Cerne e alburno em eucaliptos: influência da espécie e da idade nas propriedades tecnológicas

Pós-graduação em Ciência Florestal - FCA

Anther wall development, microsporogenesis, and microgametogenesis in abolboda and orectanthe: contributions to the embryology of xyridaceae (poales)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Recovery Tests of an Hybrid Current Limiter Composed of a SFCL in Parallel to an Air-Core Power Reactor

The resistive-type superconducting fault current limiters (RSFCL) prototypes using YBCO-coated conductors have shown current limitation for medium voltage class applications for acting time up to 80 ms. By connecting an air-core reactor in parallel with the RSFCL, thus making an hybrid current limiter, one can extend the acting time for up to 1 s. In this work, we report the performance of a hybrid current limiter subjected to an AC peak fault current of 2 kA during 1 s for which within the first 80 ms the SFCL limits the current concurrently with the air-core reactor, and for the remaining 920 ms, only the air-core reactor limits the current. In order to evaluate the actual conditions for subsequent reconnection of RSFCL to the power grid, the hybrid fault current limiter was tested varying the time interval for recovery from 900 ms and 1.2 s, followed again by the concurrent operation of the hybrid limiter during 1 s (SFCL during 80 ms). From this evaluation test, the recovery time can be measured and compared using the voltage peak generated in superconducting module from the first and second fault test. The recovery time was also determined through the pulsed current method (PCM) on short-length sample test. The results showed that the fault current was limited from 1.9 kA down to 514 A after 1 cycle of 60 Hz frequency, with recovery time lower than 1.2 s for two subsequent fault current tests.

Integration of wireless sensor networks to the internet of things using a 6LoWPAN Gateway

The Internet of Things is a new paradigm where smart embedded devices and systems are connected to the Internet. In this context, Wireless Sensor Networks (WSN) are becoming an important alternative for sensing and actuating critical applications like industrial automation, remote patient monitoring and domotics. The IEEE 802.15.4 protocol has been adopted as a standard for WSN and the 6LoWPAN protocol has been proposed to overcome the challenges of integrating WSN and Internet protocols. In this paper, the mechanisms of header compression and fragmentation of IPv6 datagrams proposed in the 6LoWPAN standard were evaluated through field experiments using a gateway prototype and IEEE 802.15.4 nodes.

Evaluation of longitudinal modulus of elasticity in wood species for structural application

1024x768 This research aimed to investigate possible differences in values of longitudinal modulus of elasticity for wood species usually employed for structural purposes, as Castanheira (Bertholletia excelsa), Cambará (Erisma uncinatum), Cumaru (Dipteryx odorata), Jatobá (Hymenaea stilbocarpa), Garapa (Apuleia leiocarpa) and Peroba Rosa (Aspidosperma polyneuron), obtained from compression and tension parallel to grain, and static bending tests. Recommendations of the Brazilian standard ABNT NBR 7190:1997, Annex B, were followed. Statistical analysis results for the cited properties, had equivalent averages for the six wood species analyzed. This confirms that any of the three tests can be used to obtain the longitudinal elastic modulus and which could avoid the necessity of evaluating stiffness values for wood by more than one kind of mechanical test. Normal 0 21 false false false PT-BR X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabela normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

Sinais digitais de um durômetro portátil para a estimativa de propriedades de madeiras para dormentes

Pós-graduação em Agronomia (Energia na Agricultura) - FCA