of all the testing points, show a good infrastructure of national standards of measurement of electric power in the SIM region. Based on previous work, a link has been estimated between the results of the CCEM-K5 and the SIM.EM-K5 key comparisons, whose results were reported in 2002 and 2014, respectively. From the link it is shown that the measurement results of SIM.EM-K5 comparison are well supported. The SIM.EM-K5 comparison is a rewording exercise of comparison of the national standards of measurement as recommended by the CIPM. The participating laboratories are fully recommended for their enthusiastic participation in the comparison. Their individual efforts to maintain the national standards of power measurement are acknowledged.

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This work presents a preliminary study of the Brazilian Equatorial Atmosphere Research Satellite (EQUARS) attitude control subsystem (ACS). The satellite ACS requirements are dictated by the scientific experiments and the power supply needs. The scientific experiments require a three-axis attitude control subsystem in order to accomplish their pointing goals. In this paper the attitude control studies are conducted on the basis of the Linear Quadratic Gaussian regulator approach (LQG) to evaluate the control performance and the control effort during the satellite normal operational mode. The results indicate that the necessary actuators (reaction wheels) are available commercially on the shelf. The MATLAB ®

At CENAM Mexico, new ac-dc voltage m s f e r standards have been developed for the voltage range from 2 mV to IO00 V in close cooperation with NMi-VSL, The Netherlands and PTB, Germany. CENAM has improved its measurement techniques and facilities and has participated in international comparisons with F ' T B , NIST and NRC.