547 research outputs found

    Synchrotron Polarization at High Galactic Latitude

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    We present preliminary results from mapping the high-latitude Galactic polarization with the Effelsberg Telescope at λ\lambda21 cm. Structures on the resulting maps are mostly on the scale of several degrees. The results show detection of polarization over most of the field, at the level of tens of percent of the synchrotron emission. The evidence of more structure in Stokes Q and U rather than in Q2+U2\sqrt{Q^2+U^2} suggests the existence of Faraday rotation.Comment: To be published in the proceedings of "The Cosmic Microwave Background and its Polarization", New Astronomy Reviews, (eds. S. Hanany and K.A. Olive

    SNR Analysis On L-Band Mobile Satellite System Under Building Effect

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    This paper presents the method to analyse the effect of building on the L-band Mobile Satellite (MS) system using low-power Global Positioning System (GPS) receiver. The method includes measurement, experimental and data analysis. The analysis of the signal performance under building effect measurement was carried out with respect to the signal to noise ratio (SNR), elevation and azimuth angle. In measurement method, the National Marine Electronics Association (NMEA) sentences obtained from the satellite via GPS receiver was used to get the signal propagation parameters. The NMEA Extractor used to extract the NMEA data using C++ programming language and Ngraph software to construct the graphical presentation for analysis method. The analysis shows relationship between SNR and elevation and azimuth angle. The comparison between open space and building effect was carried out and the results have shown that the presence of the building affect the quality of the satellite signal received

    Open innovation and social media use towards informatics reporting: a systematic literature review

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    In the realm of technology development, open innovation paradigm and social media have both acquired massive attention in extensive researches since past several years. Social media, as the key medium has abundant to offer to support open innovation, thus successful innovation is the key to business rapid growth. This research provides a systematic literature review to identify, classify and summarize the factors of open innovation and social media use towards informatics reporting. Informatics reporting through this dynamic channel have been realized by many organizations nowadays, nonetheless greater number still confine with the traditional reports and are not ready to have linkage with social media platforms. Social media has been absolutely recognized as a powerful communication resource to engage stakeholders in virtual community. Hence, the result from the review suggests that there were six factors impacted open innovation and social media use towards informatics reporting, with transparency being the dominant factor. Eventually, these findings may ease the process of developing a model for open innovation paradigm implementing online platforms in organizations informatics reporting. All in all, this research shall assist organizations to plan and strategize the implementation of open innovation in social media platform for the advantage of their succeeding triumph

    Hybrid Wind Speed Prediction Model Using Intrinsic Mode Function (IMF) and Gradient Boosted Machine (GBM)

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    Before sitting a wind turbine, reliable wind speed prediction is prerequisite requirements that must be performed in order to get optimum energy yield. Single model has a lot of constraints in terms of prediction accuracy, to solve this persistent problem, this paper presents the application of hybrid model based on IMF and GBM so as to predict the wind speed in the areas with limited or absent of data. In the first place, the observed wind speed was decomposed into six using IMF in order to reduce ill-define stochastic nature of wind speed. The decomposed wind speed was used to train, test and validate the model developed GMB model which was developed in a Matlab environment. The final predicted values are obtained by summing all the individual prediction sub models. Wind speed data observed in the existing wind stations in Sarawak for a period of 1 year from 2017 to 2018 were used for the simulation. The model implementation confirmed that the proposed model is robust and capable to predict wind speed in remote and rural areas. A comparison with conventional method (ARIMA) was further investigated, the results showed the superiority of the new hybrid model over ARIMA

    KONVERSI SAMPAH PLASTIK STYROFOAM MENJADI BAHAN PEMBERSIH SULFUR LIGHT DIESEL OIL

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    KONVERSI SAMPAH PLASTIK STYROFOAM MENJADI BAHAN PEMBERSIH SULFUR LIGHT DIESEL OIL. Sampah plastik styrofoam dimanfaatkan sebagai bahan utama untuk isolasi polistiren, yang kemudian disintesis menjadi Natrium N-kloro-polistiren sulfonamida (PI) yang dapat menyerap sulfur di dalam minyak diesel. PI ini digunakan pada proses desulfurisasi minyak diesel ringan dan dapat digunakan kembali setelah melalui proses regenerasi menggunakan solvent washing. Hasil penelitian menunjukkan proses isolasi polistiren menghasilkan polistiren yang memiliki karakteristik dan struktur molekul yang menyerupai polistiren standar. PI juga berhasil mendesulfurisasi minyak diesel dari 1491 ppm menjadi 463 ppm. Proses desulfurisasi ini dapat dilakukan dengan menggunakan polimer PI hasil regenerasi namun dengan hasil yang tidak sebaikmenggunakan polimer PI baru. Proses regenerasi terbaik dilakukan denganmenggunakan kombinasi pelarut toluen dan NaOCl dengan hasil yang dapat mengurangi kadar sulfur dari 1491 ppm menjadi 603 ppm

    Flow Characterization of Vapor Phase of Geothermal Fluid in Pipe Using Isotope 85Kr and Residence TIME Distribution Modeling

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    Measurement of vapor flow in geothermal pipe faces great challenges due to fast fluids flow in high-temperature and high-pressure environment. In present study the flow rate measurement has been performed to characterization the geothermal vapor flow in a pipe. The experiment was carried out in a pipe which is connected to a geothermal production well, KMJ-14. The pipe has a 10” outside diameter and contains dry vapor at a pressure of 8 kg/cm2 and a temperature of 170 oC. Krypton-85 gas isotope (85Kr) has been injected into the pipe. Three collimated radiation detectors positioned respectively at 127, 177 and 227m from injection point were used to obtain experimental data which represent radiotracer residence time distribution (RTD) in the pipe. The last detector at the position of 227 m did not respond, which might be due to problems in cable connections. Flow properties calculated using mean residence time (MRT) shows that the flow rate of the vapor in pipe is 10.98 m/s, much faster than fluid flow commonly found in various industrial process plants. Best fitting evaluated using dedicated software developed by IAEA expert obtained the Péclet number Pe as 223. This means that the flow of vapor of geothermal fluids in pipe is plug flow in character. The molecular diffusion coefficient is 0.45 m2/s, calculated from the axial dispersion model. Received: 21 November 2013; Revised: 16 May 2014; Accepted: 23 May 201

    Degradation and stability of polymer: A mini review

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    Observations of alterations in the structural and chemical properties have been commonly performed to understand the process by which polymers degrade. The validity of each observational procedure depends primarily on the test material and type of degradation. An appropriate method for the characterization of polymers can often be utilized to examine the properties of degradation. The service life of a polymer depends strongly on the conditions to which the material is subjected. On the other hand, the stability of the material, including nanocomposite polymer blends, often dictates its usefulness. Thus, this review was aimed to evaluate the degradation of nanocomposite polymer blends, with specific focus on the role of the fillers and the composition of the blends. The factors that could significantly affect the degradation of the same were the presence of a filler, as well as the morphology and composition of the blends

    A short review on polymeric materials concerning degradable polymers

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    The demand for cutting-edge functional materials has been increasing since the decade. Polymeric materials usage in the past decade contributes to its commercial accomplishment, thus encouraging more groundbreaking research-based activities. Although this news is promising for polymer-related industries, the fast consumption rate of these materials throughout the world will seriously harm the environment through the accumulation of waste materials sourced primarily from by-products, faulty products or municipal from various agricultural farms and industries with disposal difficulties. Wide usage of polymeric materials is due to their ease of processing, light weight and relatively low manufacturing cost. Various advancements were made over the years in developing polymeric materials of high performance. Structure and ionic bonds of polymeric and biomaterials are the reason behind their physical and chemical properties. However, their usage is limited due to expensive manufacturing cost and difficulty in shaping and processing them
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