Abstract: A smart grid is an emerging technology in the power delivery system which provides an intelligent, self-recovery and homeostatic grid in delivering power to the users. Smart grid communication network provides transmission capacity for information transformation within the connected nodes in the network, in favor of functional and operational needs. In the electric grids communication network delay is based on choosing the appropriate technology and the types of devices enforced. In distinction, the combination of IEEE 802.16 based WiMAX and IEEE 802.11 based WiFi technologies provides improved coverage and gives low delay performances to meet the smart grid needs. By incorporating this method in Wide Area Monitoring System (WAMS) and Advanced Metering Infrastructure (AMI) the performance of the smart grid will be considerably improved. This work deals with the implementation of WiMAX-WLAN integrated network architecture for WAMS and AMI in the smart grid.
Abstract: The aim of this descriptive study was to determine the perception of 21st century skills among nursing professors and nursing students at Boromarajonani College of Nursing, Chonburi. A total of 38 nursing professors and 75 second year nursing students took part in the study. Data were collected by 21st century skills questionnaires comprised of 63 items. Descriptive statistics were used to describe the findings. The results have shown that the overall mean scores of the perception of nursing professors on 21st century skills were at a high level. The highest mean scores were recorded for computing and ICT literacy, and career and leaning skills. The lowest mean scores were recorded for reading and writing and mathematics. The overall mean scores on perception of nursing students on 21st century skills were at a high level. The highest mean scores were recorded for computer and ICT literacy, for which the highest item mean scores were recorded for competency on computer programs. The lowest mean scores were recorded for the reading, writing, and mathematics components, in which the highest item mean score was reading Thai correctly, and the lowest item mean score was English reading and translate to other correctly. The findings from this study have shown that the perceptions of nursing professors were consistent with those of nursing students. Moreover, any activities aiming to raise capacity on English reading and translate information to others should be taken into the consideration.
Abstract: Implementation of advanced technologies requires
sophisticated instruments that deal with the operation, control,
restoration and protection of rapidly growing power system network
under normal and abnormal conditions. Presently, the applications of
Phasor Measurement Unit (PMU) are widely found in real time
operation, monitoring, controlling and analysis of power system
network as it eliminates the various limitations of supervisory control
and data acquisition system (SCADA) conventionally used in power
system. The use of PMU data is very rapidly increasing its
importance for online and offline analysis. Wide area measurement
system (WAMS) is developed as new technology by use of multiple
PMUs in power system. The present paper proposes a model of
Matlab based PMU using Discrete Fourier Transform (DFT)
algorithm and evaluation of its operation under different
contingencies. In this paper, PMU based two bus system having
WAMS network is presented as a case study.
Abstract: TiO2/Ag composite films were prepared by
incorporating Ag in the pores of mesoporous TiO2 films using a
photoreduction method. The Ag nanoparticle sizes were in a range of
3.66-38.56 nm. The TiO2/Ag composite films were characterized by
X-ray diffraction (XRD), scanning electron microscopy (SEM) and
transmission electron microscropy (TEM). The TiO2 films and
TiO2/Ag composite films were immersed in a 0.3 mM N719 dye
solution and characterized by UV-Vis spectrophotometer. The
TiO2/Ag/N719 composite film showed that an optimal size of Ag
nanoparticles was 19.12 nm and, hence, gave the maximum optical
absorption spectra. The improved absorption was due to surface
plasmon resonance induced by the Ag nanoparticles to enhance the
absorption coefficient of the dye.
Abstract: Low frequency power oscillations may be triggered
by many events in the system. Most oscillations are damped by the
system, but undamped oscillations can lead to system collapse.
Oscillations develop as a result of rotor acceleration/deceleration
following a change in active power transfer from a generator. Like
the operations limits, the monitoring of power system oscillating
modes is a relevant aspect of power system operation and control.
Unprevented low-frequency power swings can be cause of cascading
outages that can rapidly extend effect on wide region. On this regard,
a Wide Area Monitoring, Protection and Control Systems
(WAMPCS) help in detecting such phenomena and assess power
system dynamics security. The monitoring of power system
electromechanical oscillations is very important in the frame of
modern power system management and control. In first part, this
paper compares the different technique for identification of power
system oscillations. Second part analyzes possible identification
some power system dynamics behaviors Using Wide Area
Monitoring Systems (WAMS) based on Phasor Measurement Units
(PMUs) and wavelet technique.
Abstract: TiO2/MgO composite films were prepared by coating
the magnesium acetate solution in the pores of mesoporous TiO2
films using a dip coating method. Concentrations of magnesium
acetate solution were varied in a range of 1x10-4 – 1x10-1 M. The
TiO2/MgO composite films were characterized by scanning electron
microscopy (SEM), transmission electron microscropy (TEM),
electrochemical impedance spectroscopy(EIS) , transient voltage
decay and I-V test. The TiO2 films and TiO2/MgO composite films
were immersed in a 0.3 mM N719 dye solution. The Dye-sensitized
solar cells with the TiO2/MgO/N719 structure showed an optimal
concentration of magnesium acetate solution of 1x10-3 M resulting in
the MgO film estimated thickness of 0.0963 nm and giving the
maximum efficiency of 4.85%. The improved efficiency of dyesensitized
solar cell was due to the magnesium oxide film as the wide
band gap coating decays the electron back transfer to the triiodide
electrolyte and reduce charge recombination.