179 research outputs found

    Digestive alkaline proteases from the Tunisian barbel (Barbus callensis): Characterization and application as a detergent additive, in chicken feather-degradation and as a dehairing agent

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    Alkaline crude enzymes from the viscera of the Tunisian barbel (Barbus callensis) were extracted and characterized. Proteolytic crude extract from barbel viscera was active and stable in alkaline solution. The optimum pH and temperature were 11.0 and 55 °C, respectively, using casein as a substrate. The crude alkaline protease was extremely stable in the pH range of 5.0-12.0. Zymography activity staining using casein as a substrate showed the presence of at least five distinct proteases. The crude alkaline proteases showed stability towards various surfactants, bleach agents and compatibility with some commercial detergents. Alkaline proteases from the viscera of the barbel were tested in chicken feather-degradation and showed important feather degrading activity. Complete solubilisation of whole feathers was observed after 24h of incubation at 50°C. Additionally, crude alkaline protease demonstrated powerful capabilities of hair removal from skin and the collagen, the major leather-forming protein, was not significantly degraded. Considering its promising properties, alkaline crude enzyme from the viscera of the Tunisian barbel may be considered as a potential candidate for future use in several biotechnological processes

    Bounds on positive interior transmission eigenvalues

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    The paper contains lower bounds on the counting function of the positive eigenvalues of the interior transmission problem when the latter is elliptic. In particular, these bounds justify the existence of an infinite set of interior transmission eigenvalues and provide asymptotic estimates from above on the counting function for the large values of the wave number. They also lead to certain important upper estimates on the first few interior transmission eigenvalues. We consider the classical transmission problem as well as the case when the inhomogeneous medium contains an obstacle.Comment: We corrected inaccuracies cost by the wrong sign in the Green formula (17). In particular, the sign in the definition of \sigma was change

    Reconstruction of discontinuous parameters in a second order impedance boundary operator

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    International audienceWe consider the inverse problem of retrieving the coefficients of a second order boundary operator from Cauchy data associated with the Laplace operator at a measurement curve. We study the identifiability and reconstruction in the case of piecewise continuous parameters. We prove in particular the differentiability of the Khon-Vogelius functional with respect to the discontinuity points and employ the result in a gradient type minimizing algorithm. We provide validating numerical results discussing in particular the case of unknown number of discontinuity points

    Determining the shape of defects in non-absorbing inhomogeneous media from far-field measurements

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    International audienceWe consider non-absorbing inhomogeneous media represented by some refraction index. We have developed a method to reconstruct, from far-field measurements, the shape of the areas where the actual index differs from a reference index. Following the principle of the Factorization Method, we present a fast reconstruction algorithm relying on far field measurements and near field values, easily computed from the reference index. Our reconstruction result is illustrated by several numerical test cases

    Feasibility of Using Ultra-High Field (7 T) MRI for Clinical Surgical Targeting

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    The advantages of ultra-high magnetic field (7 Tesla) MRI for basic science research and neuroscience applications have proven invaluable. Structural and functional MR images of the human brain acquired at 7 T exhibit rich information content with potential utility for clinical applications. However, (1) substantial increases in susceptibility artifacts, and (2) geometrical distortions at 7 T would be detrimental for stereotactic surgeries such as deep brain stimulation (DBS), which typically use 1.5 T images for surgical planning. Here, we explore whether these issues can be addressed, making feasible the use of 7 T MRI to guide surgical planning. Twelve patients with Parkinson's disease, candidates for DBS, were scanned on a standard clinical 1.5 T MRI and a 7 T MRI scanner. Qualitative and quantitative assessments of global and regional distortion were evaluated based on anatomical landmarks and transformation matrix values. Our analyses show that distances between identical landmarks on 1.5 T vs. 7 T, in the mid-brain region, were less than one voxel, indicating a successful co-registration between the 1.5 T and 7 T images under these specific imaging parameter sets. On regional analysis, the central part of the brain showed minimal distortion, while inferior and frontal areas exhibited larger distortion due to proximity to air-filled cavities. We conclude that 7 T MR images of the central brain regions have comparable distortions to that observed on a 1.5 T MRI, and that clinical applications targeting structures such as the STN, are feasible with information-rich 7 T imaging

    Strategi Pengaturan Penggunaan Pengeras Suara Masjid/musholla Berbasis Kearifan Lokal

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    Negara Indonesia adalah Negara yang terkenal akan kemajemukan karakteristik masyarakatnya. Termasuk adat istiadat, agama, dan juga etnis atau kesukuan. Hal ini menjadi ciri khas dan keunikan tersendiri yang dimiliki bangsa Indonesia. Sehingga hal tersebut secara tidak langsung menuntut kebijakan publik yang dibuat oleh Pemerintah harus dapat mengakomodasi seluruh kemajemukan tersebut dengan konsep egaliter. Tujuan penulisan artikel ini adalah mengkaji substansi Surat Edaran Menteri Agama Nomor 05 Tahun 2022 Tentang Pedoman Penggunaan Pengeras Suara di Masjid dan Musholla kaitannya dengan implementasi di masyarakat multikultural, dan memberikan gagasan berupa strategi pengaturan pengeras suara masjid atau musholla berbasis kearifan lokal. Jenis penelitian yang digunakan dalam penelitian ini adalah penelitian pustaka (library research) dengan menggunakan metode pendekatan kualitatif, adapun teknis analisis data yang digunakan yakni teknik analisis isi (content analysis). Hasil penelitian artikel ini menyatakan bahwa substansi Surat Edaran Menteri Agama tersebut belum terimplementasi secara maksimal di masyarakat, bahkan menimbulkan polemik, baik itu karena ketidaksetujuan ataupun ketidaktahuan masyarakat mengenai substansi dari kebijakan tersebut. Hal tersebut dapat terjadi karena beberapa faktor diantaranya belum tersosialisasi secara merata, dan bersifat umum. Strategi yang dapat dilakukan yakni pengaturan berbasis kearifan lokal, karena selain mudah diterima juga sejalan dengan prinsip penghargaan terhadap kemajemukan masyarakat

    Mode of failure for reinforced concrete beams with GFRP bars

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    Crack propagation in concrete structures is a very complicated process. An experimental method to predict the stress distribution of a cracked GFRP reinforced concrete flexural beam is presented. The beam subjected to four-point bending is internally reinforced with unidirectional GFRP bars. The aim of this investigation is to study the flexural performance of reinforced concrete members strengthened using GFRP bars. For the flexural tests performed on reinforced concrete beams strengthened with GFRP bars, the ultimate load of the beams strengthened with GFRP was reasonably increased. The mode of failure for beams reinforced with GFRP sections is slightly different compared with the traditional beam. The GFRP reinforced concrete beams fail either by concrete crushing at the compression zone or rupture of the GFRP reinforcement
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