Discontinuous Galerkin method for the spherically reduced BSSN system with second-order operators

We present a high-order accurate discontinuous Galerkin method for evolving the spherically-reduced Baumgarte-Shapiro-Shibata-Nakamura (BSSN) system expressed in terms of second-order spatial operators. Our multi-domain method achieves global spectral accuracy and long-time stability on short computational domains. We discuss in detail both our scheme for the BSSN system and its implementation. After a theoretical and computational verification of the proposed scheme, we conclude with a brief discussion of issues likely to arise when one considers the full BSSN system.Comment: 35 pages, 6 figures, 1 table, uses revtex4. Revised in response to referee's repor

Konsepsi Siswa Kelas XI IPA Negeri 5 Palangka Raya Tentang Senyawa Hidrokarbon Tahun Ajaran 2018/2019

Penelitian merupakan penelitian deskriptif, dilaksanakan di SMA Negeri 5 Palangka Raya pada 80  siswa di kelas XI IPA-1 SMA Negeri 5 Palangka Raya Tahun ajaran 2018/2019. Data penelitian didapat melalui tes uraian siswa dan wawancara siswa. Hasil penelitian menunjukkan bahwa rata-rata kosepsi siswa tertinggi terletak pada konsepsi siswa tantang pengertian senyawa hidrokarbon yaitu sebesar 63,75% dan berada pada kategori tuntas. Konsepsi siswa tentang memberikan nama senyawa hidrokarbon alkana, alkena dan alkuna ialah 34,6% siswa masuk kategori tidak mengerti. Konsepsi siswa tentang membedakan atom C primer, sekunder, tersier dan kuartener ialah 33,125% masuk kategori tuntas dan konsepsi siswa terendah tentang mengelompokan senyawa hidrokarbon berdasarkan kejenuhan ikatan ialah 30% siswa masuk kategori tuntas. Penguasaan konsepsi siswa terbagi kedalam  (empat) kategori yaitu tidak mengerti, tuntas sebagian, mendekati tuntas dan tuntas. Banyak siswa menjawab dengan benar pengertian senyawa hidrokarbon dan menjawab dengan benar perbedaan atom C primer, sekunder, tersier dan kuartener. Banyak siswa tidak mampu menjawab dengan benar mengelompokan senyawa hidrokarbon berdasarkan kejenuhan ikatan dan memberikan nama pada senyawa hidrokarbon

Dinamika N-nh4 Dan N-no3 Akibat Pemberian Pupuk Urea Dan Kapur Caco3 Pada Tanah Inceptisol Kwala Bekala Dan Kaitannya Terhadap Pertumbuhan Tanaman Jagung

The objective of this research were to determine the effect of urea fertilizer and lime-CaCO3applications and its interaction on the dynamics of N-NH4 and N-NO3 and changes in soil pH andgrowth of maize in Inceptisols taken from Kwala Bekala. This research was conducted in thegreenhouse, Chemistry and Soil Fertility Laboratory, at the Faculty of Agriculture, University ofNorth Sumatra, Medan. This study used a randomized block design (RBD) factorial consisting oftwo factors. The first factor was urea (U) which was composed of doses 0, 75, 150 and 225 kg N/haand the second factor was lime-CaCO3 (K) which was composed of doses 0, 2.032, 4.064, 6.096tons CaCO3/ha. The results showed that the application of urea fertilizer, lime-CaCO3 andinteractions increased N-NH4 in the first week and then decreased until the sixth week andincreased the N-NO3 until the fifth week and raised the soil pH in the first and second week thendecreased until the sixth week. The applications of doses urea fertilizer decreased plant height, stemdiameter, shoot dry weight and root dry weight. The application of lime-CaCO3 decreased thegrowth of the maize except the concentration of plant nitrogen. The interaction of urea fertilizer andlime-CaCO3 decreased stem diameter and shoot dry weight

Persepsi dan Tingkat Kepuasan Pelaku USAha terhadap Fasilitas dan Pelayanan di Pelabuhan Perikanan Samudera Nizam Zachman Jakarta (Ppsnzj)

Pengelola Pelabuhan Perikanan Samudera Nizam Zachman Jakarta (PPSNZJ) dan instansi terkait berusaha memenuhi kepentingan para pelaku USAha di PPSNZJ dengan melakukan penyediaan fasilitas dan pelayanan jasa. Penelitian ini bertujuan untuk mengukur kinerja dari PPSNZJ berdasarkan kepuasan para pelaku USAha di PPSNZJ dan mengukur tingkat kepentingan atribut-atribut kinerja PPSNZJ terhadap persepsi kepentingan menurut pelaku USAha. Tingkat kepuasan terhadap fasilitas dan jasa PPSNZJ diukur dengan harapan dan kepuasan stakeholder terhadap 5 kelompok pertanyaan yang terdiri dari tangibility, reliability, responsiveness, assurance dan empathy. Berdasarkan tingkat kepuasan pelaku USAha di PPSNZJ menunjukkan bahwa pelaku USAha sangat puas terhadap kinerja PPSNZJ dengan nilai diatas 80% pada kelima kelompok pertanyaan tersebut, dengan demikian kinerja dari PPSNZJ sudah baik untuk memfasilitasi dan melayani kebutuhan para pelaku USAha. Prioritas yang perlu diutamakan oleh PPSNZJ adalah atribut yang memiliki nilai kepentingan tinggi dan kinerja yang rendah. Berdasarkan hasil importance performance analysis ditemukan 15 atribut yang perlu diprioritaskan oleh PPSNZJ

Natural Frequency of Lightweight Composite Slabs Based On Experimental Study and Numerical Modelling

Recently, lightweight composite slabs have become increasingly popular. Lightweight composite slabs are an innovation that provides a better and more convenient construction method for floor systems. Under dynamic loads, lightweight composite slabs may experience meagre inertia forces due to poor stiffness or low mass. Compared to conventional composite slabs, lightweight composite slabs are 40% lighter and more susceptible to structural resonance. Therefore, the vibration behaviour must be controlled to avoid discomfort issues. This study investigates the natural frequency of lightweight composite slabs through experimental study and numerical modelling. In the experimental study, lightweight composite slabs were prepared for the hammer-impact test. The slab thickness ranges from 100 mm to 200 mm. In numerical modelling, lightweight composite slabs were modelled in SAP2000 using a unique technique called the simplified equivalent plate model. The effective material properties were derived from the rule of mixtures and depend exclusively on elastic properties with strength characteristics. The results of the experimental study and numerical modelling agree positively. The natural frequency decreased with slab thickness, signifying that the natural frequency is dominated by mass rather than stiffness. Overall, the natural frequency of lightweight composite slabs is around 27.23Hz to 31.45Hz