Characteristics of Mineral Oil-based Nanofluids for Power Transformer Application

Trends in the field of nanomaterial-based transformer oil show most of the conducted works have focused only on the transformer oil-based nanofluids but limited studies on the stability of transformer oil-based nanofluids. Since mineral oil-based nanofluids still can produce the sedimentation, thus the cold-atmospheric pressure plasma method is proposed to functionally modify the Silicon Dioxide (SiO2) nanofiller in order to enhance the electrical properties of the mineral oil-based nanofluids. The AC breakdown strength oil samples before and after modification were measured. It was found that the plasma treated nanofluids have higher AC breakdown voltage compared to pure oil and untreated nanofluids. Also, Fourier Transform Infrared (FTIR) Spectroscopy has been used in this study to analyse the physical changes of oil samples. It is envisaged that the added silica nanofiller has significant effect on electrical properties of the transformer oil-based nanofluids which would enable to the development of an improved class of liquid dielectric for the application of power transformer

Fractal Characteristic of Electrical Trees Grown in Silicone Rubber under Environmental Stress

One of the degradations of insulation is in the form of electrical treeing in which classified as a pre-breakdown phenomenon of electrical insulation. The electrical tree is commonly forming in the shape of tree-like or root-like which may have fractal structures. Due to this fractal structure, electrical treeing formation and patterns are analysed via fractal dimension and lacunarity to study the self-similarity patterns of electrical treeing. Many types of research have been conducted to study the fractal dimension and lacunarity of electrical treeing to fully understand the electrical tree mechanism and characteristics. However, fractal and lacunarity structures o

Meningkatkan Motivasi dan Prestasi Belajar Matematika Siswa melalui Pemberian Pekerjaan Rumah Disertai Umpan Balik

Increasing Motivation and Achievement of Student Learning through Homework Accompanied Feedback. This research to know how big improvement of motivation and achievement of student in studying math through learning process in form of giving homework accompanied feedback in SMPN 1 Tujuh Belas school years 2011/2012. Research method which is use in classroom action researchconsist of two cycles. Research subject is eighth grade students of SMPN 1 Tujuh Belas school years 2011/2012. Based on data analysis obtained result of research :(1) Applying study through homework accompanied feedback can increase students motivation in learning of eighth grade students of SMPN 1 Tujuh Belas equal to 33,34% from only 57,57 % highly motivated student and very height after cycle I becomes 90,91 % highly motivated student and very height after cycle II,(2) Applying homework and feedback can increase achievement of student learning 11,27 or 20,23 % out of 55,71 after cycle I becomes 66,98 at cycle II.(3) Applying homework giving feedback also can increase number of complete studentsinlearning 9,09 % out of 57,59 % out of 33 students after cycle I becomes 66,67 % as of cycle after II

Four-wave mixing cascades seeded by a multiwavelength Brillouin–erbium fiber laser

Four-wave mixing (FWM) cascades which are seeded by a multiwavelength Brillouin–erbium fiber laser (MBEFL) are experimentally demonstrated in this work. The MBEFL, which is based on virtual mirror feedback, is successful in providing the seed for the FWM cascades. The stimulated Brillouin scattering and parametric gain for the development of the MBEFL and FWM cascades, respectively, are provided by a 12 km dispersion-shifted fiber (DSF). By launching the MBEFL into the DSF, as many as 80 comb lines can be generated when the Brillouin pump (BP) wavelength is tuned at 1560 nm. Analysis of FWM cascades as a function of BP wavelength shows that the number of comb lines is greater at the anomalous-dispersion region of the DSF, suggesting that the phase mismatch is minimized in that regime

Departemen Ilmu Kedokteran Forensik dan Medikolegal Fakultas Kedokteran Universitas Airlangga

Identification include fingerprint, property, medical, dental, serologic and exclusion methods. In the development, identification methods led to molecular forensics, a new field of science evolving since the 1980s, known as DNA fingerprinting. Blood spots/bloods, semen spots, vaginal swabs, buccal swabs and bones are specimens widely used in DNA assay for identification. In addition to these specimens, the last objects often used by the perpetrators/victims can be used, such as hearing aids (headsets/earphones). In its use, earphones are attached to the outer ear skin; thus, the earwax is suspected to adhere to the device. To date, in Indonesia personal identification is performed through swabs of earphones/headsets using the DNA profiling method. In particular, mitochondrial DNA has not been widely used for identification. The present study was of laboratory experimental. Earphones which have been used for 3 days were placed in room temperature for 1, 7, 14 and 20 days. Results showed that the environmental factor of exposure duration had an effect of a significant decrease in the levels of DNA from day 1 to day 20. Only 126-bp mtDNA (HVS II) was detected on the samples of day 1 and continued with sequencing. Mitochondrial DNA has better durability and relatively higher number of copies than those of nuclear DNA. This leads to greater possibility of success in amplification, given the higher number of mitochondrial DNA copies and the fact that mitochondrial DNA is a single locus that allows recombination

Analysis of Open Stub Resonator and its Application in Dual Isolation Band of SPDT Switch Design

In this paper, an analysis of open stub resonator is presented and its application in dual isolation band of Single Pole Double Throw (SPDT) switch is proposed. A mathematical model and the characteristic of the bandstop of the resonator were analyzed and discussed. The open stub resonator was implemented using the microstrip transmission line and able to switch between bandstop and allpass responses. Frequency bands of 2.3 and 3.5 GHz were chosen to demonstrate the dual isolation band in the switch design. The performance results of the SPDT switch showed that the isolation was greater than 30 dB, return loss was greater than 10 dB and insertion loss less than 2 dB at the center resonant frequency of 2.3 and 3.5 GHz. The potential application of the proposed dual isolation band of SPDT switch is for multi band RF front-end system such as WiMAX, LTE, WiFi and HyperLAN