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91.
Cecilia Sanna Armida Sodo Giuseppe Laguzzi Giovanna Mancini Marina Bicchieri 《Journal of Cultural Heritage》2009,10(3):356-361
The need to preserve cultural heritage on paper requires the setting up of methods and treatments that can be applied to original documents. The cellulose main degradation processes are hydrolysis and oxidation. Only the first one has been widely investigated. The Istituto Centrale per la Patologia del Libro (ICPL) focused its attention on oxidation phenomena and studied a particular class of reducing agents, namely the borane-amine complexes. During the investigation it was found that the borane tert-butylamine complex, besides being the most promising reducing agent, was also able to react with carboxylic functions. In the present study 1H and 13C NMR, Pulsed field gradient NMR spectroscopy as well as Raman spectroscopy were used as analytical tools to disclose the mechanism of the interaction between the borane tert-butylamine complex and the carboxylic functions. Given the complexity of the paper/environment interactions and the subsequent degradation phenomena, we worked on simplified models based on small carbohydrate molecules in order to reproduce the behavior of degraded paper after reductive restoration. Modified D-glucose and D-cellobiose were used in this first step in order to set up the analytical methods before approaching more complex systems such as microcrystalline cellulose and paper. Our results give the experimental evidence that borane tert-butylamine complex is also able to neutralize acidic functions. This finding has important perspectives in paper restoration. 相似文献
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93.
Nicoletta Marinoni Alessandro Pavese Roberto Bugini Giuseppe Di Silvestro 《Journal of Cultural Heritage》2002,3(4):915
Black limestone samples from the quarries of Varenna (Lecco, I), Cene (Bergamo, I) and Riva di Solto (Bergamo, I) and widely used in Lombard architecture have been studied in terms of mineralogical, petrographic and chemical properties in order to provide a detailed characterisation and allow an unambiguous determination of their provenance. The inorganic and organic fractions have been separated from each other, and investigated using X-ray powder diffraction, atomic absorption, Hg-porosimetry, high performance liquid chromatography, gas chromatography, nuclear magnetic resonance and Fourier transform infrared spectroscopy. The occurrence of specific mineral phases, some binary chemical patterns (Fe/Mn, Zn/Sr, Zn/Co and Na/Cd) and the carbon chain relative molecular masses has proven to be useful markers to characterise unequivocally the materials studied. 相似文献
94.
Teresa Cerchiara Giuseppe Chidichimo Maria Caterina Gallucci Rita Ferraro Danilo Vuono Alfonso Nastro 《Journal of Cultural Heritage》2009,10(3):396-402
One of the problems in the field of cultural heritage is the degradation of artworks and especially paintings. They appear very sensitive to environmental conditions. In this work, Spanish broom canvas is proposed as a novel painting support. In order to assess the deterioration properties of this new type of canvas, three degradation processes (exposure to wet atmosphere, to acidic attack and to UV light) were simulated and investigated. The deterioration state of the samples was monitored with Infrared Spectroscopy (FT-IR) and Thermogravimetric Analysis (TGA). The structure of the canvas was also analyzed by Scanning Electron Microscopy (SEM). These techniques were successfully applied to study the occurrence significant changes of samples. The exposure to acidic and UV attack produced deep changes on the samples (only on the canvas surface in the case of UV light), while no significant effect was identified on the sample after the exposure to wet atmosphere. The results obtained from Spanish broom canvas are reported in comparison to flax canvas. 相似文献
95.
Prompted by the need to move an aged and sorely neglected print reference collection into a new smaller academic medical library, the Reference Team of the Dana Medical Library at the University of Vermont embarked on a massive project to shrink and revitalize its paper reference collection. Employing a comprehensive and contemporary approach, the project ultimately resulted in a refurbished collection that would more effectively meet the information needs of the 21st century library user. This paper describes the process employed, and the numerous quality improvements to the physical collection, supporting infrastructure, and collection management practices that resulted. 相似文献
96.
Sacchetti R Ceciliani A Garulli A Masotti A Poletti G Beltrami P Leoni E 《Journal of sports sciences》2012,30(7):633-640
A cross-sectional study was carried out to analyse, through a limited number of fitness tests, the main conditioning and coordinative abilities in children aged 8-9 years, and their relationship with gender, anthropometric variables and physical activity habits. The height and weight of 256 boys and 241 girls were measured and information about physical activity habits was collected using a self-administered questionnaire. Physical performance was assessed by means of a few standardised tests: 'sit & reach', medicine-ball forward throw, standing long jump, 20 m running speed, and forward roll test. In both boys and girls, body weight and body mass index (BMI) were positively correlated with the medicine-ball throw performances and negatively correlated for the standing long jump and speed tests, while no association was found with tests measuring back flexibility and total body coordination. Daily physical activity and participation in sport were not significantly correlated with body weight and BMI, but were positively associated with children's motor performance. The standardised fitness tests selected in the current study have been found to be suitable to identify fitness levels of primary school children. Thanks to their limited number and ease of measurement, they can be used in any school context to classify children and for monitoring the effects of targeted interventions promoting physical activity. 相似文献
97.
Lima-Oliveira G Lippi G Salvagno GL Montagnana M Picheth G Guidi GC 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2012,22(2):180-186
Introduction
The validation process is essential in accredited clinical laboratories. Aim of this study was to validate five kinds of serum vacuum tubes for routine clinical chemistry laboratory testing.Materials and methods:
Blood specimens from 100 volunteers in five diff erent serum vacuum tubes (Tube I: VACUETTE®, Tube II: LABOR IMPORT®, Tube III: S-Monovette®, Tube IV: SST® and Tube V: SST II®) were collected by a single, expert phlebotomist. The routine clinical chemistry tests were analyzed on cobas® 6000Results and conclusions:
Basically, our validation will permit the laboratory or hospital managers to select the brand’s vacuum tubes validated according him/her technical or economical reasons, in order to perform the following laboratory tests: glucose, total cholesterol, high density lipoprotein-cholesterol, triglycerides, total protein, albumin, blood urea nitrogen, uric acid, alkaline phosphatise, aspartate aminotransferase, gamma-glutamyltransferase, lactate dehydrogenase, creatine kinase, total bilirubin, direct bilirubin, calcium, iron, sodium and potassium. On the contrary special attention will be required if the laboratory already performs creatinine, amylase, phosphate and magnesium determinations and the quality laboratory manager intend to change the serum tubes. We suggest that laboratory management should both standardize the procedures and frequently evaluate the quality of in vitro diagnostic devices. 相似文献98.
Wood artefacts are subject to damage by biologic infestations due to bacteria, insects, and fungal species. One of the worst feared attacks is due to the xylophagous insects whose larvae feed on wood by boring galleries, at the expense of building timbers and worked woods. These beetles are responsible for daily destruction of the world’s wooden cultural heritage, and their elimination has been always a big problem for conservation of wood. The need to avoid the use of chemical methods in conservation for pest control has led to the development of various non-chemical, non-toxic treatments. Among these, heating with microwaves (MW) seems to be one of the most promising, since it has already shown its high efficacy in destroying pests. Insect-infested wood remediation by MW heating in conservation is based on the larger thermal increment induced in larvae than in wood, due to their different dielectric permittivity in the GHz frequency range. However, the side effects that may occur due to MW heating of wood, such as dehydration, have never been discussed so far. Here we study the possible application of microwave heating as a remediation method for wood samples infested by the larvae of the insect Hylotrupes bajulus. We show that it is possible to set up exposure conditions able to achieve 100% of larvae death and that are sufficiently mild not to induce significant dehydration of the exposed wood from which shrinkage effects may derive. Indeed, under these conditions, MW-induced wood dehydration on cubic and parallelepiped sweetgum samples can be kept under control and to percentages as low as 0.4% (w/w). 相似文献
99.
Benedetto Bozzini Belén Alemán Matteo Amati Marco Boniardi Vincenzo Caramia Giuseppe Giovannelli 《文物保护研究》2017,62(8):465-473
A recent assessment (Giovannelli, G., D'Urzo, L., Maggiulli, G., Natali, S., Pagliara, C., Sgura, I. & Bozzini, B. 2010. Journal of Solid State Electrochemistry, 14: 479–94.) of the corrosion state of a late Bronze Age artefact (ca. 1100 BCE) exposed to a coastal environment, based on optical and scanning electron microscopies, X-ray fluorescence mapping, and X-ray diffractometry, led to recognition of bronze disease conditions essentially related to the presence of nantokite locked inside mesoscopic subsurface pits. The object was then treated successfully with a novel electrochemical approach specifically designed to allow penetration of the electric field into deep, screened pits. In order to further develop and optimize this promising approach by fine-tuning the capabilities of electrochemical control, more insight is required on the specific morphochemistry of the corrosion product scenario. To this end, here we report a space-dependent compositional and chemical-state analysis, performed with synchrotron-based scanning photoelectron microspectroscopy. The investigated object consists of a segregated cast bronze. The prevailing corrosion form is preferential attack of Sn-rich phases, accompanied by a synergistic type of Sn and Cu attack triggered by the peculiar type of decuprification taking place in a bronze disease framework and characterized by the formation of Sn(OH)Cl as a result of local HCl generation in the Cu corrosion process. 相似文献
100.
Margaret Kirkwood Bob Sharp Giuseppe de Vito & Myra A Nimmo 《British journal of educational technology : journal of the Council for Educational Technology》2002,33(2):159-172
Traditional approaches to teaching exercise physiology are costly in terms of staff time and consumable expenses. Ethical considerations, large student numbers and availability of technical expertise magnify the delivery problems. In an attempt to overcome these problems, a CD-ROM version of a basic course in exercise physiology was designed and delivered to a group of undergraduate sport and exercise science students. It simulated five tests of aerobic endurance which are traditionally taught using laboratory methods. A controlled experiment was conducted to compare the two delivery methods, as part of an independent, formative evaluation. Although there were equal knowledge gains and the CD-ROM design and content were well rated by students who used it, this approach has engendered less student interaction, commitment to wider reading and in-depth understanding. Tutorials and other approaches designed to promote more active learning are now being introduced to accompany the use of the CD-ROM. 相似文献