2,976 research outputs found

    Experimental Research on Natural Pozzolan as Cement Replacement

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    This paper presents the properties of motor and concrete with natural pozzolan as partial replacement of cement. In this research, natural pozzolan from Twin Taung, Sagaing Region and local cement (Crown) are used. Firstly, chemical composition of natural pozzolan and Crown cement are analysed. And then the physical properties of local materials used in this research are determined according to ASTM procedure. Partial replacement percentages of pozzolan are considered 10%, 20%, 30% and 40%.The strength of motor and concrete with natural pozzolan (0%,10%, 20%, 30%, and 40%) is tested at 7 days,28 days and 91days. From the trial mix design, the water-cement ratio (0.555) is obtained by using the least square method. To get target strength (4000 psi), by using water cement ratio (0.555) and 68% of maximum aggregate size (20 mm), the concrete mix proportion (1:1.9:3) is obtained.The compressive strength of concrete with various percentages of natural pozzolan at 60 days and 91 days are more than 7 days and 28 days strength. Therefore, it can be concluded that natural pozzolan may be used as cement replacement material when it is not required high strength performance in structures

    Mechanisms that influence the formation of high-ozone regions in the boundary layer downwind of the Asian continent in winter and spring

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    The seasonal variation of ozone (O3) in the boundary layer (BL) over the western Pacific is investigated using a chemistry-transport model. The model results for January and April-May 2002 were evaluated by comparison with PEACE aircraft observations. In January, strong northwesterlies efficiently transported NOx from the continent, leading to an O3 increase of approximately 5-10 ppbv over a distance of about 3000 km. In April, southwesterlies dominated due to anticyclone development over the western Pacific. Along this flow, O3 continued to be produced by NO x emitted from East Asia. This resulted in the formation of a high-O3 (> 50 ppbv) region extending along the coastal areas of East Asia. This seasonal change in O3 was driven in part by a change in the net O3 production rate due to increases in solar UV and H 2O. Its exact response depended on the NOx values in the BL. The net O3 production rate increased between winter and spring over the Asian continent and decreased over the remote western Pacific. Model simulations show that about 25% of the total O3 (of 10-20 ppbv) increase over the coastal region of Northeast Asia was due to local production from NOx emissions from China, and the rest was due to changes in background levels as well as emissions from Korea, Japan, and east Siberia. Uplift of BL air over Asia, horizontal transport in the free troposphere, and subsidence were the principal mechanisms of transporting Asian O3 to the central and eastern North Pacific Copyright 2008 by the American Geophysical Union

    Visualization and Analysis of Sensory Data

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    Recently, California has suffered a severe drought, making water a scarce resource to its population. Many viticulturists are based in this area who rely on heavy irrigation to produce a better grape and a better wine. Not just in California, but throughout the nation, irrigation must be applied intelligently for efficient use of water and funding. By taking measurements of physical characteristics of a vineyard over time, one may be able to visualize trends in the data which lend itself to describing preferred growing methods. Wireless sensors can be used to take measurements including moisture, temperature, sunlight, and more. Sensors have been installed at multiple locations about a vineyard. A framework has been put in place to capture, adjust, and calibrate the data as well as store it for future retrieval. The data are visualized over time to see the effects of techniques in the long term. These are helpful for suggesting irrigation strategy that will lead to the best yield. Sensors are cheap and effective, but are prone to malfunction and transmission errors. When these problems occur, the faulty time-series data can be cleaned by correlating with similar time-series data in the same time span. The data system will be a necessity for competitive viticulturists, reducing cost of irrigation and improving quality of wine. In the future, the tool could be applied to other crops. Also, if any new important values must be derived or measured, the system can be extended to include them

    ANALISIS KINERJA KEUANGAN PERUSAHAAN SUB SEKTOR PERTAMBANGAN SEKTOR BATUBARA YANG TERDAFTAR DI BURSA EFEK INDONESIA PERIODE 2015-2016

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    2018. Faculty of Economics, University August 17, 1945. Financial Performance in the Coal Sector Mining Sub-Sector company listed on the Indonesia Stock Exchange for the 2015-2016 Period, (under Supervisor I Mrs. Titin Ruliana and Supervisor II Mr. Taghfirul Azhima Yoga Siswa).The financial performance based on net profit margin ratio, return on assets, current ratio and quick ratio in the mining sector sub-sector of the coal sector in 2015-2016.The result of this based on profitability ratio analysis of the variable net profit margin (NPM) in the GEMS company (8,51%), ITMG (5,59%), KKGI (5,12%) and MYOH (0,25%). Likewise liquidity ratio in the current ratio (CR) variables in GEMS companies (97,99%), ITMG (45,50%), KKGI (183,14%), MBAP (137,57%) and PTBA (11,21%). And quick ratio (QR) variables in companies in GEMS companies (105,23%), ITMG (60,83%) KKGI (135,71%), MYOH (167,68%) and PTBA (9,64%). the financial performance decreased in 2016 on the variable return on assets (ROA) in MBAP companies (-8,45%), MYOH (-0,9%), PTBA (-1,16%) and TOBA (-3,53 %).The financial performance has increased in 2016 compared to 2015 against the variable net profit margin, current ratio and quick ratio. the variable return on assets (ROA) has decreased in 2016 compared to 201

    Oxygen-Vacancy-Induced Orbital Reconstruction of Ti Ions at the Interface of LaAlO3/SrTiO3 Heterostructures: A Resonant Soft-X-Ray Scattering Study

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    Resonant soft-x-ray scattering measurements have been performed to investigate interface electronic structures of (LaAlO3/SrTiO3) superlattices. Resonant scattering intensities at superlattice reflections show clear evidence of degeneracy lifting in t(2g) states of interface Ti ions. Polarization dependence of intensities indicates the energy of d(xy) states is lower by similar to 1 eV than two other t(2g) states. The energy splitting is insensitive to epitaxial strain. The orbital reconstruction is induced by oxygen vacancies and confined to the interface within two unit cells, indicating charge compensation at the polar interfaces. DOI: 10.1103/PhysRevLett.110.017401X112723Nsciescopu
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