5,393 research outputs found
Characterization of the Structure of Saudi Crude Asphaltenes by X-ray Diffraction
Structural characterization studies have been carried out on four commercial Saudi Arabian
crude oils. The aromaticity and crystallite parameters of the asphaltenes were studied by X-ray
diffraction methods and compared to the average structural parameters calculated from nuclear
magnetic resonance spectra
Oil palm leaf fibre and its suitability for paper-based products
Due to the shortage of wood as origin materials for paper-based production, agro-residue materials have been explored in the quest of finding the best alternative fibre. Oil palm leaf (OPL) is one of agro-residue that has potential due to its comparable characteristics with wood fibre. Studies on chemical compositions, fibre morphology, and mechanical property of OPL have been carried out aiming to evaluate its potential as a substitute raw material for pulp and paper-based production. The chemical compositions were analysed according to the TAPPI standard, Kurscher-Hoffner and chlorite methods accordingly. The mechanical property (tensile, tearing and bursting strengths) were determined as described in TAPPI test methods. Fibre dimensions were determined using Franklin method and analysed under the optical microscope. The content of cellulose in the OPL is determined to be 43.8%. Although, this result is lower than wood fibre (53%), OPL has higher hemicellulose content (36.4%) than the wood fibre (27.5%). In addition, the lignin content (19.7%) of OPL is in the low range of those in wood resources (18 - 25%). These parameters are important components to produce good quality pulp and will provide high mechanical strength of the paper-based products. The measured fibre length of oil palm leaf (1.13 mm) is shorter than the wood fibre (1.90 mm). Meanwhile, the mechanical property of OPL showed lower indexes than wood resources, however, tear (1.80 mN.m2/g) and burst (0.95 kPa.m2/g) indexes of OPL are higher than other published and successful wood resources (Eucalyptus). Based on the analyses, the oil palm leaf is indeed a suitable alternative of raw material for pulp and paper-based industries
New Hybrid Non-Dominated Sorting Differential Evolutionary Algorithm
This paper presents a new multi objective optimization algorithm with the aim of complete coverage, faster global convergence and higher solution quality. In this technique, the high-speed characteristic of particle swarm optimization (PSO) is combined with non-dominated differential evolutionary (NSDE) and an efficient multi objective optimization algorithm is created. This method posses high convergence characteristic in quite less execution times. Generating fewer populations to find the Pareto front also makes the proposed algorithm use less memory. For the purpose of performance evaluation, the algorithm is verified with four benchmarking functions on its global optimal search ability and compared with two recognized algorithm to assess its diversity. The capability of the suggested algorithm in solving practical engineering problems such as power system protection is also studied and the results are discussed in detail
Kajian Kehidupan dan Kegiatan Akademik Para Mahasiswa Raja Panggung Jalanan di Universitas Muhammadiyah Makassar
Telah dilakukan penelitian yang bertujuan untuk mengetahui (1) kehidupan akademik para raja panggung jalanan di Universitas Muhammadiyah Makassar, (2) untuk mengetahui kegiatan akademik para raja panggung jalanan di Universitas Muhammadiyah Makassar, (3) untuk mengetahui kapan dan situasi seperti apa para raja panggung jalanan turun ke jalan melakukan aksi demonstrasi di Universitas Muhammadiyah Makassar. Penelitian ini bersifat deskriptif dengan tipe kualitatif untuk mendeskripsikan kehidupan dan kegiatan akademik para raja panggung jalanan di Universitas Muhammadiyah Makassar. Penentuan lokasi penelitian ini dilakukan secara purposive random sampling dengan memilih Universitas Muhammadiyah Makassar sebagai lokasi penelitian, dengan penentuan informan menggunakan teknik purposive random sampling yaitu informan yang memiliki ciri-ciri yang sesuai diperlukan sebagai sumber data. Teknik pengumpulan data menggunakan teknik (1) studi pustaka, (2) pengamatan, (3) wawancara, (4) dokumentasi. Teknik analisis data yang digunakan adalah analisis data Model Miles dan Huberman yang terdiri dari reduksi data (data reduction), model data (data display) dan kesimpulan/verifikasi (conclusion/verification). Hasil penelitian menunjukkan bahwa aksi demonstrasi kampus banyak merugikan masyarakat, merugikan diri mereka sendiri, dan utamanya merugikan kampus mereka, seperti halnya yang terjadi di Universitas Muhammadiyah Makassar. Selain itu kegiatan akademik para raja panggung seperti kegiatan intra kampus seperti IMM, kegiatan ekstra kampus seperti Himpunan Mahasiswa Islam (HMI), Wahdah, dan organda dari masing-masing daerah para raja panggung. Aktivitas mahasiswa sebagian besar dilakukan ketika memperingati hari-hari besar, dan adanya isu-isu dari berbagai bidang seperti bidang budaya, sosial, pendidikan, ekonomi hingga sampai pengawalan isu-isu politik, aksi-aksi demonstrasi tersebut telah direncanakan, diskusikan, dan disepakati terlebih dahulu baik dari segi teknis, tempat, waktu yang akan digunakan untuk demo dan kemungkinan-kemungkinan negatife yang nantinya terjadi dijalanan atau yang menganggu aksi tersebut
Generalized Konishi anomaly, Seiberg duality and singular effective superpotentials
Using the generalized Konishi anomaly (GKA) equations, we derive the
effective superpotential of four-dimensional N=1 supersymmetric SU(n) gauge
theory with n+2 fundamental flavors. We find, however, that the GKA equations
are only integrable in the Seiberg dual description of the theory, but not in
the direct description of the theory. The failure of integrability in the
direct, strongly coupled, description suggests the existence of
non-perturbative corrections to the GKA equations.Comment: 20 pages; v3: corrected the comparison to the SU(2) cas
Penerapan Model Pembelajaran Teams Games Tournament (Tgt) Dengan Kartu Destinasi Untuk Meningkatkan Aktivitas Dan Hasil Belajar Siswa Pada Materi Sistem Periodik Unsur Kelas X Mia 3 Di SMA Batik 1 Surakarta Tahun Ajaran 2014/2015
Penelitian ini bertujuan untuk meningkatkan: (1) aktivitas belajar siswa kelas X MIA 3 SMA Batik 1 Surakarta melalui penerapan model pembelajaran Teams Games Tournament (TGT) dengan kartu destinasi pada materi sistem periodik unsur (2) hasil belajar siswa X MIA 3 SMA Batik 1 Surakarta melalui penerapan model pembelajaran Teams Games Tournament (TGT) dengan kartu destinasi pada materi sistem periodik unsur. Penelitian ini merupakan Penelitian Tindakan Kelas (Classroom Action Research) terdiri dari dua siklus. Subjek penelitian adalah siswa kelas X MIA 3 SMA Batik 1 Surakarta Tahun Pelajaran 2014/2015. Pengumpulan data diperoleh melalui wawancara, observasi, tes dan angket. Teknik analisis data menggunakan teknik analisis deskriptif kualitatif. Hasil penelitian menunjukan bahwa model pembelajaran Teams Games Tournament (TGT) dengan kartu destinasi pada materi sistem periodik unsur kelas X MIA 3 SMA Batik 1 Surakarta tahun pelajaran 2014/2015 dapat meningkatkan: (1) aktivitas belajar siswa dengan persentase sebesar 71,99% pada siklus I meningkat menjadi 73,35% pada siklus II. (2) hasil belajar siswa berupa aspek pengetahuan dan sikap. Hasil belajar aspek pengetahuan siklus I memiliki persentase 44,18% meningkat menjadi 79,07% pada siklus II. Hasil belajar aspek sikap siswa siklus I memiliki persentase 77,69% meningkat menjadi 82,49% pada siklus I
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