2,004 research outputs found

    Evidence for the Validity of the Berry-Robnik Surmise in a Periodically Pulsed Spin System

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    We study the statistical properties of the spectrum of a quantum dynamical system whose classical counterpart has a mixed phase space structure consisting of two regular regions separated by a chaotical one. We make use of a simple symmetry of the system to separate the eigenstates of the time-evolution operator into two classes in agreement with the Percival classification scheme \cite{Per}. We then use a method firstly developed by Bohigas et. al. \cite{BoUlTo} to evaluate the fractional measure of states belonging to the regular class, and finally present the level spacings statistics for each class which confirm the validity of the Berry-Robnik surmise in our model.Comment: 15 pages, 9 figures available upon request, Latex fil

    Comparison of numerical and experimental strains distributions in composite panel for aerospace applications

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    In structural applications of aerospace industry, weight efficiency, understood as minimal weight and maximal stiffness, is of great importance. This criterion can be achieved by composite lightweight structures. Typical structures for aforementioned applications are sandwich panels (e.g., with honeycomb core) and stiffened panels (e.g., with blade ribs, T-bar ribs, or hat ribs). In this paper, a hat-stiffened panel, made of carbon/epoxy woven composite, is considered. Results of experiments, consisting of loading the panel and measuring exciting forces and strains (using strain gages), are presented. The results are compared to strains distribution obtained from finite element model of the panel.The research was partially funded from financial resources from the statutory subsidy of the Faculty of Mechanical Engineering, Silesian University of Technology, in 2021. W.M. acknowledges the National Agency for Academic Exchange of Poland (under the Academic International Partnerships program, grant agreement PPI/APM/2018/1/00004) for supporting training in the University of Minho, which enabled execution of the study

    Pengaruh Pemberian Dua Jenis Mulsa Dan Tanpa Mulsa Terhadap Karakteristik Pertumbuhan Dan Produksi Tanaman Cabai Merah (Capsicum Annum L) Pada Dataran Rendah

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    Cabai (Capsicum annuum L.) merupakan komoditas sayuran yang mempunyai prospek cerah untuk dapat dikembangkan. Permintaan produk cabai cenderung terus meningkat. Nilai ekonomi yang tinggi merupakan daya tarik pengembangan budidaya cabai bagi petani. Untuk memenuhi permintaan pasar yang semakin meningkat dan pemenuhan gizi masyarakat, banyak USAha yang dapat dilakukan guna peningkatan produksi cabai merah yang tinggi. Salah satu USAha yang dapat dilakukan adalah melakukan teknik budidaya yang baik dan benar sehingga hasil yang diperoleh optimal. Penelitian ini bertujuan untuk: (1) mengetahui pengaruh pemberian dua jenis mulsa dan tanpa mulsa terhadap karakteristik pertumbuhan dan produksi tanaman cabai merah, (2) mengetahui jenis mulsa yang menghasilkan karakteristik pertumbuhan dan produksi tanaman cabai merah yang terbaik. Penelitian ini dilaksanakan di Desa Suka Banjar, Gedong Tataan pada bulan Oktober 2011– April 2012. Penelitian ini disusun dengan menggunakan rancangan acak kelompok (RAK) dengan tiga perlakuan (tanpa mulsa, mulsa plastik, mulsa jerami) dan tiga ulangan. Homogenitas ragam diuji dengan uji Bartlett. Jika asumsi terpenuhi, dilanjutkan dengan sidik ragam dan apabila hasil uji F nyata maka dilakukan uji lanjut menggunakan uji ortogonal kontras pada taraf 5. Hasil penelitian menunjukkan bahwa: (1)Pemberian mulsa plastik hitam perak dan jerami menunjukkan pengaruh terhadap karakteristik tanaman cabai yang berbeda dibandingkan tanpa mulsa, yaitu pada variabel tinggi tanaman dan tingkat percabangan, (2 Penggunaan mulsa plastik lebih baik daripada mulsa jerami untuk produksi tanaman cabai

    Fidelity Decay as an Efficient Indicator of Quantum Chaos

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    Recent work has connected the type of fidelity decay in perturbed quantum models to the presence of chaos in the associated classical models. We demonstrate that a system's rate of fidelity decay under repeated perturbations may be measured efficiently on a quantum information processor, and analyze the conditions under which this indicator is a reliable probe of quantum chaos and related statistical properties of the unperturbed system. The type and rate of the decay are not dependent on the eigenvalue statistics of the unperturbed system, but depend on the system's eigenvector statistics in the eigenbasis of the perturbation operator. For random eigenvector statistics the decay is exponential with a rate fixed precisely by the variance of the perturbation's energy spectrum. Hence, even classically regular models can exhibit an exponential fidelity decay under generic quantum perturbations. These results clarify which perturbations can distinguish classically regular and chaotic quantum systems.Comment: 4 pages, 3 figures, LaTeX; published version (revised introduction and discussion

    International Classification of Functioning, Disability and Health: Development of an assessment set to evaluate functioning based on the Brief ICF Core Set for Hand Conditions - ICF HandA

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    Timely identification of patients' problems after disorder or injury of the hand requires a thorough functional assessment. However, the variety of outcome measures available makes it difficult to choose the appropriate instrument. The brief International Classification of Functioning, Disability and Health (Brief ICF Core Set for Hand Conditions) provides a standard for what aspects need to be measured in hand injuries and disorders without specifying how to make the assessment. We developed the ICF-based Assessment Hand (ICF HandA), an assessment set for functioning based on the Brief ICF Core Set for Hand Conditions. First, we performed a literature review and an expert survey to pool outcome measures appropriate to assess functioning in clinical practice. At an interdisciplinary consensus conference experts decided on the outcome measures to be included in the ICF HandA. The ICF HandA provides a consensus on outcome measures and instruments to systematically assess function in patients with hand injuries and disorders

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

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    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

    Generalized Entanglement as a Natural Framework for Exploring Quantum Chaos

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    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
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