Symmetry characterization of the collective modes of the phase diagram of the ν=0\nu=0 quantum Hall state in graphene: Mean-field and spontaneously broken symmetries

We devote this work to the study of the mean-field phase diagram of the $\nu=0$ quantum Hall state in bilayer graphene and the computation of the corresponding neutral collective modes, extending the results of recent works in the literature. Specifically, we provide a detailed classification of the complete orbital-valley-spin structure of the collective modes and show that phase transitions are characterized by singlet modes in orbital pseudospin, which are independent of the Coulomb strength and suffer strong many-body corrections from short-range interactions at low momentum. We describe the symmetry breaking mechanism for phase transitions in terms of the valley-spin structure of the Goldstone modes. For the remaining phase boundaries, we prove that the associated exact $SO(5)$ symmetry existing at zero Zeeman energy and interlayer voltage survives as a weaker mean-field symmetry of the Hartree-Fock equations. We extend the previous results for bilayer graphene to the monolayer scenario. Finally, we show that taking into account Landau level mixing through screening does not modify the physical picture explained above.Comment: 44 pages, 10 figure

ETNOZOLOOGI UNTUK RITUAL ADAT MASYARAKAT DAYAK KANAYATN DI DESA ANTAN RAYAN KECAMATAN NGABANG KABUPATEN LANDAK

The people of Kalimantan from various tribes use animals for their daily needs such as consumption needs, traditional rituals, medicine, decoration, supernatural and commercial activities, equipment and others. One of the indigenous tribes in West Kalimantan is the Kanayatn Dayak tribe located in Antan Rayan Village, Ngabang District, Landak Regency. The use of animals by the Kanayatn Dayak Community has become a hereditary culture from their ancestors. The purpose of this study was to record the types of animals used for traditional rituals and how to use them by the Kanayatn Dayak community. This study uses data collection methods, namely by field surveys, interviews and direct observations in the field, for data collection by snowball sampling technique, namely by determining respondents to then determine other respondents based on information from previous respondents, and so on. The results showed that the number of animals used for traditional rituals by the Kanayatn Dayak people in Antan Rayan Village, Ngabang District, Landak Regency, were 16 species of animals from 11 families. Animal parts used for traditional rituals are the whole body, head, blood, feathers, bile, and oil. The main customs that must be used by the Kanayant Dayak community are pork, free-range chicken, palm wine, and flour with the distribution of rice mixed with chicken blood. Keywords: Ritual Custom, Kanayatn Dayak, EthnozoologyAbstrakMasyarakat Kalimantan dari berbagai suku menggunakan hewan untuk kebutuhan sehari-hari seperti kebutuhan konsumsi, ritual adat, obat-obatan, dekorasi, kegiatan supranatural dan komersial, peralatan dan lain-lain. Salah satu suku asli di Kalimantan Barat adalah Suku Dayak Kanayatn yang terletak di Desa Antan Rayan, Kecamatan Ngabang, Kabupaten Landak. Pemanfaatan satwa oleh Masyarakat Dayak Kanayatn sudah menjadi budaya turun temurun dari nenek moyang mereka. Tujuan dari penelitian ini adalah untuk mendata jenis-jenis satwa yang digunakan untuk ritual adat dan cara pemanfaatannya oleh masyarakat Dayak Kanayatn. Penelitian ini menggunakan metode pengumpulan data yaitu dengan cara survey lapangan, wawancara dan observasi langsung di lapangan, untuk pengumpulan data dengan teknik snowball sampling yaitu dengan cara menentukan responden untuk kemudian menentukan responden lain berdasarkan informasi dari responden sebelumnya, dan seterusnya. Hasil penelitian menunjukkan bahwa jumlah satwa yang digunakan untuk ritual adat oleh masyarakat Dayak Kanayatn di Desa Antan Rayan Kecamatan Ngabang Kabupaten Landak sebanyak             16 jenis satwa dari 11 famili. Bagian satwa yang digunakan untuk ritual adat adalah seluruh tubuh, kepala, darah, bulu, empedu, dan minyak. Adat pokok yang wajib digunakan oleh masyarakat Dayak Kanayant adalah babi, ayam kampung, tuak, dan tepung dengan pembagian nasi campur darah ayam.  Kata Kunci: Ritual Adat, Dayak Kanayatn, Etnozoolog

Violation of Cauchy-Schwarz inequalities by spontaneous Hawking radiation in resonant boson structures

The violation of a classical Cauchy-Schwarz (CS) inequality is identified as an unequivocal signature of spontaneous Hawking radiation in sonic black holes. This violation can be particularly large near the peaks in the radiation spectrum emitted from a resonant boson structure forming a sonic horizon. As a function of the frequency-dependent Hawking radiation intensity, we analyze the degree of CS violation and the maximum violation temperature for a double barrier structure separating two regions of subsonic and supersonic condensate flow. We also consider the case where the resonant sonic horizon is produced by a space-dependent contact interaction. In some cases, CS violation can be observed by direct atom counting in a time-of-flight experiment. We show that near the conventional zero-frequency radiation peak, the decisive CS violation cannot occur.Comment: 10 pages, 6 figure

Leaching of Oil from Tuna Fish Liver by Using Solvent of Methyl-Ethyl Ketone

Research of oil leaching from Tuna Fish Liver has been carried out by extracting of tuna fish liver in soxhlet by using methyl-ethyl ketone as solvent. Liver of fresh tuna fish is blended, put into soxhlet, and extracted at temperatures of 60oC, 65oC, 70oC, 75oC, and 80oC. After obtaining the oil, separation between solvent and oil is carried out by distillation. Oil obtained is analyzed by testing the yield, acid number, Iodine value, viscosity, and its impurities content. Yield obtained is influenced by temperature and time of leaching. Both variables indicates that the higher the variables, the more fish liver oil obtained. Maximum yield obtained is 25.552% at operating condition of leaching temperature 80oC, and leaching duration of 5 hours

O impacte da orientação nas comunidades vegetais – O caso do Grande Prémio de Orientação de Terras do Bouro

Na sociedade atual os hábitos de desporto e lazer viram-se cada vez mais para a utilização do meio natural para a sua prática, como é o caso da Orientação. O impacte da orientação no ambiente tem duas facetas, por um lado a degradação da sua qualidade, através dos resíduos que são deixados inadvertidamente nas áreas onde se realizam as provas, por outro lado na destruição de vegetação e perturbação de espécies de animais. Ambas as categorias de impactes podem ser minimizadas desde que se cumpram um conjunto de regras de boas práticas ambientais. O estudo em causa teve como objectivos a avaliação do impacte do Grande Prémio de Orientação de Terras do Bouro sobre a flora e vegetação da serra de Santa Isabel, e da sua capacidade de regeneração subsequente ao evento. Este evento realizou-se nos dias 11 e 12 de Novembro de 2006, e consistiu numa prova da Taça de Portugal de Orientação Pedestre. A primeira etapa correspondeu a uma prova de distância média e a segunda etapa a uma prova de distância longa. Com este trabalho pretende-se contribuir para um melhor conhecimento dos impactes originados pela realização de provas de orientação sobre a vegetação, de forma a fornecer informação que possibilite uma melhor gestão ambiental deste tipo de eventos desportivos.FPO - Federação Portuguesa de Orientação. FCT – Fundação para a Ciência e a Tecnologia no âmbito do projecto PEst-OE/AGR/UI0681/2011