Search results for "shell"
showing 10 items of 748 documents
Ribotyping of Vibrio Populations Associated with Cultured Oysters (Ostrea edulis)
2000
The intraspecific variability of Vibrio splendidus, V. harveyi and V. tubiashii recovered from oysters (Ostrea edulis) collected at the Mediterranean coast near Valencia, Spain, was analyzed by ribotyping. The two former species represented the most abundant ones, and the third one was the only species described as pathogenic for oysters. A total of 115 environmental strains were studied, 84 of V. splendidus, 23 of V. harveyi and 8 of V. tubiashii. Chromosomal DNA was digested with KpnI and hybridized with an oligonucleotide probe complementary to a highly conserved sequence in the 23S rRNA gene. Ribotyping among natural populations of the three species rendered 5 to 9 bands, and showed a h…
Assessment of Salmonella spp. in feces, cloacal swabs, and eggs (eggshell and content separately) from a laying hen farm.
2011
Microbial pathogens of the genus Salmonella are among the leading causes of foodborne illness in the world. The present study was done on a laying hen farm with a Salmonella enterica serovar Enteritidis-positive result according to the testing specified by European regulation 2160/2003. The aim of this study was to compare the Salmonella contamination on a laying hen farm with the Salmonella presence in the hen eggs. The strains were isolated by ISO method 6579:2002 (standard method for the detection of Salmonella spp. in the European regulation for food and animal feeding stuffs, animal feces, and environmental samples from the primary production stage, including poultry farms) and were co…
Molecular and supramolecular structures of self-assembled Cu(II) and Co(II) complexes with 4,4’-[6-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazine-2,4-…
2020
Abstract The molecular and supramolecular structures of [Cu(PTM)Cl2]∗0.75MeOH (1), [Co(PTM)Cl2]; (2A) and [Co(PTM)Cl2(EtOH)]; (2B) complexes, where PTM is 4,4’-[6-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazine-2,4-diyl]dimorpholine, were presented. In complexes 1 and 2A, the Cu(II) and Co(II) are tetra-coordinated with a distorted tetrahedral coordination environment. In case of complex 2B, an additional ethanol molecule is found coordinated with Co(II) leading to a highly distorted penta-coordinated Co(II) complex. In all cases, the PTM ligand is acting as a bidentate NN-chelate. Hirshfeld surface analysis indicated the importance of H⋯H (49.0–55.1%), Cl⋯H (18.8–20.5%) and O⋯H (8.3–9.9%) co…
Preparation of Hg2+ selective fluorescent chemosensors based on surface modified core–shell aluminosilicate nanoparticles
2010
A synthetic procedure for the preparation of functional structured inorganic–organic hybrid materials consisting of boehmite-silica core–shell nanoparticles and anthracene-containing amines covalently attached to the nanoparticles surface is reported. The system functionalised with the monoamine chain shows a very high sensing performance for Hg2+ detection in pure water reaching a detection limit of 0.2 ppb. Two additional advantages of these systems are their stability over a wide pH window and the feasibility to be recovered by a simple procedure.
Development of a pressurised liquid extraction and liquid chromatography with electrospray ionization-tandem mass spectrometry method for the determi…
2006
Amnesic shellfish poisoning (ASP) is a potentially lethal human toxic syndrome which is caused by domoic acid (DA) that originates in marine phytoplankton belonging to the Pseudonitzschia genus. A confirmatory and sensitive procedure has been developed and validated for the determination of DA in shellfish. The proposed method includes pressurised liquid extraction (PLE) with methanol/acetone (9:1), florisil ® cleanup purification inside the PLE extraction cell and detection by liquid chromatography (LC) coupled to electrospray ionization in positive mode tandem mass spectrometry (ESI-MS–MS). Comparison of ionization sources (ESI, atmospheric pressure ionization (APCI) atmospheric pressure …
Ultrasmall Rigid Particles as Multimodal Probes for Medical Applications
2011
International audience; Ultrasmall but multifunctional: Rigid imaging particles that are smaller than 5 nm in size can be obtained in a top-down process starting from a core–shell structure (core=gadolinium oxide; shell=polysiloxane). They represent the first multifunctional silica-based particles that are sufficiently small to escape hepatic clearance and enable animal imaging by four complementary techniques.
TRANSIENT AND FREE-VIBRATION ANALYSIS OF LAMINATED SHELLS THROUGH THE DISCONTINUOUS GALERKIN METHOD
2022
This paper presents a novel formulation for linear transient and free-vibration analysis of laminated shell structures based on Interior Penalty discontinuous Galerkin (DG) methods and variable-order through-the-thickness kinematics, whose combined use allows solving the shell problem with high-order accuracy throughout both the shell thickness and the shell modelling domain. The shell geometry is described via a generic system of curvilinear coordinates using either an analytical or a NURBS-based parametrization of the shell mid surface; the formulation also allows for the presence of cut-outs, which are implicitly represented by means of a level set function. After deriving the governing …
Buckling analysis of multilayered structures using high-order theories and the implicit-mesh discontinuous Galerkin method
2022
This work presents a novel formulation for the linear buckling analysis of multilayered shells. The formulation employs high-order Equivalent-Single-Layer (ESL) shell theories based on the through-the-thickness expansion of the covariant components of the displacement field, whilst the corresponding buckling problem is derived using the Euler’s method. The novelty of the formulation regards the solution of the governing equations, which is obtained via implicit-mesh discontinuous Galerkin (DG) schemes. The DG method is a high-order accurate numerical technique based on a discontinuous representation of the solution among the mesh elements and on the use of suitably defined boundary integral…
High-fidelity analysis of multilayered shells with cut-outs via the discontinuous Galerkin method
2021
Abstract A novel numerical method for the analysis of multilayered shells with cut-outs is presented. In the proposed approach, the shell geometry is represented via either analytical functions or NURBS parametrizations , while generally-shaped cut-outs are defined implicitly within the shell modelling domain via a level set function . The multilayered shell problem is addressed via the Equivalent-Single-Layer approach whereby high-order polynomial functions are employed to approximate the covariant components of the displacement field throughout the shell thickness. The shell governing equations are then derived from the Principle of Virtual Displacements of three-dimensional elasticity an…
Long-distance trade and consumption of mollusks in the Byzantine and Early Islamic periods in the Negev Desert
2021
Abstract Recent archaeological excavations in the Negev desert in the southern Levant have yielded a variety of mollusk shells originating from the Mediterranean Sea, the Nile River, and the Red Sea, uncovered in the trash mounds and settlements of Byzantine and Early Islamic sites. These remains indicate that aquatic products were among the merchandised comestibles transported across long distances. Three shellfish taxa manifest such transportation: (1) the small clam, Donax trunculus, commonly found in the exposed sandy wash zones of the Eastern Mediterranean coast; (2) the large freshwater mussel, Chambardia rubens, whose habitat stretches from the Nile River to western Africa; and (3) t…