28 research outputs found

    Synergistic and Interdisciplinary Approaches for the Conservation of Monumental Heritage: Cupola of Santa Maria del Fiore in Florence, Italy

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    This paper presents the results of an interdisciplinary study carried out on Brunelleschi’s Cupola of Santa Maria del Fiore in Florence, Italy, one of the most emblematic masonry domes in the world. The cupola has been affected since the beginning of its construction by a widespread cracking phenomenon, and several studies were done over the centuries to clarify its safety conditions. To have a direct and indirect record of the cracks opening or closing, a complex monitoring system was installed on the monument during the last century. An accurate analysis of crack widths and global displacements, performed considering both historical and recent monitoring data, has allowed for the identification of the movements developed in the monument, evaluating their relationship with environmental and seismic events. In line with the interdisciplinary approach strongly recommended in the field of assessment and conservation of monumental heritage, this paper reconsiders some issues concerning the causes of the actual damage to the cupola. In particular, in light of the obtained results, the famous seventeenth century Viviani’s conclusions about the cupola’s damage, confirmed by Chiarugi in the 1980s, are compared with other hypotheses, such as the differential settlement of pillars (Cecchini in 1698 and Ximenes in 1757) and the influence of temperature variations (Nervi in 1934). The large amount of measured data and the results of the last numerical models of the cupola, combined with recent dynamic measurements, allowed the updating of some previous conclusions on damage causes and trends. Starting from these conclusions, a more reliable forecasting model of the monument can be set up that could be useful in identifying effective conservation strategy for this outstanding monument

    Spontaneous polarization and piezoelectric field in G a N / A l 0.15 Ga 0.85 N quantum wells: Impact on the optical spectra

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    We have investigated the effects of the built-in electric field in GaN/Al0.15Ga0.85N{\mathrm{G}\mathrm{a}\mathrm{N}/\mathrm{A}\mathrm{l}}_{0.15}{\mathrm{Ga}}_{0.85}\mathrm{N} quantum wells by photoluminescence spectroscopy. The fundamental electron heavy-hole transition redshifts well below the GaN bulk gap for well widths larger than 3 nm for the specific quantum wells investigated and exhibits a concomitant reduction of the intensity with increasing well thickness. The experimental data are quantitatively explained by means of a self-consistent tight-binding model that includes screening (either dielectric or by free-carriers), piezoelectric field and spontaneous polarization field. The impact of the built-in field on the exciton stability is discussed in detail. We demonstrate that the exciton binding energy is substantially reduced by the built-in field, well below the values expected from the quantum size effect in the flat band condition

    Model Numerikal Reservoir Sistem Panasbumi Pada Daerah Topografi Relatif Datar Untuk Mencari Kondisi Natural State Dan Menganalisa Sensitivitas Panas Pada Reservoir Menggunakan Software Tough2

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    Telah dilakukan pemodelan reservoir menggunakan software Tough2 dengan data sintetik, berupa data permeabilitas dan pororsitas. Dimana terdiri dari 4 lapisan, yaitu lapisan overburden, lapisan clay caps, lapisan recharge area + lapisan reservoir (berada pada lapisan yang sama), dan lapisan basement dengan tujuan untuk menganalisa sensitivitas panas, serta untuk mencari kondisi natural state (natural state merupakan kondisi setimbang, yaitu dimana kondisi tekanan, temperatur dan kondisi reservoirnya tidak berubah terhadap waktu).Dari hasil pemodelan reservoir oleh Tough2 didapat bahwa kondisi natural state selama 2,20857E+4 tahun, dimana terjadi penurunan suhu dari kondisi natural state tanpa sumur produksi berbanding kondisi natural state dengan sumur produksi, dimana suhu pada saat kondisi natural state tanpa sumur produksi sebesar 245OC dan suhu pada saat kondisi natural state dengan sumur produksi sebesar 235OC pada kedalaman 1350 m. Sedangkan untuk penggunaan rate 20 kg/s, 25 kg/s, 30 kg/s dan 35 kg/s untuk melihat sensitivitas heat nya, didapatkan bahwa semakin besar nilai rate yang dipakai dalam suatu sumur produksi, maka akan menurunnya nilai temperatur di sumur produksi tersebut

    Biochemical and mass spectrometric characterization of soluble ecto-5'-nucleotidase from bull seminal plasma.

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    Ecto-5'-nucleotidase (ecto-5'-NT) is a glycosylphosphatidylinositol-anchored membrane-bound protein that is ubiquitous in mammalian tissues. It is a target for a number of therapeutic drugs since increased levels of the enzyme correlate with various disease states. In this investigation, we describe the properties of a soluble ecto-5'-NT derived from bull seminal plasma. The protein was highly heterogeneous as demonstrated by chromatofocusing and two-dimensional PAGE. Sequencing analyses revealed a truncated polypeptide lacking the glycosylphospatidylinositol attachment site, suggesting that it is produced post-translationally by cleavage at Gln(547) and/or Phe(548). Heterogeneity was largely due to differential glycosylation, especially in the oligosaccharides linked to Asn(403). Significant differences in substrate specificity were observed between isoforms and, on the basis of molecular-modelling studies, were interpreted in terms of variable glycosylation causing steric hindrance of the substrate-binding site. Thus the soluble forms of ecto-5'-NT found in bull seminal plasma are unique both biochemically and structurally, and have a putative role in signalling interactions with spermatozoa following ejaculation and capacitation in the female reproductive tract

    Unveiling Hidden Prints: Optically stimulated luminescence for latent fingerprint detection

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    Fluorescent lighting and optical techniques have been widely utilized to enhance the detection of latent fingerprints. However, the development of new techniques is imperative to expand the range of surfaces from which latent fingerprints can be detected. When relying on traditional methods, fingerprint evidence can remain undetected or even disregarded due to insufficient detection and limited detail, especially when dealing with a luminescent background.In this study, we propose the utilization of optically stimulated luminescence (OSL) applied to a Ba2SiO4 matrix, co-doped with Eu2+ and Dy3+, as a powerful method for visualizing latent fingerprints on various surfaces, including thin plastic bags, rigid duct tape, thin aluminum foil, and glass slices. This technique effectively eliminates any luminescent background and significantly enhances optical imaging.This represents the first successful application of OSL in the development of latent fingerprints, thus paving the way for more efficient and effective forensic techniques in the future

    Effect of sentinel node biopsy in clinically N0, BRAF V600E-mutated, small papillary thyroid carcinoma: A pilot study.

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    PURPOSE: BRAF V600E mutation papillary thyroid cancer (PTC) is more aggressive with a higher risk of lymph node involvement and a poorer prognosis. Prior studies failed to demonstrate the superiority of prophylactic lymphadenectomy. We investigated the utility of additional radio-guided sentinel node biopsy (SNB). METHODS: We analyzed 15 patients with N0 PTC by ultrasound and BRAF mutation on preoperative biopsy treated with total thyroidectomy (TT) or TT + prophylactic central neck dissection (PCND) alone or with SNB. Conventional surgery was performed before SNB. We recorded primary tumor diameter, multifocality, extrathyroid infiltration, neoplastic emboli, and tall cell variant. At follow-up, we evaluated basal and stimulated thyroglobulin and ultrasound or radioiodine scintigraphy. RESULTS: Of 15 consecutive patients, 5 received conventional surgery alone, and 10 had SNB. For the first group, 4 underwent TT, and 1 had TT + PCND. Among the SNB group, 1 had no sentinel node detected and underwent a simple TT, 2 had TT + PCND+ SNB in the lateral compartment, and 7 had TT + SNB in 1 to 3 neck compartments. Micrometastases were found in 1 of 3 PCND specimens. Sentinel node biopsy revealed metastasis in 3 of 6 central compartment biopsies, in 2 of 6 biopsies in the ipsilateral lateral compartment, and in none of 2 biopsies in the contralateral compartment. Sentinel node biopsy allowed the removal of micrometastases in 4 of 10 patients. At 53 months' (mean) follow-up, no relapse was documented. CONCLUSIONS: Radio-guided SNB correctly and efficiently stages cN0 BRAF-mutated PTC patients. Sentinel node biopsy could limit time-consuming, risk-exposing compartmental prophylactic dissections
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