735 research outputs found

    Theory of magnetic field-induced metaelectric critical end point in BiMn2_2O5_5

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    A recent experiment on the multiferroic BiMn2_2O5_5 compound under a strong applied magnetic field revealed a rich phase diagram driven by the coupling of magnetic and charge (dipolar) degrees of freedom. Based on the exchange-striction mechanism, we propose here a theoretical model with the intent to capture the interplay of the spin and dipolar moments in the presence of a magnetic field in BiMn2_2O5_5. Experimentally observed behavior of the dielectric constants, magnetic susceptibility, and the polarization is, for the most part, reproduced by our model. The critical behavior observed near the polarization reversal (P=0)(P=0) point in the phase diagram is interpreted as arising from the proximity to the critical end point.Comment: Theory; relevant experiment uploaded as arXiv:0810.190

    Desain Implementasi Material Handling Equipment Untuk Distribusi Bahan Dan Produk Pada Industri

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    Dalam proses industri manufaktur, bahan baku atau produk perlu dipindahkan dari satu titik ke titik lainnya dengan jarak tertentu dan dipilah antara produk satu dan produk lainnya. .Proses pemindahan dan pemilahan barang pada industri dengan menggunakan konveyor yang bekerja untuk mengangkut material dari satu titik ke titik lainnya, konveyor yang digunakan saat ini masih memiliki beberapa kelemahan seperti tidak dapat mengukur berat produk, tidak dapat menyortir produk berdasarkan bentuk, tidak dapat mendeteksi jenis benda dan tidak dapat mengatur kecepatan motor. Dengan tujuan untuk memperoleh hasil produksi yang maksimal, diperlukan sistem Material handling equipment yang baik dalam proses distribusi suatu barang. Oleh karena itu penulis melakukan penelitian sistem otomasi pada konveyor menggunakan mikrokontroller dengan beberapa sensor seperti sensor proximity, sensor photodioda, sensor loadcell dan sensor ultrasoni . Sistem yang dibuat dapat membantu menyelesaikan permasalahan yang ada di industri yaitu dapat mengembangkan sistem automation conveyor yang cepat, aman dan efisien. Hal ini bertujuan untuk mengurangi intervensi manusia sekaligus meningkatkan produktivitas Perusahaan

    Efficient determination of cysteine sulphoxides in Allium plants applying new biosensor and HPLC-MS² methods

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    Cysteine sulphoxide (CSO) contents of 16 different accessions of garlic (Allium sativum L.) and 15 varieties of onion (Allium cepa L.) were measured using two different rapid analytical methods: a biosensoric approach and a newly developed HPLC-MS2 technique. Both methods allow quantification of naturally occurring cysteine sulphoxides present in Allium plants without time-consuming sample pretreatment such as derivatisation of amino acid derivatives prior to HPLC-separation. It has been found that the amount of alliin, which is the predominant CSO occurring in garlic, varies between 0.2 and 2.2 g/100 g dry matter. Contrary to that, isoalliin representing the main CSO in onion has been detected in significantly lower amounts (0.3 to 1.25 g/100 g dry matter)

    Autonomous stochastic resonance in fully frustrated Josephson-junction ladders

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    We investigate autonomous stochastic resonance in fully frustrated Josephson-junction ladders, which are driven by uniform constant currents. At zero temperature large currents induce oscillations between the two ground states, while for small currents the lattice potential forces the system to remain in one of the two states. At finite temperatures, on the other hand, oscillations between the two states develop even below the critical current; the signal-to-noise ratio is found to display array-enhanced stochastic resonance. It is suggested that such behavior may be observed experimentally through the measurement of the staggered voltage.Comment: 6 pages, 11 figures, to be published in Phys. Rev.

    Quantum and frustration effects on fluctuations of the inverse compressibility in two-dimensional Coulomb glasses

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    We consider interacting electrons in a two-dimensional quantum Coulomb glass and investigate by means of the Hartree-Fock approximation the combined effects of the electron-electron interaction and the transverse magnetic field on fluctuations of the inverse compressibility. Preceding systematic study of the system in the absence of the magnetic field identifies the source of the fluctuations, interplay of disorder and interaction, and effects of hopping. Revealed in sufficiently clean samples with strong interactions is an unusual right-biased distribution of the inverse compressibility, which is neither of the Gaussian nor of the Wigner-Dyson type. While in most cases weak magnetic fields tend to suppress fluctuations, in relatively clean samples with weak interactions fluctuations are found to grow with the magnetic field. This is attributed to the localization properties of the electron states, which may be measured by the participation ratio and the inverse participation number. It is also observed that at the frustration where the Fermi level is degenerate, localization or modulation of electrons is enhanced, raising fluctuations. Strong frustration in general suppresses effects of the interaction on the inverse compressibility and on the configuration of electrons.Comment: 15 pages, 18 figures, To appear in Phys. Rev.

    Ethical aspects of registry-based research in the Nordic countries

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    National health care registries in the Nordic countries share many attributes, but different legal and ethical frameworks represent a challenge to promoting effective joint research. Internationally, there is a lack of knowledge about how ethical matters are considered in Nordic registry-based research, and a lack of knowledge about how Nordic ethics committees operate and what is needed to obtain an approval. In this paper, we review ethical aspects of registry-based research, the legal framework, the role of ethics review boards in the Nordic countries, and the structure of the ethics application. We discuss the role of informed consent in registry-based research and how to safeguard the integrity of study participants, including vulnerable subjects and children. Our review also provides information on the different government agencies that contribute registry-based data, and a list of the major health registries in Denmark, Finland, Iceland, Norway, and Sweden. Both ethical values and conditions for registry-based research are similar in the Nordic countries. While Denmark, Finland, Iceland, Norway, and Sweden have chosen different legal frameworks, these differences can be resolved through mutual recognition of ethical applications and by harmonizing the different systems, likely leading to increased collaboration and enlarged studies

    The Impacts of Deep Surgical Site Infections on Readmissions, Length of Stay, and Costs:A Matched Case-Control Study Conducted in an Academic Hospital in the Netherlands

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    Objective: This study aimed to evaluate the impacts of deep surgical site infections (dSSIs) regarding hospital readmissions, prolonged length of stay (LoS), and estimated costs. Patients and Methods: We designed and applied a matched case–control observational study using the electronic health records at the University Medical Center Groningen in the Netherlands. We compared patients with dSSI and non-SSI, matched on the basis of having similar procedures. A prevailing topology of surgeries categorized as clean, clean-contami-nated, contaminated, and dirty was applied. Results: Out of a total of 12,285 patients, 393 dSSI were identified as cases, and 2864 patients without SSIs were selected as controls. A total of 343 dSSI patients (87%) and 2307 (81%) controls required hospital readmissions. The median LoS was 7 days (P25-P75: 2.5–14.5) for dSSI patients and 5 days (P25-P75: 1–9) for controls (p-value: <0.001). The estimated mean cost per hospital admission was €9,016 (SE±343) for dSSI patients and €5,409 (SE±120) for controls (p<0.001). Independent variables associated with dSSI were patient’s age ≥65 years (OR: 1.334; 95% CI: 1.036–1.720), the use of prophylactic antibiotics (OR: 0.424; 95% CI: 0.344–0.537), and neoplasms (OR: 2.050; 95% CI: 1.473–2.854). Conclusion: dSSI is associated with increased costs, prolonged LoS, and increased read-mission rates. Elevated risks were seen for elderly patients and those with neoplasms. Additionally, a protective effect of prophylactic antibiotics was found

    Extracardiac Fontan with T-shape conduit in non-confluent pulmonary arteries

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    A 34 months-old male patient with double inlet right ventricle with nonconfluent pulmonary arteries who underwent successful extracardiac fenestarated Fontan procedure using pre-designed T-shaped PTFE vascular graft after multi-step rehabilitation of the diminutive hilar pulmonary arteries. At first we performed 6 mm confluent pulmonary artery vascular graft implantation with 4 mm BT shunt at patient's 4 weeks old. At 9 months of patient, we upsized the confluent pulmonary arterial graft to 8 mm with bidirectional cavopulmonary connection, and, at 34 months, we performed extracardiac conduit Fontan procedure with pre-designed T-shape conduit including the confluent pulmonary arterial portion at last. Patient shows excellent functional status and development
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