504 research outputs found

    Romanesque and territory. The construction materials of Sardinian medieval churches: new approaches to the valorization, conservation and restoration

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    This paper is intended to illustrate a multidisciplinary research project devoted to the study of the constructive materials of the Romanesque churches in Sardinia during the “Giudicati” period (11th -13th centuries). The project focuses on the relationship between a selection of monuments and their territory, both from a historical-architectural perspective and from a more modern perspective addressing future restoration works. The methodologies of the traditional art-historical research (study of bibliographic, epigraphic and archival sources, formal reading of artifacts) are flanked by new technologies: digital surveys executed with a 3D laser-scanner, analyses of the materials (stones, mortars, bricks) with different instrumental methods: X-ray fluorescence (XRF) and inductively coupled mass spectrometry (ICP-MS) for chemical composition, X-ray diffractometer (XRD) to determine the alteration phases (e.g., soluble salts), optical microscopy and electronic (SEM) to study textures, mineral assemblages and microstructures, termogravimetric/differential scanning, calorimetric analysis (TG/DTA) for the composition of the binder mortars. This multidisciplinary approach allows the achieving of important results in an archaeometric context: 1) from a historical point of view, with the possible identification of ancient traffics, trade routes, sources of raw materials, construction phases, wall textures; 2) from a conservative point of view, by studying chemical and physical weathering processes of stone materials compatible for replacement in case of future restoration works. Sardinian Romanesque architectural heritage is particularly remarkable: about 200 churches of different types and sizes, with the almost exclusive use of cut stones. Bi- or poly-chromy, deriving from the use of different building materials, characterizes many of these monuments, becoming also a vehicle for political and cultural meanings. The paper will present some case studies aimed to illustrate the progress of the project and the results achieved

    On the Hysteretic Behaviour of Wells Turbines

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    The Wells turbine is a self-rectifying axial flow turbine employed in Oscillating Water Column systems to convert low-pressure airflow into mechanical energy. A number of studies highlighted a variation in turbine performance between acceleration and deceleration phases, generally ascribed to the interaction between blade trailing edge vortices and blade boundary layer. This explaination is in opposition with the large existing literature on rapidly pitching airfoils and wings, where it is generally accepted that a hysteretic behavior can be appreciated only at non-dimensional frequencies significantly larger than the ones typically found in Wells turbine. This work presents a critical re-examination of the phenomenon and a new analysis of some of the test cases originally used to explain its origin. The results demonstrate how the behavior of a Wells turbine is not dissimilar to that of an airfoil pitching at very low reduced frequencies and that the causes of the alleged hysteresis are in a different phenomenon

    6-axis inertial sensor using cold-atom interferometry

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    We have developed an atom interferometer providing a full inertial base. This device uses two counter-propagating cold-atom clouds that are launched in strongly curved parabolic trajectories. Three single Raman beam pairs, pulsed in time, are successively applied in three orthogonal directions leading to the measurement of the three axis of rotation and acceleration. In this purpose, we introduce a new atom gyroscope using a butterfly geometry. We discuss the present sensitivity and the possible improvements.Comment: submitted to PR

    PENEGAKAN HUKUM DALAM TINDAK PIDANA PEMERKOSAAN TERHADAP ANAK BERDASARKAN QANUN NOMOR 6 TAHUN 2014 TENTANG HUKUM JINAYAT

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    Qanun Aceh tentang hukum Jinayat merupakan produk fiqh dan telah dirumuskan menjadi hukum positif di Provinsi Aceh. Qanun Jinayat sudah diberlakukan lebih dari satu tahun. Tidak jarang karakteristik khusus Qanun ini memunculkan sejumlah permasalahan yang tidak jarang menyimpang dari ketentuan, misalnya penggunaan istilah asas personalitas, dasar hukum dan materi muatan. Persoalannya adalah tentang bagaimana kedudukan qanun ini didalam sistem hukum nasional, bagaimana keterkaitan antar lembaga penegak hukum dengan lembaga-lembaga yang mendukung dalam pelaksanaan syari’at di Aceh serta apa saja kendala yang dihadapi oleh masing-masing lembaga tersebut serta sampai sejauh mana perlindungan hukum yang diberikan kepada korban tindak pidana perkosaan tersebut.. Dalam kenyataannya bahwa sering terjadi kekerasan seksual yang dialami oleh anak sebagai korban yang dapat terjadi dalam lingkungan kecil yaitu keluarga dan dapat pula terjadi dalam lingkungan masyarakat. Dalam perkara tentang tindak pidana pemerkosaan terhadap anak di Provinsi Nanggroe Aceh Darussalam memiliki sedikit perbedaan dalam prakteknya karena beberapa perkara dapat diterapkan peraturan yang berbeda yaitu dengan menggunakan Undang-undang Perlindungan Anak dan Qanun Jinayat No.6 Tahun 2014. Dari segi hukum formilnya Qanun juga memiliki beberapa kelemahan yang dirasa cukup menghambat proses penegakan hukum yang terjadi di Aceh

    Chronic treatment with long-acting nifedipine reduces vasoconstriction to endothelin-1 in essential hypertension

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    Essential hypertension is associated with enhanced biological activity of endothelin-1 (ET-1) and impaired endothelium-dependent vasodilatation. Dihydropyridine calcium antagonists have antioxidant activity in vitro, and they improve endothelial function in vivo. We tested whether calcium antagonists also influence the biological activity of ET-1 in essential hypertensive (EH) patients in the presence and absence of hypercholesterolemia. In 9 healthy subjects (normotensive [NT] subjects, age: 48.3+/-7.6 years; blood pressure: 118+/-8.6/69+/-5.4 mm Hg) and 21 EH subjects (age: 50.0+/-7.8 years; blood pressure: 164.4+/-5.4/103.8+/-4.4 mm Hg), we studied forearm blood flow and its modification induced by intrabrachial administration of ET-1, phenylephrine, acetylcholine, and sodium nitroprusside at baseline and after 24 weeks of treatment with a nifedipine gastrointestinal therapeutic system (30 to 60 mg per day). At baseline, the first dose of ET-1 (0.5 microg/100 mL of forearm tissue per minute) caused a slight vasodilatation in NT but not in EH subjects, whereas the following higher doses caused a comparable dose-dependent vasoconstriction in EH and NT subjects. The effect of acetylcholine was significantly reduced in EH as compared with NT subjects. In contrast, sodium nitroprusside and phenylephrine had similar effects in NT and EH subjects. After chronic treatment with the nifedipine gastrointestinal therapeutic system, the vasoconstrictor effect induced by both ET-1 and phenylephrine was significantly blunted, whereas the response to acetylcholine was significantly increased and the vasodilation to sodium nitroprusside unchanged. Hypercholesterolemic EH subjects showed a further reduced response to acetylcholine compared with normocholesterolemic EH subjects, and the nifedipine gastrointestinal therapeutic system restored the vasodilation to acetylcholine in this subgroup. In conclusion, in EH subjects, chronic treatment with a long-acting dihydropyridine calcium antagonist not only exhibits a blood pressure-lowering effect but also reduces ET-1-induced vasoconstriction and improves endothelium-dependent vasodilation. Those vasculoprotective effects may importantly contribute to a reduction in major clinical events seen during treatment with these compound

    Mapping a Sex Hormone–Sensitive Gene Determining Female Resistance to Liver Carcinogenesis in a Congenic F344.BN-Hcs4 Rat

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    Hepatocellular carcinoma (HCC) is prevalent in human and rodent males. Hepatocarcinogenesis is controlled by various genes in susceptible F344 and resistant Brown Norway (BN) rats. B alleles at Hcs4 locus, on RNO16, control neoplastic nodule volume. We constructed the F344.BN-Hcs4 recombinant congenic strain (RCS) by introgressing a 4.41-cM portion of Hcs4 from BN strain in an isogenic F344 background. Preneoplastic and neoplastic lesions were induced by the ''resistant hepatocyte'' protocol. Eight weeks after initiation, lesion volume and positivity for proliferating cell nuclear antigen (PCNA) were much higher in lesions of F344 than BN rats of both sexes. These variables were lower in females than in males. Lesion volume and PCNA values of male RCS were similar to those of F344 rats, but in females corresponded to those of BN females. Carcinomatous nodules and HCC developed at 32 and 60 weeks, respectively, in male F344 and congenics and, rarely, in F344 females. BN and congenic females developed only eosinophilic/clear cells nodules. Gonadectomy of congenic males, followed by B-estradiol administration, caused a decrease in Ar expression, an increase in Er-a expression, and development of preneoplastic lesions comparable to those from BN females. Administration of testosterone to gonadectomized females led to Ar increase and development of preneoplastic lesions as in F344 males. This indicates a role of homozygous B alleles at Hcs4 in the determination of phenotypic patterns of female RCS and presence at Hcs4 locus of a high penetrance gene(s), activated by estrogens and inhibited/unaffected by testosterone, conferring resistance to females in which the B alleles provide higher resistance. (Cancer Res 2006; 66(21): 10384-90
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