Phonons in MgB2 by Polarized Raman Scattering on Single Crystals

The paper presents detailed Raman scattering study of the unusually broad E2g phonon mode in MgB2 crystal. For the first time, it is shown by the polarized Raman scattering on few-micron-size crystallites with natural faces that the observed broad Raman feature really does obey the selection rules of an E2g mode. Raman spectra on high quality polycrystalline superconducting MgB2 wires reveal a very symmetric E2g phonon line near 615 1/cm with the room temperature linewidth of 260 1/cm only. Additional scattering of different polarization dependence, observed in certain crystallites is interpreted as weighted phonon density of states induced by lattice imperfections.Comment: 4 pages + 7 figure

Penerapan Model Pembelajaran Kooperatif Tipe Tgt (Teams Games Tournament) Dilengkapi Kartu Destinasi Untuk Meningkatkan Kreativitas Dan Hasil Belajar Siswa Pada Materi Pokok Koloid Kelas XI SMA Negeri 2 Sukoharjo

Penelitian ini bertujuan untuk meningkatkan, (1) kreativitas siswa pada materi pokok koloid di SMA Negeri 2 Sukoharjo tahun ajaran 2012/2013 dengan penerapan model pembelajaran kooperatif tipe TGT (Teams Games Tournament) yang dilengkapi kartu destinasi, dan (2) hasil belajar siswa pada materi pokok koloid di SMA Negeri 2 Sukoharjo tahun ajaran 2012/2013 dengan penerapan model pembelajaran kooperatif tipe TGT (Teams Games Tournament) dilengkapi dengan kartu destinasi. Penelitian ini merupakan penelitian tindakan Kelas (PTK) yang terdiri dari dua siklus. Setiap siklus terdiri atas empat tahap yaitu perencanaan, pelaksanaan tindakan, observasi dan refleksi. Subyek penelitian adalah siswa kelas XI IPA 3 SMA Negeri 2 Sukoharjo tahun ajaran 2012/2013. Sumber data berasal dari guru dan siswa. Data diperoleh melalui observasi, wawancara, dokumentasi, tes siklus satu dan dua serta angket. Teknik analisis data yang digunakan adalah analisis deskriptif. Hasil penelitian menunjukkan bahwa, (1) penerapan model pembelajaran kooperatif tipe Teams Games Tournament (TGT) dengan kartu destinasi pada materi pokok koloid dapat meningkatkan kreativitas siswa. Peningkatan kreativitas siswa dapat dilihat dari kenaikan presentase siswa dengan kategori tinggi pada siklus I sebesar 52,94% menjadi 70,59% pada siklus II, (2) penerapan model pembelajaran kooperatif tipe Teams Games Tournament (TGT) dengan kartu destinasi pada materi pokok koloid dapat meningkatkan hasil belajar siswa dari aspek kognitif dan afektif. Pada aspek kognitif ketuntasan siswa pada siklus I 44,12% meningkat menjadi 82,35% pada siklus II. Dari Aspek afektif menunjukkan bahwa terdapat peningkatan persentase dari 74,32% pada siklus I menjadi 80,02% pada siklus II

The nuclear jets in 3C309.1 & 3C380

8 station VLBI maps of the nuclear jets in 3C309.1 and 3C380 reveal complex, bent, structures which seem hard to reconcile with the concept of ballistic outflow. Together with the observation of “flaring” in the MERLIN/EVN map of the 3C309.1 jet the maps point strongly to the jets being confined fluid flows

A progressive diagonalization scheme for the Rabi Hamiltonian

A diagonalization scheme for the Rabi Hamiltonian, which describes a qubit interacting with a single-mode radiation field via a dipole interaction, is proposed. It is shown that the Rabi Hamiltonian can be solved almost exactly using a progressive scheme that involves a finite set of one variable polynomial equations. The scheme is especially efficient for lower part of the spectrum. Some low-lying energy levels of the model with several sets of parameters are calculated and compared to those provided by the recently proposed generalized rotating-wave approximation and full matrix diagonalization.Comment: 8pages, 1 figure, LaTeX. Accepted for publication in J. Phys. B: At. Mol. Opt. Phy

Management of the Brown-Headed Cowbird: Implications for Endangered Species and Agricultural Damage Mitigation

The brown-headed cowbird (Molothrus ater; cowbird) is unique among North American blackbirds (Icteridae) because it is managed to mitigate the negative effects on endangered songbirds and economic losses in agricultural crops. Cowbird brood parasitism can further affect species that are considered threatened or endangered due to anthropogenic land uses. Historically, cowbirds have often been culled without addressing ultimate causes of songbird population declines. Similar to other North American blackbirds, cowbirds depredate agricultural crops, albeit at a lower rate reported for other blackbird species. Conflicting information exists on the extent of agricultural damage caused by cowbirds and the effectiveness of mitigation measures for application to management. In this paper, we reviewed the progress that has been made in cowbird management from approximately 2005 to 2020 in relation to endangered species. We also reviewed losses to the rice (Oryza sativa) crop attributed to cowbirds and the programs designed to reduce depredation. Of the 4 songbird species in which cowbirds have been managed, both the Kirtland’s warbler (Dendroica kirtlandii) and black-capped vireo (Vireo atricapilla) have been removed from the endangered species list following population increases in response to habitat expansion. Cowbird trapping has ceased for Kirtland’s warbler but continues for the vireo. In contrast, least Bell’s vireo (V. bellii pusillus) and southwestern willow flycatcher (Empidonax traillii extimus) still require cowbird control after modest increases in suitable habitat. Our review of rice depredation by cowbirds revealed models that have been created to determine the number of cowbirds that can be taken to decrease rice loss have been useful but require refinement with new data that incorporate cowbird population changes in the rice growing region, dietary preference studies, and current information on population sex ratios and female cowbird egg laying. Once this information has been gathered, bioenergetic and economic models would increase our understanding of the damage caused by cowbirds

Sinteza i biološko vrednovanje novih derivata 2-fenil-benzimidazol-1-acetamida kao potencijalnih anthelmintika

The present study describes synthesis of a series of 2-phenyl benzimidazole-1-acetamide derivatives and their evaluation for anthelmintic activity using Indian adult earthworms, Pheretima posthuma. The structure of the title compounds was elucidated by elemental analysis and spectral data. The compounds 4-({[2-(4-nitrophenyl)-1H-benzimidazol-1-yl]acetyl}amino) benzoic acid (3a), N-ethyl-2-[2-(4-nitrophenyl)-1H-benzimidazol-1-yl] acetamide (3c), N-benzyl-2-[2-(4-nitrophenyl)-1H-benzimidazol-1-yl] acetamide (3d), N-(4-hydroxyphenyl)-2-[2-(4-nitrophenyl)-1H-benzimidazol-1-yl] acetamide (3f), 2-[2-(4-nitrophenyl)-1H-benzimidazol-1-yl]-N-phenylacetamide (3h), 2-[2-(4-chlorophenyl)-1H-benzimidazol-1-yl]-N\u27-phenylacetohydrazide (3k), 2-[2-(4-chlorophenyl)-1H-benzimidazol-1-yl]-N-(4-nitrophenyl) acetamide (3n) and 2-[2-(4-chlorophenyl)-1H-benzimidazol-1-yl]-N-phenylacetamide (3q) were better to paralyze worms whereas N-ethyl-2-[2-(4-nitrophenyl)-1H-benzimidazol-1-yl] acetamide (3c), N-(4-nitrophenyl)-2-[2-(4-nitrophenyl)-1H-benzimidazol-1yl] acetamide (3e), 4-({[2-(4-chlorophenyl)-1H-benzimidazol-1-yl] acetyl} amino) benzoic acid (3j), 2-[2-(4-chlorophenyl)-1H-benzimidazol-1-yl]-N-ethylacetamide (3l) and 2-[2-(4-chlorophenyl)-1H-benzimidazol-1-yl]-N-phenylacetamide (3q) were better to cause death of worms compared to the anthelmintic drug albendazole.U radu je opisana sinteza derivata 2-fenil-benzimidazol-1-acetamida i ispitivanje njihovog anthelmintičkog djelovanja na odrasle indijske gliste, Pheretima posthuma. Struktura sintetiziranih spojeva određena je elementarnom analizom i spektroskopskim metodama. Spojevi 4-({[2-(4-nitrofenil)-1H-benzimidazol-1-il]acetil}amino) benzojeva kiselina (3a), N-etil-2-[2-(4-nitrofenil)-1H-benzimidazol-1-il] acetamid (3c), N-benzil-2-[2-(4-nitrofenil)-1H-benzimidazol-1-il] acetamid (3d), N-(4-hidroksifenil)-2-[2-(4-nitrofenil)-1H-benzimidazol-1-il] acetamid (3f), 2-[2-(4-nitrofenil)-1H-benzimidazol-1-il]-N-fenilacetamid (3h), 2-[2-(4-klorfenil)-1H-benzimidazol-1-il]-N\u27-fenilacetohidrazid (3k), 2-[2-(4-klorfenil)-1H-benzimidazol-1-il]-N-(4-nitrofenil) acetamid (3n) i 2-[2-(4-klorfenil)-1H-benzimidazol-1-il]-N-fenilacetamid (3q) jače paraliziraju gliste, a N-etil-2-[2-(4-nitrofenil)-1H-benzimidazol-1-il] acetamid (3c), 2-[2-(4-nitrofenil)-1H-benzimidazol-1-il]-N-fenilacetamid (3h), 4-({[2-(4-klorfenil)-1H-benzimidazol-1-il]acetil}amino) benzojeva kiselina (3j), 2-[2-(4-klorfenil)-1H-benzimidazol-1-il]-N-etilacetamid (3l) i 2-[2-(4-klorfenil)-1H-benzimidazol-1-il]-N-fenilacetamid (3q) učinkovitije usmrćuju gliste nego anthelmintik albendazol

PENERAPAN MODEL PEMBELAJARAN KOOPERATIF TIPE TGT (TEAMS GAMES TOURNAMENT) DILENGKAPI KARTU DESTINASI UNTUK MENINGKATKAN KREATIVITAS DAN HASIL BELAJAR SISWA PADA MATERI POKOK KOLOID KELAS XI SMA NEGERI 2 SUKOHARJO

Penelitian ini bertujuan untuk meningkatkan, (1) kreativitas siswa pada materi pokok koloid di SMA Negeri 2 Sukoharjo tahun ajaran 2012/2013 dengan penerapan model pembelajaran kooperatif tipe TGT (Teams Games Tournament) yang dilengkapi kartu destinasi, dan (2) hasil belajar siswa pada materi pokok koloid di SMA Negeri 2 Sukoharjo tahun ajaran 2012/2013 dengan penerapan model pembelajaran kooperatif tipe TGT (Teams Games Tournament) dilengkapi dengan kartu destinasi. Penelitian ini merupakan penelitian tindakan Kelas (PTK) yang terdiri dari dua siklus. Setiap siklus terdiri atas empat tahap yaitu perencanaan, pelaksanaan tindakan, observasi dan refleksi. Subyek penelitian adalah siswa kelas XI IPA 3 SMA Negeri 2 Sukoharjo tahun ajaran 2012/2013. Sumber data berasal dari guru dan siswa. Data diperoleh melalui observasi, wawancara, dokumentasi, tes siklus satu dan dua serta angket. Teknik analisis data yang digunakan adalah analisis deskriptif. Hasil penelitian menunjukkan bahwa, (1) penerapan model pembelajaran kooperatif tipe Teams Games Tournament (TGT) dengan kartu destinasi pada materi pokok koloid dapat meningkatkan kreativitas siswa. Peningkatan kreativitas siswa dapat dilihat dari kenaikan presentase siswa dengan kategori tinggi pada siklus I sebesar 52,94% menjadi 70,59% pada siklus II, (2) penerapan model pembelajaran kooperatif tipe Teams Games Tournament (TGT) dengan kartu destinasi pada materi pokok koloid dapat meningkatkan hasil belajar siswa  dari aspek kognitif dan afektif. Pada aspek kognitif ketuntasan siswa pada siklus I 44,12% meningkat menjadi 82,35% pada siklus II. Dari Aspek afektif menunjukkan bahwa terdapat peningkatan persentase dari 74,32% pada siklus I menjadi 80,02% pada siklus II.Kata Kunci: penelitian tindakan kelas, teams games tournament, kartu destinasi, kreativitas, hasil belajar, koloi

Shuffling cards, factoring numbers, and the quantum baker's map

It is pointed out that an exactly solvable permutation operator, viewed as the quantization of cyclic shifts, is useful in constructing a basis in which to study the quantum baker's map, a paradigm system of quantum chaos. In the basis of this operator the eigenfunctions of the quantum baker's map are compressed by factors of around five or more. We show explicitly its connection to an operator that is closely related to the usual quantum baker's map. This permutation operator has interesting connections to the art of shuffling cards as well as to the quantum factoring algorithm of Shor via the quantum order finding one. Hence we point out that this well-known quantum algorithm makes crucial use of a quantum chaotic operator, or at least one that is close to the quantization of the left-shift, a closeness that we also explore quantitatively.Comment: 12 pgs. Substantially elaborated version, including a new route to the quantum bakers map. To appear in J. Phys.

Generalized Entanglement as a Natural Framework for Exploring Quantum Chaos

We demonstrate that generalized entanglement [Barnum {\em et al.}, Phys. Rev. A {\bf 68}, 032308 (2003)] provides a natural and reliable indicator of quantum chaotic behavior. Since generalized entanglement depends directly on a choice of preferred observables, exploring how generalized entanglement increases under dynamical evolution is possible without invoking an auxiliary coupled system or decomposing the system into arbitrary subsystems. We find that, in the chaotic regime, the long-time saturation value of generalized entanglement agrees with random matrix theory predictions. For our system, we provide physical intuition into generalized entanglement within a single system by invoking the notion of extent of a state. The latter, in turn, is related to other signatures of quantum chaos.Comment: clarified and expanded version accepted by Europhys. Let

Spin-Boson Hamiltonian and Optical Absorption of Molecular Dimers

An analysis of the eigenstates of a symmetry-broken spin-boson Hamiltonian is performed by computing Bloch and Husimi projections. The eigenstate analysis is combined with the calculation of absorption bands of asymmetric dimer configurations constituted by monomers with nonidentical excitation energies and optical transition matrix elements. Absorption bands with regular and irregular fine structures are obtained and related to the transition from the coexistence to a mixing of adiabatic branches in the spectrum. It is shown that correlations between spin states allow for an interpolation between absorption bands for different optical asymmetries.Comment: 15 pages, revTeX, 8 figures, accepted for publication in Phys. Rev.