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In this paper, a compact Ultra-Wideband (UWB) antenna with a triple-band notch for wearable applications is designed and simulated for UWB applications with the operating frequency from 3.1 GHz to 10.6 GHz. The antenna can be used for UWB applications, while at the same time, is able to reject the narrowbands namely, Worldwide Interoperability for Microwave Access (WiMAX) (3.2 GHz to 3.6 GHz), C-band (3.7 GHz to 4.2 GHz) and Wireless Local Area Network (WLAN) (5.15 GHz to 5.35 GHz). Two slots are introduced on the radiating patch of the antenna to notch the three narrowbands, instead of three slots to notch each narrowband. The antenna is designed on a highly flexible polydimethylsiloxane (PDMS) substrate. The final outcomes indicate that the antenna can operate over the UWB frequency from 2.33 GHz to 11.30 GHz. The antenna is able to notch the WiMAX and C-band narrowbands with a frequency range from 3.08 GHz to 4.24 GHz and the WLAN band with a frequency range from 5.12 GHz to 5.40 GHz. The performance of the antenna in bending condition is also examined with the antenna bent over a varying diameter of vacuum cylinder starting from 50 mm, 80 mm and 100 mm. It is shown from the reflection coefficient of each diameter that the performance of the antenna is not affected by bending and thus, is particularly useful to be worn on body for wearable applications, other than its compact size of 19×14 mm2. The Specific Absorption Rate (SAR) results obtained shows that the antenna obeys the guidelines for 1 mW of input power. [ABSTRACT FROM AUTHOR]

The effects of different ratios of tire reclaimed rubber (TRR) and natural rubber (NR) on mechanical properties (tensile, tear, hardness and abrasion) were studied. The blends of TRR/NR (30/70, 50/50/ 70/30 and 80/20) were prepared by internal mixer and laboratory two-roll mill according to the standard. It is important to describe the mechanical properties of the samples as it provides the safety aspect of material specially those used in buildings, bridges and structural supports. The tensile strength, modulus and elongation at break of the blends were ascribed in tensile testing with the standard of ISO 37. The ability of reclaimed rubber blends to withstand force under tearing condition was measured by crescent tear test (ISO 34) and the resistance of material towards indentation force applied was tested by hardness (ISO 48). Abrasion resistance used to measure the volumetric loss of the blends when the samples is exposed to mechanical action (ISO 4649). The result showed that the addition of reclaimed rubber decreased the tensile strength and elongation at break. While the modulus at 100, hardness and abrasion properties increases with increasing reclaimed ratio. The ratio of 30/70 showed the best mechanical properties compared to the other blend ratios. [ABSTRACT FROM AUTHOR]

This research paper is about carbon fiber reinforced composite panels with novel bio-based epoxy derived from Malaysian crude Jatropha oil (Epoxidized Jatropha Oil) which is mixed with synthetic epoxy as matrix. Its manufacturability performances were then verified by tensile test, flexural test and burnt off test. Two composite panels (fiber carbon with 100 wt. % of synthetic epoxy and fiber carbon with 18 wt. % bio-epoxy blend with synthetic epoxy) were fabricated by vacuum assisted resin transfer moulding. Samples were cut according to respective ASTM dimensioning and were tested. It was found that the new composite panel performed well in manufacturability aspect with fiber volume fraction achieved was around 40 - 45%. Although its tensile and flexural performances are a bit lower but comparable, we could conclude that the novel bio-epoxy as matrix in fiber carbon reinforcement could be fabricated by using this process for further research. [ABSTRACT FROM AUTHOR]

Filters are key component of any communication system to control spectrum and suppress interferences. Designing a filter involves long process as well as good understanding of the basic hardware technology. Hence this paper introduces an automated design tool based on Matlab-GUI, called the FILTSoft (acronym for Filter Design Software) to ease the process. FILTSoft is a user friendly filter design tool to aid, guide and expedite calculations from lumped elements level to microstrip structure. Users just have to provide the required filter specifications as well as the material description. FILTSoft will calculate and display the lumped element details, the planar filter structure, and the expected filter's response. An example of a lowpass filter design was calculated using FILTSoft and the results were validated through prototype measurement for comparison purposes. [ABSTRACT FROM AUTHOR]

This paper presents the design and simulation of fast switching microwave rectifying circuit for ultra wideband patch antenna over a dual-frequency band (1.8 GHz for GSM and 2.4 GHz for ISM band). This band was chosen due to its high signal availability in the surrounding environment. New rectifying circuit topology with pair-matching trunks is designed using Advanced Design System (ADS) software. These trunks are interfaced with power divider to achieve good bandwidth, fast switching and high efficiency. The power divider acts as a good isolator between the trunks and its straightforward design structure makes it a good choice for a single feed UWB antenna. The simulated results demonstrate that the maximum output voltage is 2.13 V with an input power of -5 dBm. Moreover, the rectifier offers maximum efficiency of 86% for the input power of -5 dBm at given band, which could easily power up wireless sensor networks (WSN) and other small devices sufficiently. [ABSTRACT FROM AUTHOR]

A wearable antenna working in 2.4 GHz for Industrial, Scientific and Medical (ISM) radio bands is presented in this work. The proposed antenna is a rectangular textile antenna with a coplanar waveguide (CPW) feeding on a cotton jeans as the substrate material. The antenna has a compact size with dimensions of 30 × 30 mm2 which makes it an attractive solution in a wearable antenna construction. The linear characteristics of the antenna are investigated to evaluate the performance of the antenna. The simulation and measurements results are compared and they agree well with each other. [ABSTRACT FROM AUTHOR]

We have carried out a case study on Coronal Mass Ejections (CMEs) as a massive burst of solar wind and magnetic fields rising above the solar corona. During 15th April 2012, solar filament eruption was accompanied by intense CMEs. This explosion of CMEs observed by the Solar Dynamics Observatory with sunspot AR1458 is crackling with C-class solar flares. Solar flare type B3 and C2 were observed beginning 2241 UT and 0142 UT in the active region AR1458. In the present work, we focus in the range of the low frequency region from 150 MHz to 400 MHz. At preliminary stage, starting from 12.00 UT till 1.00 UT there is a strong signal which indicates a formation of burst. Type II burst originated from solar corona can be observed in the range of 150 MHz to 230 MHz. Instead of type II, a moving type IV and continuum type III burst can be detected at 150 MHz and lasting for 1 hours. This event is considered as second largest CMEs been detected since five (5) years. We can then conclude that currently, the Sun is in the phase of gradually increase to reach maximum 24th solar cycle. [ABSTRACT FROM AUTHOR]

The solar burst extinguish from the Sun's corona atmosphere and it dynamical structure of the magnetic field in radio wavelength are studied. Observation of solar radio burst with Compact Astronomical Low cost Low frequency Instrument for Spectroscopy and Transportable Observatory (CALLISTO) from ETH, Zurich in frequency range of 45 until 870 MHz. Observation done at Pusat Angkasa Negara, Banting, Selangor and successfully detected the solar burst type III on 9th March 2012 from 4:22:00 UT until 4:28:00 UT. The solar burst emission is associated with M6.3 solar flare which occurred at sunspot AR1429 at 03:58UT were observed by NOAA. Frequency ranges chosen as the best ranges for solar monitoring in Malaysia is 150 MHz until 400 MHz. The highest signal amplitude within this frequency ranges is 1.7619 dB at 153.188 MHz (Government Use) have potential to influence the detection of solar radio burst type III within 20 until 400 MHz. [ABSTRACT FROM AUTHOR]

This paper is devoted to solve the galactic rotation problem based on Modified Newtonian Dynamics (MOND). It addresses a new fundamental constant a0, called the acceleration constant, at which acceleration scale of Newton's second law fails to hold. It is an indication of a breakdown of classical Newtonian dynamics. In this respect, we choose the HI observations of a late type galaxy, ESO138-G014, to test the rotation curve within the MOND framework which leads to "MOND RC". We ask whether ESO138-G014 is compatible with MOND or dark matter is still favorable for the galactic rotation problem. [ABSTRACT FROM AUTHOR]

Observations of low frequency solar type III radio bursts associated with the ejection of plasma oscillations localized disturbance is due to excitation atoms in the plasma frequency incoherent radiations play a dominant role at the meter and decimeter wavelengths. Here, we report the results of the dynamical structure of solar flare type III that occurred on 9th March 2012 at National Space Centre, Sg Lang, Selangor, Malaysia by using the CALLISTO system. These bursts are associated with solar flare type M6 which suddenly ejected in the active region AR 1429 starting at 03:32 UT and ending at 05:00 UT with the peak at 04:12 UT. The observation showed an initial strong burst occurred due to strong signal at the beginning of the phase. We also found that both solar burst and flares tend to be a numerous on the same day and probability of chance coincidence is high. It is clearly seen that an impulsive lace burst was detected at 4:24 UT and it is more plausible that the energies are confined to the top of the loop when we compared with X-ray results. Associated with this event was type II with velocities 1285 km/s and type IV radio sweeps along with a full halo Coronal Mass Ejections (CMEs) first seen in SOHO/LASCO C2 imagery at 09/0426 Z. We concluded that the significance of study solar burst type III lies in the fact that the emission at decimetric wavelength comes from the role of magnetic field in active region that may provide the key to the energy release mechanism in a flare. [ABSTRACT FROM AUTHOR]

Apart of monitoring the Sun project, the Radio Frequency Interference (RFI) surveying in the region of (1-1200) MHz has been conducted. The main objective of this surveying is to test and qualify the potential of monitoring a continuous radio emission of Solar in Malaysia. This work is also an initiative of International Space Weather Initiative (ISWI) project where Malaysia is one of the country that participate a e-Callisto Spectrometer network in order to study the behavior of Solar radio burst in frequency of (45-800) MHz region which will be install in this October. Detail results will indicate the potential of monitoring a solar in Malaysia. [ABSTRACT FROM AUTHOR]

Radio astronomy is a new scientific research field in Southeast Asia. University Malaya is pioneering this field in this region with University Malaya Radio Telescope (UMRT-2), which is located on the department of physics, University of Malaya to detect neutral hydrogen emission line. In this paper, we observe Doppler shift of 1420 MHz for different radio sources to determine their dynamics. We also analyze radio spectra of different radio sources for these purposes including Coma Cluster roughly estimate the dark matter constant in it. We also investigated the observation time effort of Coma Cluster spectra detection we found the dark matter mass to be significantly too high, but we successfully concluded that longer observation time improves spectrum detection of weak radio sources. [ABSTRACT FROM AUTHOR]