5,360 research outputs found

    Langmuir dark solitons in dense ultrarelativistic electron-positron gravito-plasma in pulsar magnetosphere

    Full text link
    Nonlinear propagation of electrostatic modes in ultrarelativistic dense elelectron-positron gravito-plasma at the polar cap region of pulsar magnetosphere is considered. A nonlinear Schr\"{o}dinger equation is obtained from the reductive perturbation method which predicts the existence of Langmuir dark solitons. Relevance of the propagating dark solitons to the pulsar radio emission is discussed.Comment: 6 pages, 7 figures. Accepted for publication in Astrophysics and Space Science. arXiv admin note: text overlap with arXiv:astro-ph/9808047 by other authors without attributio

    Non-Markovian incoherent quantum dynamics of a two-state system

    Full text link
    We present a detailed study of the non-Markovian two-state system dynamics for the regime of incoherent quantum tunneling. Using perturbation theory in the system tunneling amplitude Δ\Delta, and in the limit of strong system-bath coupling, we determine the short time evolution of the reduced density matrix and thereby find a general equation of motion for the non-Markovian evolution at longer times. We relate the nonlocality in time due to the non-Markovian effects with the environment characteristic response time. In addition, we study the incoherent evolution of a system with a double-well potential, where each well consists several quantized energy levels. We determine the crossover temperature to a regime where many energy levels in the wells participate in the tunneling process, and observe that the required temperature can be much smaller than the one associated with the system plasma frequency. We also discuss experimental implications of our theoretical analysis.Comment: 10 pages, published versio

    Pengembangan Buku Ajar Berbasis Penelitian Evolusi dan Filogenetik Molekuler untuk Matakuliah Evolusi di Universitas Jember

    Get PDF
    Molecular phylogeneticis a material which studied in Evolution Subject for undergraduete student in Biology Education Programm. This subject need contextual learning materials and allow in development and progress of science and technology developing. The general problem of student isthe low knowledge in molecular area. One solution for this problem is provide a research-based textbook based on molecular approach. The textbook was developed based on ADDIE development model. The product was validated by instructional media expert, subject matter expert, education practitioner and tested on small group (nine students). Validation results from instructional media expert, subject matter expert, education practitioner, and small group are respectively 87,14%, 91,00%, 75,78%, and 82,22% .Filogenetik molekuler merupakan salah satu kajian yang dipelajari pada matakuliah Evolusi untuk jenjang S1 Pendidikan Biologi. Kajian ini memerlukan bahan ajar yang kontekstual dan tetap mengikuti perkembangan IPTEKS. Kendala yang muncul adalah pengetahuan mahasiswa dalam ranah molekuler masih rendah. Salah satu solusi yang dapat dilakukan adalah dengan menyediakan buku ajar berbasis penelitian denan pendekatan molekuler. Buku ajar dikembangkan berdasarkan model pengembangan ADDIE. Produk divalidasi oleh ahli media, materi, praktisi pendidikan dan diujicobakan pada kelompok kecil. Hasil validasi ahli media, ahli materi, praktisi pendidikan, dan uji coba kelompok kecil secara berturut turut adalah 87,14%, 91,00%, 75,78%, dan 82,22%

    The Dynamics of Good Governance in Promoting Energy Security: The Case of Bangladesh

    Get PDF
    In the modern era, energy and its sustainability have emerged as one of the most important economic issues worldwide. It is widely believed that no country has managed to embrace development without ensuring a sustainable energy supply that could be accessed by a large portion of the population. Thus, this concept of energy sufficiency is of greater importance for the underdeveloped countries those, historically, had not been able to match their local energy demand. Apart from the inefficiencies and resource constraints associated with the energy sector, lack of good governance within an economy is believed to be a critical issue in aggravating energy crisis in those countries. However, following strategic impotence, political unwillingness and inefficient governance of the energy sector, the underdeveloped countries have failed to mitigate the energy deficits which in turn have hampered the development prospects in those countries. This paper highlights the potential roles good governance can play to promote energy security considering the case of Bangladesh, a developing country that is leaving no stones unturned in becoming a middle-income country by 2021. Besides, the role of good governance in complementing fuel diversification as a tool for ensuring energy security has also been put forward. Thus, the government of Bangladesh should reinstate good governance within the economy creating a favourable environment for investment in the energy sector which would enhance competition and mitigate inefficiencies in energy generation, transmission, and distribution

    Potensi Energi Seluler Benih Ikan Lele, Clarias Batrachus L. Pada Berbagai Tingkat Pemberian Pakan Dan Suhu Media

    Get PDF
    Potensi energi seluler yang tersedia untuk metabolisme dalam suatu organisme dapat diukur dari muatan energi adenilat (MEA) yang dihitung dari konsentrasi ATP, ADP dan AMP-nya. Tinggi-rendahnya nilai MEA memiliki korelasi yang sangat penting untuk memantau proses pertumbuhan dari organisme hidup. Tujuan penelitian ini adalah untuk mengetahui keragaman potensi energi seluler (MEA) pada benih ikan lele Clarias batrachus L., sebagai respons terhadap keragaman pemberian pakan berupa Daphnia (dengan tingkat pemberian 0,0; 33,3; 66,7 dan 100% dari kebutuhan pakan harian maksimalnya); masing-masing pada suhu kamar, 20, 24, 28 dan 32oC selama 16 hari. ATP, ADP dan AMP dari masing-masing kelompok perlakuan diekstrasi dan dianalisis dengan metode yang dikembangkan oleh Ivanovicy (1981). Hasil penelitian menunjukkan bahwa peningkatan pemberian pakan disertai dengan peningkatan MEA yang merupakan cerminan potensi energi seluler, dan nilai MEA cenderung menurun dengan meningkatnya suhu. Benih ikan lele dalam kondisi defisiensi nutrisional dengan pertumbuhan negatif mempunyai nilai rata-rata MEA antara 0,47 sampai 0,58, sedangkan benih ikan lele dengan pertumbuhan positif mempunyai nilai rata-rata MEA di atas 0,78

    NESTMOD: The NetMod-NEST Interface

    Full text link
    NESTMOD is a combined analytical modeling and simulation tool, based on the existing tools NetMod and NEST. It provides both transient and steady-state response statistics from models of interconnected local area networks that can execute at any level of detail desired. This gives users the potential to model both networks of extremely large scope (hundreds of thousands of nodes), and to look at great detail for any combination of the ISO layers. This paper describes the interface implementation, and presents an example to illustrate the potential power of the tool.http://deepblue.lib.umich.edu/bitstream/2027.42/107970/1/citi-tr-91-7.pd

    Analisa Bond Index Dalam Penilaian Hasil Penyemenan (Cementing) Production Zone Pada Sumur Rnt-x Lapangan Rantau PT Pertamina Ep Field Rantau, Aceh

    Full text link
    Analisa Bond Index merupakan salah satu metode yang dipakai untuk penilaian hasil penyemenan pada production zone yang berfungsi untuk mengevaluasi nilai bond index pada proses penyemanan. Analisa ini sangat penting sebab apabila didapatkan nilai bond index yang buruk akan mengakibatkan terakumulasinya sejumlah air dalam proses produksi migas di PT Pertamina EP Field Rantau. Tahapan dalam analisa ini meliputi ; menentukan nilai CBL, menentukan nilai attenuation rate, mencari nilai bond index tiap kedalaman, dan menganalisa hasil nilai bond index. Penulis membuat beberapa klasifikasi yang mempengaruhi keberhasilan analisa bond index. Dari klasifikasi ini didapatkan nilai bond index yang baik terdapat pada kedalaman 736 – 738, 713 – 715 , dan 700 – 702 meter, terbentuknya seal hydraulic serta terdapatnya zona isolasi pada bagian top dan bottom zona yang akan diperforasi pada kedalaman 736 – 738, 713 – 715 . Sehingga berdasarkan hasil ini, penilaian analisa Bond Index pada production zone dinilai sudah cukup baik untuk menahan sejumlah air yang akan terakumulasi pada proses produksi migas dan tidak perlu dilakukan cementing ulang

    Pengembangan Buku Ajar Biologi Sel

    Full text link
    Cell biology is one of the biology education studies program\u27s subject in State University of Malang. References used in teaching the Cell Biology course has been no reference based bioinformatics research with the Indonesian language as the language of instruction. The purpose of this study is development of cell biology textbook based on bioinformatic research. The method used Dick and Carey\u27s development method. The results of this study is the product of the textbook-based on virtual screening studies that have been conducted validation specialists (subject matter experts and instructional media expert) with a value of 80% and users with a book value of 89%.Matakuliah Biologi Sel merupakan salah satu matakuliah wajib yang ditempuh oleh mahasiswa tingkat S1 Pendidikan Biologi Universitas Negeri Malang Referensi yang digunakan dalam pembelajaran matakuliah Biologi Sel belum ada referensi yang berbasis penelitian virtual screening dengan bahasa Indonesia sebagai bahasa pengantar. Tujuan penelitian ini yaitu pengembangan buku ajar biologi sel berbasis penelitian bioinformatika. Metode penelitian yang digunakan adalah metode pengembangan Dick and Carey (2009). Hasil penelitian ini yaitu produk berupa buku ajar yang berbasis penelitian virtual screening yang telah dilakukan validasi ahli (ahli materi dan ahli media pembelajaran) dengan nilai 80% dan pengguna buku dengan nilai 89%

    Pengembangan Buku Ajar Biologi Sel Berbasis Bioinformatika

    Full text link
    Cell biology is one of the important subjects in the Department of Biology, with a material very much but the practicum has not been implemented because of limited funding. The solution is to use bioinformatics. Methods used for validation is to use a questionnaire validation to validator matter experts, media experts and validator validator individuals. The results of the validation of subject matter experts is 77,6 with a decent quality aspects categories, media expert is 89,5 with a very decent quality aspects categories and individual validator is 80,6 with a decent quality aspects categories. Therefore, to meet the criteria of an excellent book needs to do some revisions.Biologi sel adalah salah satu matakuliah wajib di Jurusan Biologi, dengan materi yang sangat banyak namun praktikum belum dilaksanakan karena keterbatasan biaya. Solusinya adalah dengan menggunakan bioinformatika. Metode yang dipergunakan untuk validasi adalah dengan menggunakan angket validasi untuk validator ahli materi, validator ahli media dan validator perorangan. Hasil validasi dari ahli materi adalah 77,6 dengan kategori aspek kualitas layak, ahli media adalah 89,5 dengan kategori aspek kualitas sangat layak dan validator perorangan adalah 80,6 dengan kategori aspek kualitas layak. Oleh karena itu, untuk memenuhi kriteria buku yang sangat baik perlu dilakukan beberapa revisi

    Non-Equilibrium Quasiclassical Theory for Josephson Structures

    Full text link
    We present a non-equilibrium quasiclassical formalism suitable for studying linear response ac properties of Josephson junctions. The non-equilibrium self-consistency equations are satisfied, to very good accuracy, already in zeroth iteration. We use the formalism to study ac Josephson effect in a ballistic superconducting point contact. The real and imaginary parts of the ac linear conductance are calculated both analytically (at low frequencies) and numerically (at arbitrary frequency). They show strong temperature, frequency, and phase dependence. Many anomalous properties appear near phi = pi. We ascribe them to the presence of zero energy bound states.Comment: 11 pages, 9 figures, Final version to appear in PR
    corecore