Encontrados 14 documentos, a visualizar página 1 de 2
Effect of temperature on the bioactive properties of bee pollen
Pascoal, A.; Rocha, J.F.; Choupina, Altino; Pereira, Ana Paula; Santos, Luís; Estevinho, Leticia M.Bee pollen is flower pollen collected by the honey bee, Apis mellifera, for the purpose of feeding its larvae in the early stages of development. It is recognized to be a valuable apitherapeutic product with potential for medical, health and nutritional applications. The objective of this work was to compares the effect of different storage conditions in the bioactive compounds and biological properties of bee ...
Sequential symbol synchronizers based on pulse comparison operating by positive...
Reis, A.D.; Rocha, J.F.; Gameiro, A.S.; Carvalho, J.P.This work presents the sequential symbol synchronizer based on pulse comparison by positive transitions at quarter rate (txp/4). Their performance is compared with a reference synchronizer by both transitions at the rate (tx). For the reference and proposed synchronizer we consider two versions which are the manual (m) and the automatic (a). The objective is to study the four synchronizers and evaluate their ou...
Prefilter bandwidth effects in data symbol phase synchronizers of open loop
Reis, A.D.; Carvalho, J.P.; Rocha, J.F.; Gameiro, A.S.This work studies the effects of the prefilter bandwidth on the open loop symbol synchronizers. We consider three different prefilter bandwidth, namely, B1=¥ ( infinite), B2=2.tx and B3=1.tx, where tx is the transmission rate. We consider also four open loop symbol synchronizers, namely, the tank (tank), the SAW (SAW), the monostable (mon), and the astable (ast). The objective is to study the prefilter bandwidt...
Prefilter bandwidth effects in sequential symbol synchronizers based on clock s...
Reis, A.D.; Rocha, J.F.; Gameiro, A.S.; Carvalho, J.P.This work studies the effects of the prefilter bandwidth in the sequential symbol synchronizers based on clock sampling by positive transitions. The prefilter bandwidth B is switched between three values, namely B1=∞, B2=2. tx and B3=1. tx, where tx is the bit rate. The synchronizer has two variants, one discrete and other continuous. Each variant has two versions, one manual and other automatic. The objective ...
Sequential symbol synchronizers based on pulse comparation at Half Rate
Reis, A.D.; Rocha, J.F.; Gameiro, A.S.; Carvalho, J.P.This work presents a synchronizer based on pulse comparation, between variable and fixed pulses. We consider four synchronizers, divided in two variants, one variant operate at the rate and the other at half rate. Each synchronizer variant has two versions which are the manual and the automatic. The objective is to study the synchronizers and evaluate the output jitter UIRMS (Unit Interval Root Mean Square) ver...
Indução da germinação in vitro de grãos de pólen de Musa velutina.
SANTOS, M. R. A. dos; FERREIRA, M. das G. R.; CORREIA, A. O.; ROCHA, J. F.O objetivo deste trabalho foi determinar os meios de cultura mais adequados para o estabelecimento e germinação in vitro de grãos de pólen de M. velutina, onsiderando a ausência de trabalhos na literatura científica abordando este tema. ; 2009
Sequential symbol synchronizers based on clock sampling by positive transitions
Reis, A.D.; Rocha, J.F.; Gameiro, A.S.; Carvalho, J.P.This work presents a sequential symbol synchronizer, that was discovered by us, and its functioning principle is based on the clock sampling by the input positive data transitions. This synchronizer has two topologies, namely the discrete and the continuous. Also, each topology has two versions which are the manual and the automatic. These synchronizers are very interesting, because the previous adjust of t...
Effects of the previous pulse shift and filter on the symbol synchronizer PLL
Reis, A.D.; Rocha, J.F.; Gameiro, A.S.; Carvalho, J.P.We will study the effects of the shift of the previous pulse temporal position (between P1 and P2) on the symbol synchronizers jitter behavior. Each pulse temporal position (P1 and P2), with the same previous filter, forms a group with four different carrier PLL (Phase Lock Loop) namely the analog, hybrid, combinational and sequential. The main objective is to study the synchronizers output jitter UIRMS (Unit I...
Carrier and symbol phase synchronizers
Reis, A.D.; Rocha, J.F.; Gameiro, A.S.; Carvalho, J.P.In this work, we will study the carrier phase Lock Loop (CPLL) when the input carrier changes its shape. The CPLL has four prototypes which are the analog, the hybrid, the combinational and the sequential. The input carrier can be a sinusoidal wave, a triangular wave or a rectangular wave. The objective is to study the four synchronizer types and to observe their jitter behaviors as function of the input carrie...
Deterministic and random phase synchronizers
Reis, A.D.; Rocha, J. F.; Gameiro, A.S.; Carvalho, J.P.This work study two groups of synchronizers, namely the Deterministic Phase Synchronizer and the Random Phase Synchronizer. The difference between them is only inside of the phase comparator. In the first group, the VCO (Voltage Controlled Oscillator) synchronizes with the input deterministic phase of an expected periodic transition. In the second group the VCO synchronizes with the input random phase of an une...
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