461 research outputs found
The impact of thermal treatment on the mechanical properties of magnetic tapes : tensile test
Conference paper
Chemistry for audio heritage preservation : a review of analytical techniques for audio magnetic tapes
Vast and important cultural resources are entrusted to magnetic tape around the world, but they are susceptible to degradation, which may lead to severe replay problems. Audio magnetic tapes are complex and multicomponent devices containing organic compounds and metal systems, which can be potential catalysts for many degradative reactions in the presence of water, light, or heating. The aim of this review is to collect the literature concerning the analytical determinations and instrumental approaches that can achieve the chemical identification of the components in the tape and the degradation state. Thus, a combination of destructive (such as acetone extraction) and non-destructive techniques (such as ATR FTIR spectroscopy) have been proposed, together with SEM, ESEM, XRD and TGA analyses to assess the chemical and physical characterization of the tape with the purpose to individualize restoration treatments and optimize conditions for preservation. The impact of the studies reviewed in this paper may go beyond audio, being potentially relevant to video, data, instrumentation, and logging tapes
The safeguard of audio collections: a computer science based approach to quality control--the case of the sound archive of the arena di verona
In the field of multimedia, very little attention is given to the activities involved in the preservation of audio documents. At the same time, more and more archives storing audio and video documents face the problem of obsolescing and degrading media, which could largely benefit from the instruments and the methodologies of research in multimedia. This paper presents the methodology and the results of the Italian project REVIVAL, aimed at the development of a hardware/software platform to support the active preservation of the audio collection of the Fondazione Arena di Verona, one of the finest in Europe for the operatic genre, with a special attention on protocols and tools for quality control. On the scientific side, the most significant objectives achieved by the project are (i) the setup of a working environment inside the archive, (ii) the knowledge transfer to the archival personnel, (iii) the realization of chemical analyses on magnetic tapes in collaboration with experts in the fields of materials science and chemistry, and (iv) the development of original open-source software tools. On the cultural side, the recovery, the safeguard, and the access to unique copies of unpublished live recordings of artists the calibre of Domingo and Pavarotti are of great musicological and economical value
Surface functionalization with phosphazene substrates, Part IV: Silica and Si(100) surface functionalization using cyclophosphazenes partially substituted with trialkoxysilane derivatives and PEG-750 monomethylether, 2,2,3,3-tetrafluoropropanol and 4-hydroxyazobenzene
This paper deals with the possibility of functionalizing the surface of silicon-based materials by exploiting cyclophosphazenes containing suitable substituent groups. Thus, phosphazene trimers were prepared, containing about 50% of the reactive sites substituted by γ-aminopropyltriethoxy silane (APTES), while the residual positions in the cycle contain poly(ethylene glycol) monomethylether (MW approx. 750; PEG-750-ME), tetrafluoropropanol (TFP) and 4-hydroxyazobenzene (AzB). Using these novel materials we succeeded in surface functionalizing SiO2 beads in the coating of silicon wafers or sodalime slides and in the preparation of cyclophosphazene-based monoliths in the presence of hydrolyzed TEOS by sol–gel technique. The whole series of products has been characterized by standard spectroscopic (IR, UV-Vis, 1H-, 13C-, 29Si- and 31P-NMR, both in solution and in solid state) and thermal (DSC and DMTA) techniques. This approach to the surface functionalization of silicon-based materials containing carefully ..
Novel Multifunctional Magnetic Inorganic Composites: Synthesis and Characterization
We report the preparation of a series of new magnetic inorganic composites (MICs) with tuneable magnetic and mechanical properties. In the field of power inductive components and inductive heating, they could transfer energy with high robustness and excellent performances. Moreover, they may mitigate electromagnetic interference (EMI) in the LF and MF band. The MICs have been prepared using an alkaline or acidic activation process carried out in the presence of commercial magnetic micrometric particles made of anisotropic and isotropic Sr-ferrite. Three different matrices have been prepared, varying the type of activator, slag addition, water content, and aggregates
Novel Multifunctional Magnetic Inorganic Composites: Synthesis and Characterization
We report the preparation of a series of new magnetic inorganic composites (MICs) with tuneable magnetic and mechanical properties. In the field of power inductive components and inductive heating, they could transfer energy with high robustness and excellent performances. Moreover, they may mitigate electromagnetic interference (EMI) in the LF and MF band. The MICs have been prepared using an alkaline or acidic activation process carried out in the presence of commercial magnetic micrometric particles made of anisotropic and isotropic Sr-ferrite. Three different matrices have been prepared, varying the type of activator, slag addition, water content, and aggregates
Triptycene-Roofed Quinoxaline Cavitands for the Supramolecular Detection of BTEX in Air
Two novel triptycene quinoxaline cavitands (DiTriptyQxCav and MonoTriptyQxCav) have been designed, synthesized, and applied in the supramolecular detection of benzene, toluene, ethylbenzene, and xylenes (BTEX) in air. The complexation properties of the two cavitands towards aromatics in the solid state are strengthened by the presence of the triptycene moieties at the upper rim of the tetraquinoxaline walls, promoting the confinement of the aromatic hydrocarbons within the cavity. The two cavitands were used as fiber coatings for solid-phase microextraction (SPME) BTEX monitoring in air. The best performances in terms of enrichment factors, selectivity, and LOD (limit of detection) values were obtained by using the DiTriptyQxCav coating. The corresponding SPME fiber was successfully tested under real urban monitoring conditions, outperforming the commercial divinylbenzene\u2013Carboxen\u2013polydimethylsiloxane (DVB\u2013CAR\u2013PDMS) fiber in BTEX adsorption
ELABORAÇÃO E CARACTERIZAÇÃO DE BEBIDAS À BASE DE EXTRATO HIDROSSOLÚVEL DE SOJA COM POLPA DE PITANGA, AMORA E MIRTILO
Atualmente, observa-se uma busca do consumidor por alimentos com elevadas propriedades nutricionais e funcionais, despertando o interesse das agroindústrias por frutas com características exóticas. Este trabalho tem como objetivo o desenvolvimento de bebidas a base de soja nos sabores pitanga, amora e mirtilo. A caracterização das polpas e da bebida foi feita através de análises físico-químicas e microbiológicas, além da aplicação de análise sensorial no produto desenvolvido. Entre as análises físico-químicas de conteúdo mineral, proteínas, sólidos, lipídios e glicídios, o pH foi o descritor que melhor explicou a diferença entre as polpas e as bebidas (Análise de Componentes Principais - ACP). Na realização da análise sensorial das bebidas o índice de aceitação foi satisfatório, indicando potencial para a industrialização das mesmas e necessidade de maior intensificação do aroma e sabor no desenvolvimento do produto final
Novel Correlations between Spectroscopic and Morphological Properties of Activated Carbons from Waste Coffee Grounds
Massive quantities of spent coffee grounds (SCGs) are generated by users around the world.
Different processes have been proposed for SCG valorization, including pyrolytic processes to achieve carbonaceous materials. Here, we report the preparation of activated carbons through pyrolytic processes carried out under different experimental conditions and in the presence of various porosity activators. Textural and chemical characterization of the obtained carbons have been achieved through Brunauer–Emmett–Teller (BET), ESEM, 13C solid state NMR, XPS, XRD, thermogravimetric and spectroscopic determinations. The aim of the paper is to relate these data to the preparation method, evaluating the correlation between the spectroscopic data and the physical and textural properties, also in comparison with the corresponding data obtained for three commercial activated carbons used in industrial adsorption processes. Some correlations have been observed between the Raman and XPS data
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