645 research outputs found

    Life without the Beach: Projected Sea Level Rise and its Impact on Barrier Islands Along the East Coast, USA

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    As climate change is becoming a global issue, the impact of sea level rise is increasingly becoming a threat to humans, wildlife, infrastructure, and ecosystems. To evaluate the effects of sea level rise on barrier islands and coastal regions, we studied future projections of sea level rise at Ocean City and Assateague Island, Maryland. We hypothesize that the sea levels at Assateague and Ocean City will have different beach profiles, and will show different levels of flooding through the Representative Concentration Pathways (RCP) simulations. We measured beach profiles at four locations, two at Ocean City and two at Assateague Island, to view the current beach profiles and found that Ocean City reveals a smaller average change in elevation compared to Assateague. We also used a LiDAR Digital Elevation Model (DEM) of Ocean City and Assateague Island to run RCP 2.6, RCP 4.5, and RCP 8.5 simulations using GIS to represent the Intergovernmental Panel on Climate Change (IPCC) projected sea level rise for the year 2100. We found that Ocean City has higher predicted percentages of flooded land but smaller areas of flooded land compared to Assateague. These results indicate that significant areas of both Ocean City and Assateague Island will be flooded by 2100 regardless of which RCP simulation might be true. However, it is projected that the RCP 2.6 simulation is an underestimation of potential flooding and the future will more closely resemble the RCP 8.5 simulation if drastic precautions are not taken now. This will severely impact ecosystems, economies, and human life

    Unconventional superconductivity in the cage type compound Sc5_5Rh6_6Sn18_{18}

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    We have examined the superconducting ground state properties of the caged type compound Sc5_5Rh6_6Sn18_{18} using magnetization, heat capacity, and muon-spin relaxation or rotation (μ\muSR) measurements. Magnetization measurements indicate type-II superconductivity with an upper critical field μ0Hc2(0)\mu_0H_{c2}(0) = 7.24 T. The zero-field cooled and field cooled susceptibility measurements unveil an onset of diamagnetic signal below TcT_{\bf c} = 4.4 K. The interpretation of the heat capacity results below TcT_{\bf c} using the α\alpha-BCS model unveils the value of α\alpha = 2.65, which gives the dimensionless ratio 2Δ(0)/kBTc\Delta(0)/k_B T_{\bf c} = 5.3, intimating that Sc5_5Rh6_6Sn18_{18} is a strong-coupling BCS superconductor. The zero-field μ\muSR measurements in the longitudinal geometry exhibit a signature of a spontaneous appearance of the internal magnetic field below the superconducting transition temperature, indicating that the superconducting state is characterized by the broken time-reversal symmetry (TRS). We have compared the results of broken TRS in Sc5_5Rh6_6Sn18_{18} with that observed in R5_5Rh6_6Sn18_{18} (R = Lu and Y).Comment: 6 pages, 4 figures. arXiv admin note: text overlap with arXiv:1411.687

    KEMAMPUAN PEMAHAMAN KONSEP MATEMATIS SISWA PADA PEMBELAJARAN MODEL RME

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    This research aimed to produce a study of students' mathematical concept understanding abilities in classes with Realistic Mathematics Education (RME) model learning and classes that did not receive RME model learning. This research was a quantitative method of quasi experiment model designed in the form of non-equivalent control group design involving two research classes determined using purposive sampling technique. The instrument used was a test of students' mathematical concept understanding ability in the form of description questions. The data analysis technique in this study used an independent sample t-test and N-gain score. The results of the analysis showed that students' mathematical concept understanding ability in the class that received RME model learning was better than that of those who did not receive RME model learning. The increase in students' mathematical concept understanding ability in the class with RME model learning was in a low category with an average gain score of 0.025. The low increase is due to the limited learning time at school during the adaptation period of new habits, so that learning with the RME model does not run effectively

    TINGKAH LAKU IKAN CUPANG (Betta splendes) TERHADAP PAKAN YANG BERBEDA

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    Ikan cupang (Betta splendes) adalah salah satu ikan hias air tawar di daerah tropis (Linke, 1994). Salah satu keistimewaan ikan cupang adalah daya tarik pada warna yang dimunculkan dari tubuhnya seperti bentuk, tampilan dan warnanya (Susanto, 1992). Fungsi utama pakan adalah untuk kelangsunan hidup dan pertumbuhan (Mujiman, 1992). Tingkah laku ikan terhadap pakan secara umum mempunyai dua pola yaitu aktif mencari pakan pada siang hari (diurnal) dan malam hari (nokturnal). Untuk ikan cupang termasuk tipe diurnal (Mudjiman, 2008). Penelitian ini bertujuan untuk mengetahui tingkah laku atau respon ikan cupang (Betta splendes) terhadap pakan yang berbeda dan untuk mengetahui pertumbuhan dan sintasan hidup ikan cupang (Betta splendes). Wadah yang digunakan dalam penelitian adalah toples kaca sebanyak 9 buah. Ikana cupang yang menjadi obyek penelitian sebanyak 9 ekor. Pakan yang diberikan adalah pakan cacing sutra (Tubifex sp), cacing darah, dan pelet “Takari” sebanyak 2 (dua) kali dalam sehari secara “ed libitum”. Respon makan ikan cupang berbeda-beda, dimana pemberian cacing sutra adalah kurangaktif, pakan cacing darah adalah sangat aktif dan pakan Takari adalah aktif. Pertumbuhan panjang rata-rata ikan cupang yang tertinggi pada wadah B (cacing darah) yaitu 3,3 cm dan diikuti wadah C (pakan Takari) yaitu 3,0 cm dan wadah A (cacing sutra) yaitu 2,9 cm. Pertambahan berat rata-rata yang tertinggi pada wadah B (cacing darah) yaitu 1,50gr, sedangkan wadah C (pakan Takari) yaitu 1,20 gr dan wadah A (cacing sutra) yaitu 1,07gr. Tingkat keberhasilan hidup ikan cupang (B.splendes) untuk semua wadah pemeliharaan adalah 100%

    Broken time-reversal symmetry probed by muon spin relaxation in the caged type superconductor Lu5Rh6Sn18

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    The superconducting state of the caged type compound Lu5Rh6Sn18 has been investigated by using magnetization, heat capacity, and muon spin relaxation or rotation (?SR) measurements, and the results interpreted on the basis of the group theoretical classifications of the possible pairing symmetries and a simple model of the resulting quasiparticle spectra. Our zero-field ?SR measurements clearly reveal the spontaneous appearance of an internal magnetic field below the transition temperature, which indicates that the superconducting state in this material is characterized by broken time-reversal symmetry. Further, the analysis of the temperature dependence of the magnetic penetration depth measured using the transverse-field ?SR measurements suggests an isotropic s?wave character for the superconducting gap. This is in agreement with the heat capacity behavior, and we show that it can be interpreted in terms of a nonunitary triplet state with point nodes and an open Fermi surface

    Investigation of Superconducting Gap Structure in HfIrSi using muon spin relaxation/rotation

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    Appearance of strong spin-orbit coupling (SOC) is apparent in ternary equiatomic compounds with 5dd-electrons due to the large atomic radii of transition metals. SOC plays a significant role in the emergence of unconventional superconductivity. Here we examined the superconducting state of HfIrSi using magnetization, specific heat, zero and transverse-field (ZF/TF) muon spin relaxation/rotation (μ\muSR) measurements. Superconductivity is observed at TCT_\mathrm{C} = 3.6 K as revealed by specific heat and magnetization measurements. From the TFμ-\muSR analysis it is clear that superfluid density well described by an isotropic BCS type ss-wave gap structure. Furthermore, from TFμ-\muSR data we have also estimated the superconducting carrier density nsn_\mathrm{s} = 6.6 ×\times1026^{26}m3^{-3}, London penetration depth λL(0)\lambda_{L}(0) = 259.59 nm and effective mass mm^{*} = 1.57 mem_{e}. Our zero-field muon spin relaxation data indicate no clear sign of spontaneous internal field below TCT_\mathrm{C}, which implies that the time-reversal symmetry is preserved in HfIrSi. Theoretical investigation suggests Hf and Ir atoms hybridize strongly along the cc-axis of the lattice, which is responsible for the strong three-dimensionality of this system which screens the Coulomb interaction. As a result despite the presence of correlated dd-electrons in this system, the correlation effect is weakened, promoting electron-phonon coupling to gain importance.Comment: 8 pages, 4 figure

    Probing the superconducting ground state of ZrIrSi: A μ\muSR study

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    The superconducting ground state of newly reported ZrIrSi is probed by means of μ\muSR technique along with resistivity measurement. The occurrence of superconductivity at TCT_\mathrm{C} = 1.7 K is confirmed by resistivity measurement. ZF-μ\muSR study revealed that below TCT_\mathrm{C}, there is no spontaneous magnetic field in the superconducting state, indicates TRS is preserved in case of ZrIrSi. From TF-μ\muSR measurement, we have estimated the superfluid density as a function of temperature, which is described by an isotropic ss-wave model with a superconducting gap 2Δ(0)/kBTC2\Delta(0)/k_\mathrm{B}T_\mathrm{C} = 5.1, indicates the presence of strong spin-orbit coupling. {\it Ab-initio} electronic structure calculation indicates that there are four bands passing through the Fermi level, forming four Fermi surface pockets. We find that the low-energy bands are dominated by the 4d4d-orbitals of transition metal Zr, with substantially lesser weight from the 5d5d-orbitals of the Ir-atoms.Comment: 6 pages, 4 figure

    Analisa Kelayakan Tarif Angkutan Umum Dalam Kota Kupang

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    Penentuan besaran tarif angkutan membutuhkan penanganan dan kebijakan yang arif karena dapat menjembatani kepentingan penumpang selaku konsumen dan pengusaha selaku operator angkutan umum. Penelitian ini bertujuan untuk mengetahui Biaya Operasi Kendaraan (BOK) dan tarif yang layak diberlakukan untuk trayek angkutan umum Kota Kupang dengan jarak terpendek dan jarak terpanjang. Trayek Terminal Kupang-Penfui adalah trayek angkutan Kota Kupang dengan jarak terpanjang (28,30 km) yang melayani kawasan pertokoan, pendidikan dan kawasan Perumahan, sedangkan trayek Terminal Kupang-Perumnas merupakan trayek angkutan kota dengan jarak terpendek (7,68 km) yang melayani kawasan pendidikan dan Perumahan. Kedua trayek ini memiliki penentuan tarif angkutan yang sama yaitu Rp 2000,- untuk pelajar dan Rp 3000,- untuk masyarakat umum. Analisa BOK dan kelayakan tarif dilakukan dengan metode perhitungan berdasarkan Keputusan Direktur Jenderal Perhubungan Darat Nomor: SK.687/AJ.206 /DRJD/2002 tentang Pedoman Teknis Penyelenggaraan Angkutan Penumpang Umum di Wilayah Perkotaan Dalam Trayek Tetap dan Teratur. Hasil analisa BOK untuk trayek Terminal Kupang-Penfui sebesar Rp 2.165,42/penumpang dan tarif yang layak diberlakukan sebesar Rp 2.381,96/penumpang, sedangkan BOK untuk trayek Terminal Kupang-Perumnas sebesar Rp 1.956,31/penumpang dan tarif yang layak diberlakukan sebesar Rp 2.151,94/penumpang. Determining the amount of transport fares require wise policy for it can bridge the interests of passengers as consumers and businessman as public transport operators. This study aims to determine the Vehicle Operating Cost (VOC) and the decent fares applied in Kupang City for the shortest and the longest route. The route of Terminal Kupang-Penfui is the longest ones that has a distance of 28.30 km, that serves the shopping area and the educational and residential areas; while the route of Terminal Kupang-Perumnas is the shortest route (7.68 km) which serves educational and residential area. Nowadays these two routes have the same transport fares is Rp. 2000, - for students and Rp 3,000, - for public in general. VOC and feasibility fare analysis conducted by the method of the Directorate General of Land Transportation No. SK.687/AJ.206/DrJD/2002. The VOC analysis results for Terminal Kupang-Penfui route is Rp. 2165.42 / passenger and the decent fare imposed is Rp. 2381.96 / passenger; while the VOC for Terminal Kupang-Perumnas is Rp 1956.31 / passenger and the decent fare imposed is Rp. 2151.94 / passenger
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