A Method of Forming a Broad-Band Microwave Frequency Spectrum

A hybrid fractal antenna inspired from sri yantra geometry covering multiple bands in the microwave frequency spectrum is presented in this paper with a reduced size of 45mm x 30mm x 1.6mm. The presented design aims at a multiband antenna with a polygon slots in- scribed in a circular patch with defected ground structure and the effect of Sri Yantra fractal iterations on the antenna characteristics are also studied. The gains achieved at respective bands for Sri Yantra geometry are 4.61dB at 4.04GHz, 2.71dB at 4.94GHz, 4.77dB at 5.88GHz, 3.41dB at 6.60GHz, 5.12dB at 7.24GHz, 3.11dB at 8.88GHz and 3.47dB at 10.92GHz.

Download Full-text

Early Result for Microtremor Characteristic Observation in Merapi and Merbabu

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/873/1/012077 ◽

2021 ◽

Vol 873 (1) ◽

pp. 012077

Author(s):

E. Fernanda ◽

A. Bilqis ◽

L. Julio ◽

K. Nursal ◽

Y. H. Christ ◽

...

Keyword(s):

Frequency Spectrum ◽

Broad Band ◽

Vertical Component ◽

Low Frequency ◽

Eurasian Plate ◽

Merapi Volcano ◽

Hydrocarbon Reservoir ◽

Central Java ◽

Recording Station ◽

Passive Seismic

Abstract The arc magmatism and volcanic activity in Java are dominated by the subducting plate of Indo-Australian into the Eurasian plate. Merapi volcano is located in Central Java and known as one of the most active volcanoes in the world. Several studies have tried to estimate the magma reservoir zone in Mt. Merapi and suggested multiple layers of reservoirs with the shallow one at 1-2 km and a deeper at 6 -9 km or 15 km. The Low-Frequency Passive Seismic is one method to analyze the frequency spectrum below the recording station. Previous related studies show a promising a relation between hydrocarbon reservoir and higher amplitude at vertical component at a frequency between 0.1 – 6 Hz. An observation at the volcano sites have also been reported to display a different spectrum amplitude at the vertical component. This study exploited the same method in LFPS to analyze the frequency spectrum at Mt. Merapi and Mt. Merbabu. We use seismic data from the DOMERAPI temporary seismic network installed in the neighborhood of Merapi and Merbabu volcano. We analyze 53 broad-band seismometers data from October 2013 to mid-April 2015. We also add several stations from MERAMEX network instruments to compare spectrum analysis outside the Merapi and Merbabu volcano. We also removed some tele-seismic and regional events from the data to better analyze the LFPS signal. We have seen a higher amplitude in vertical component near Mt. Merapi and will proceed to analyze all stations.

Download Full-text

Some Effects of Noise on the Speaking Behavior of Stutterers

Journal of Speech and Hearing Research ◽

10.1044/jshr.1704.714 ◽

1974 ◽

Vol 17 (4) ◽

pp. 714-723 ◽

Cited By ~ 24

Author(s):

Edward G. Conture

Keyword(s):

Frequency Spectrum ◽

Broad Band ◽

Cutoff Frequency ◽

Reading Rate ◽

Read Aloud ◽

Noise Condition ◽

Low Pass ◽

Frequency Reading ◽

High Pass ◽

Different Levels

The purpose of the present research was to determine the influence of the loudness and spectrum of noise stimuli on stuttering frequency, reading rate, and vocal level. During each of six noise conditions and one non-noise condition, nine stutterers continuously read aloud prose passages during four successive five-minute periods. Low-pass (500-Hz cutoff frequency), high-pass (500-Hz cutoff frequency), and broad-band noise, psychophysically equated for loudness at two different levels, was presented during the third period of the six noise conditions. Stuttering frequency, reading rate, and vocal level were measured for the second and third periods of all conditions. The stutterers increased their vocal level while decreasing their stuttering frequency as a result of the loudness rather than the frequency spectrum of the noise. Reading rate was not significantly influenced by changes in the loudness or frequency spectrum of the noise. These results do not support the findings of others that low-pass noise decreases stuttering more than does high-pass noise.

Download Full-text