EMI Suppression Characteristics of Pure and Impure Ni-Zn Ferrities and Mg-Zn Ferrities

Electromagnetic Interference (EMI) is a wave pollution, which interrupts the functioning of electronic circuits. Therefore, EMI wave absorbing materials are needed to suppress the wave pollution. One of the best solutions to overcome this problem is by using ferrites as EMI suppressors. This work is hoped to give a better understanding on how the purity of constituent oxides affects the suppression capability of ferrites. Moreover. it is also hoped to contribute in understanding how a good EMI suppressor can be made. A total of 1 2 toroidal samples with the composition of NixZnl-xFe204 and another 12 toroidal samples with the composition M&tZnl-xFe204 were prepared via the conventional ceramic processing method, where x = 0.1 , 0. 15, 0.2, 0.25, 0.3, 0.35. These samples were prepared to be ferrites with purities -99.99% and -;!J9. 1% which denoted pure and impure ferrites respectively. Subsequently, these samples were sintered in air at 1300°C. The measured parameters to study the magnetic properties were density, permeability, relative loss factor, impedance, resistivity, microstructure and XRD analysis. It was found that the overall magnetic properties for pure Ni-Zn Ferrites and Mg-Zn Ferrites were only slightly better than those of impure Ni-Zn ferrites and Mg-Zn Ferrites; the parameter values did not differ very much. Therefore, it is more economic if the impure materials are used for ferrite production instead of pure materials, which are more expensive

Changes In Mathematics Teachers' Questioning Techniques Through The Lesson Study Process

This study aimed to examine the changes in the mathematics teachers' questioning techniques through lesson study process. Two main research objectives were: i) to examine the changes in the mathematics teachers' questioning techniques in terms of probing, guiding and factual questioning when teaching mathematics; ii) to investigate the differences in the changes in questioning techniques among novice and experienced mathematics teachers. This study was conducted in Sarawak whereby ten (experienced and novice) teachers from two schools, namely School M (primary) and School P(secondary) underwent the lesson study process for fifteen months. Kajian ini bertujuan mengkaji perubahan teknik penyoalan guru matematik melalui proses lesson study. Dua objektif utama kajian ini ialah; i) menyiasat perubahan teknik penyoalan guru matematik dari segi mencungkil, membimbing dan penyoalan fakta; ii) mengkaji perbezaan perubahan teknik penyoalan dalam kalangan guru baharu dan guru berpengalaman. Kajian ini dilaksanakan di Sarawak, di mana sepuluh orang guru matematik (berpengalaman dan baharu) dari dua buah sekolah, Sekolah M (sekolah rendah) dan Sekolah P (sekolah menengah) telah melalui proses lesson study selama lima belas bulan

Is Malaysia exempted from impossible trinity: empirical evidence from 1991-2009

This paper examines Bank Negara Malaysia’s (BNM) monetary policy autonomy in 1991-2009, a period of volatile capital flows, during which BNM operated under several exchange regimes: managed floating; fixed exchange rates; and fixed exchange rates with selective capital controls. Using a modified version of the Brissimis, Gibson and Tsakalotos (2002) model, the paper’s empirical estimates show that the same-period offset coefficients are significantly less than unity under all regimes, indicating that the Malaysian central bank possesses some short-run control over monetary policy (even under fixed exchange rates). Although the long-run offset coefficient continues to be less than unity under managed floating, it is not significantly less than unity under fixed exchange rates. These results show that Malaysia is not exempted from the impossible trinity except in the very short-run. Perhaps one of the reasons Malaysia abandoned its US dollar exchange rate peg on 20 July 2005 to move back to managed floating is to increase its monetary policy independence. One implication of the Malaysian monetary policy experience is that managed floating with active sterilization may be a viable strategy for emerging market economies to deal with volatile capital flows.Offset Coefficient, Sterilization Coefficient, Monetary Autonomy, Impossible Trinity

On the Benefits of Network-Level Cooperation in Millimeter-Wave Communications

Relaying techniques for millimeter-wave wireless networks represent a powerful solution for improving the transmission performance. In this work, we quantify the benefits in terms of delay and throughput for a random-access multi-user millimeter-wave wireless network, assisted by a full-duplex network cooperative relay. The relay is equipped with a queue for which we analyze the performance characteristics (e.g., arrival rate, service rate, average size, and stability condition). Moreover, we study two possible transmission schemes: fully directional and broadcast. In the former, the source nodes transmit a packet either to the relay or to the destination by using narrow beams, whereas, in the latter, the nodes transmit to both the destination and the relay in the same timeslot by using a wider beam, but with lower beamforming gain. In our analysis, we also take into account the beam alignment phase that occurs every time a transmitter node changes the destination node. We show how the beam alignment duration, as well as position and number of transmitting nodes, significantly affect the network performance. Moreover, we illustrate the optimal transmission scheme (i.e., broadcast or fully directional) for several system parameters and show that a fully directional transmission is not always beneficial, but, in some scenarios, broadcasting and relaying can improve the performance in terms of throughput and delay.Comment: arXiv admin note: text overlap with arXiv:1804.0945

Abstrak Tesis-tesis ljazah Tinggi Pengajian llmu pendidikan, Universiti Sains Malaysia

Satu kelemahan datam sistem pendidikan kita adalah kekurangan kajian-kajian yang masalah menumpu ini,kepada pihak Jawatankuasa pendidikan tempatan. Penerbitan, Sebagai Puiat eenga.iia; satu langkah iimu[ecil pendidikan untutakan ,il.rgll"ri mula menerbitkan abstrak tesis-tesis rjazah ringgi yang telahiiLentanltan oleh calon-calonnya sebagai keperluan ljazah tersebut. Bagi jilid ini, kami akan menerbitkan abstrak tesis-tesis yang telah dibentangkan daripada tahun.1977 hingga 1980. Salinan tesis-tesis yang disenaraikan di bawah boleh dipinjam daripada perpustakaan, Universiti Sains Malaysi

The effect of network externalities on the perception of a new service offering mobile banking

This study extends previous research by determining if potential adopters' perception of innovation characteristics mediates the effects of network externalities towards their intention to use mobile banking. The study also explores the possible moderating effects of technology anxiety between network externalities, innovation characteristics and intention to use mobile bankin

Electrical, magnetoresistance and magnetotransport properties of Nd1−xSrxMnO3

The effects of Sr substitution on the electrical, magnetoresistance and magnetotransport properties of Nd1−xSrxMnO3 were studied. Nd1−xSrxMnO3 samples were prepared using the solid-state reaction method with x=0.12, 0.152, 0.22, 0.252 and 0.32. All samples showed an orthorhombic structure, and no impurities were detected when the samples were examined using the X-ray diffraction method. The grain size was between 10 μm and 16 μm for all samples. The sample with x=0.32 showed the smallest grain size and the lowest To value, where To reflects the MnOMn bond angle. As the Sr concentration increased, the grains grew into more pentagonal and hexagonal shapes, and the insulator–metal transition temperature, Tim, also increased from 131 K to 180 K. The exceptions were the samples with x=0.152 and 0.252, where charge ordering was found at 120 K. The samples with the most pentagonal and hexagonal shaped grains (x=0.32) had the highest Tim. The magnetoresistance (MR) values were found to increase with increasing magnetic field. The sample with x=0.32 showed the highest MR value (31.5%), the highest Tim, the smallest grain size (∼10 μm) and the least bending of the MnOMn bonding angle

Magnetotransport properties of La0.67Ca0.33MnO3 with different grain sizes

The magnetotransport and magnetoresistive (MR)properties of manganese-based La0.67Ca0.33MnO3 perovskite with different grain sizes are reported. The electrical resistivity was measured as a function of temperature in magnetic fields of 0.5 and 1 T. The insulator–metal transition temperature, TIM, shifted to a higher temperature with the application of the magnetic field. In zero field, TIM is almost constant (∼271 K) for all samples except for the sample with the largest grain size, where TIM = 265 K. The temperature dependence of resistivity was fitted with several equations in the metallic (ferromagnetic) region and the insulating (paramagnetic) region. The density of states at the Fermi level, N(EF), and the activation energy of electron hopping were estimated by fitting the resistivity versus temperature curves. The ρ–T 2 curves are nearly linear in the metallic regime, but the ρ–T 2.5 curves exhibit a deviation from linearity. The variable range hopping model and small polaron hopping model fit the data well in the high-temperature region,indicating the existence of the Jahn–Teller distortion that localizes the charge carriers. MR was found to increase with an increase in the magnetic field, an effect which is attributed to the intergrain spin tunneling effect

RNomic identification and evaluation of npcTB_6715, a nonprotein- coding RNA gene as a potential biomarker for the detection of Mycobacterium tuberculosis

Technological advances in RNA biology greatly improved transcriptome profiling during the last two decades. Besides the discovery of many small RNAs (sRNA) that are involved in the physiological and pathophysiological regulation of various cellular circuits, it becomes evident that the corresponding RNA genes might also serve as potential biomarkers to monitor the progression of disease and treatment. sRNA gene candidate npcTB_6715 was previously identified via experimental RNomic (unpublished data), and we report its application as potential biomarker for the detection of Mycobacterium tuberculosis (MTB) in patient samples. For proof of principle, we developed a multiplex PCR assay and report its validation with 500 clinical cultures, positive for Mycobacteria. The analysis revealed 98.9% sensitivity, 96.1% specificity, positive and negative predictive values of 98.6% and 96.8%, respectively. These results underscore the diagnostic value of the sRNA gene as diagnostic marker for the specific detection of MTB in clinical samples. Its successful application and the general ease of PCR-based detection compared to standard bacterial culture techniques might be the first step towards ‘point-of-care’ diagnostics of Mycobacteria. To the best of our knowledge, this is the first time for the design of diagnostic applications based on sRNA genes, in Mycobacteria