981 research outputs found

    Effects of advera® warm mix additive on the rheological properties of unaged and short term aged asphalt binders

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    The performance of asphalt pavement is mainly governed by the properties of the binder. Many asphalt pavement distress are pronounced to be related to the rheological properties of asphalt binder. The oxidation changes the structure and composition of asphalt binder resulting stiffer and brittle of asphalt. This paper described SuperpaveTM binder that was used to characterize the rheological properties of PG64 asphalt binders blended with various Advera® contents subjected to unaged and short term aged. Rotational viscometer (RV) and Dynamic Shear Rheometer (DSR) were conducted to measure binder properties at higher and intermediate temperature respectively. The results indicated that, the addition of Advera® in the asphalt binder exhibited change in binder rheology which influenced rutting parameteryKeywords: Advera®; Aging; Viscosity; Rotational viscometer; Dynamic shear rheometer

    Motivasi Dan Kemampuan Berpikir Tingkat Tinggi Siswa Setelah Pembelajaran Kimia Dengan Strategi Inkuiri Terbimbing

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    Motivasi dan Kemampuan Berpikir Tingkat Tinggi Siswa Setelah Pembelajaran Kimia Dengan Strategi Inkuiri Terbimbing. Tujuan penelitian ini adalah untuk mengetahui pengaruh strategi inkuiri terbimbing terhadap motivasi dan kemampuan berpikir tingkat tinggi siswa pada pembelajaran hi­drolisis. Penelitian eksperimen semu ini menggunakan pretest-postest control group design. Subjek pe­nelitian adalah dua kelas XI IPA dengan rerata kemampuan yang setara, yaitu kelas XI IPA 1 (kelas eks­positori) dan kelas XI IPA 3 (kelas inkuiri terbimbing) SMA Negeri 6 Malang tahun pelajaran 2013/2014. Ketiga instrumen pengukuran yaitu tes motivasi, tes kemampuan berpikir tingkat tinggi yang terdiri dari tes pemahaman konseptual dan algoritmik serta tes kemampuan logika deduktiv, telah diuji coba dan menun­jukkan bahwa ketiganya valid dan reliabel. Perbedaan hasil tes di kedua kelas dianalisis dengan uji MA­NOVA. Hasil penelitian menunjukkan bahwa motivasi belajar dan kemampuan berpikir tingkat tinggi, baik dalam bentuk pemahaman konseptual dan pemahaman algoritmik, maupun kemampuan logika de­duktif, dari siswa yang dibelajarkan dengan strategi inkuiri terbimbing adalah lebih tinggi dibanding siswa yang dibelajarkan dengan strategi ekspositori

    Rutting assessment of crumb rubber modifier modified warm mix asphalt incorporating warm asphalt additive

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    Warm Mix Asphalt (WMA) as a green technology, permits production of asphalt mixtures at lower temperatures compared to conventional HMA; emissions and energy consumption reduction, were among the key success of this technology, thus, enhancing social, economic, and environmental sustainability. But due to the reduced production temperature, WMA are more prone to rutting, to improve the rutting resistance of WMA mixtures and minimize pollution resulting from waste rubber tire. Therefore, the effect of wet processed Crumb Rubber Modifier (CRM) on rutting depth of WMA mixtures incorporating 2.5% Sasobit by weight of base binders were assessed in the laboratory. In this study, the asphalt mixtures were fabricated in accordance with Superpave, using; crush granite aggregate of 9.5mm NMAS and the four binders that were produced by blending the PG 64 binder with different contents of 40 mesh size CRM (0%, 5%, 10%, and 15%, by weight of the base binder). Rutting depths of the mixtures were assessed on 150mm diameter and 70mm thick cylindrical samples using wheel tracker, the wheel tracking test were carried out at 45oC and 60oC, in accordance with BS 598 Part 110 (1998). Based on the results of wheel tracking tests, CRM could improve the resistance of the WMA mixtures to rutting. It was also found from statistical Analysis of Variance (ANOVA), that the two influence factors; CRM, and the test temperature both having p-values less than the assumed significance at 95% confidence level, therefore they have significant effect on rutting in WMA

    Perancangan dan Pembuatan Sistem Penebar Pakan Ikan Jenis Pasta Otomatis Berbasis Mikrokontroler At89s51

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    Indonesia is an agricultural country with abundant natural resources, including fishery. Fishermen are found almost throughout parts of Indonesia with different size pool or pond. Manually feeding is ineffective because of the number of fish's food used was not always fixed even if it takes a long time feeding evenly throughout the pool. Spreader tool forage fish species AT89S51 microcontroller-based pasta has been made to provide the feed of pasta with fixed volumes levelled DC motor based machine

    Isospin effects on the energy of vanishing flow in heavy-ion collisions

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    Using the isospin-dependent quantum molecular dynamics model we study the isospin effects on the disappearance of flow for the reactions of 58Ni^{58}Ni + 58Ni^{58}Ni and 58Fe^{58}Fe +58Fe^{58}Fe as a function of impact parameter. We found good agreement between our calculations and experimentally measured energy of vanishing flow at all colliding geometries. Our calculations reproduce the experimental data within 5%(10%) at central (peripheral) geometries

    Influence de quelques facteurs environnementaux sur la germination d'Euphorbia heterophylla L. (Euphorbiaceae)

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    Influence of some Environmental Factors on Euphorbia heterophylla L. (Euphorbiaceae) Seeds Germination. In Ivory Coast, Euphorbia heterophylla appears as a weed in cotton fields. Effects of temperature, light and burying levels on its seed germination were tested. Temperature effects were monitored by means of 4 procedures, using a range of temperatures between 20 and 35 °C. The germination latency period can vary between 1 and 2 days, according to the temperature. After 4 days, germination rates were not longer related to temperature and were very similar. Germination can not happen without light. In order to measure the effect of burying levels, six series of 100 seeds were buried; the first at ground level, the others respectively 2, 4, 6, 8 and 9 cm deeper. Optimal germination rates were found for seeds that were buried between 0 and 6 cm

    Physical Characterization of Modified Asphalt Binder with Differing Fly Ash Geopolymer Contents

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    Nowadays, the use of waste material product has gained popularity in the production of asphalt mixes and becomes a cost-effective method of pavement construction that can decrease the consumption of natural resources and to reduce environmental pollution. This research aimed to investigate the possibility of using waste and by-product material namely fly ash geopolymer additive to influence the physical properties of asphalt binder. An experimental matrix of laboratory testing was conducted to study the properties of the 60/70 and 80/100 asphalt binder with modified binder containing 3%, 5%, 7%, 9% and 11% of fly ash geopolymer additive. The physical properties of the binders were determined using the penetration, softening, penetration index, ductility, and rotational viscosity respectively. The results indicated that, the fly ash geopolymer modified binder had improved the physical properties over base binder. The thermal susceptibility also improved by referring to the Penetration Index value. Overall research conclusions are that geopolymer application resulted in a potential enhancement of some of the properties of the asphalt binder and increase the performance of asphalt binder in the pavement application

    On the Downlink Coverage Performance of RIS-Assisted THz Networks

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    This letter provides a stochastic geometry (SG)-based coverage probability (CP) analysis of an indoor terahertz (THz) downlink assisted by a single reconfigurable intelligent surface (RIS) panel. Specifically, multiple access points (AP) deployed on the ceiling of a hall (each equipped with multiple antennas) need to serve multiple user equipment (UE) nodes. Due to presence of blockages, a typical UE may either get served via a direct link, the RIS, or both links (the composite link). The locations of the APs and blockages are modelled as a Poisson point process (PPP) and SG framework is utilized to compute the CP, at a reference UE for all the three scenarios. Monte-Carlo simulation results validate our theoretical analysis.Comment: Extended Arxiv version of submitted paper to IEEE Communications Letter
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