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1.
《文物保护研究》2013,58(3):149-153
AbstractA broth containing the sulfate reducing bacterium Desulfovibrio desulfuricans was used to treat samples of reagent calcium sulfate, gypsum-rock specimens, fragments from a marble monument with a black weathering crust rich in gypsum, and a marble monument with similar crust. Calcite was found to have formed on all treated surfaces suggesting that this microbe has the potential to clean crusted marble monuments whilst also regenerating calcite, the parent mineral of the marble. 相似文献
2.
《文物保护研究》2013,58(4):201-205
AbstractWe have reacted Georgia marble in sulfur dioxide (SO2) enriched atmospheres and calculated the reaction rate constant. This constant was derived from surface reduction data, obtained by leaching thereaction product from samples exposed for different periods of time. Application of this constant to marble weathered in known ambient levels of sulfur dioxide (SO2) and relative humidity, allows the prediction of the thickness of the resulting gypsum crust formed over a given period of time. We have found that the crust grows outwards due to calciumions which migrate from the interior and then react with sulfur dioxide at the sample surface. Thus, anytreatment of the sulfated marble should include the considerations that the crust only masks the marble surface and is not an integral part of the original sculpture, and that cavities exist in the underlying layer of marble from which the calcium ions were selectively depleted. 相似文献
3.
《文物保护研究》2013,58(3):193-200
AbstractThis paper reports the process of deterioration of the white marble used in the Alhambra of Granada, and its consequences. Variations in mineralogical composition, microscopic topology, hardness, compressive strength, propagation of ultrasonic waves, absorptIon and diffusion of water and properties related to the pore structure were studied. The relationships between these factors, the visible deterioration and possible mechanisms are discussed. A preliminary evaluation of some protective treatments was carried out. The results can also be applied to white Macael marble used in other monuments in an environment with wide fluctuations in temperature and relative humidity. 相似文献
4.
《文物保护研究》2013,58(4):197-204
AbstractThis work combines our observation that the details of marble statues that have already been lost from the calcite surface are preserved in the gypsum layer, with our research on the mechanism of marble sulfation, to lead to a consolidation of the gypsum, transforming it back to calcium carbonate (calcite) using carbonate ions in solution. Our research shows the mechanism of the conversion of gypsum to calcite, the rate determining steps being the desorption and diffusion of CO2?3 We found that the reproduction of the surface detail and the improvement of the mechanical properties was very satisfactory. 相似文献
5.
《文物保护研究》2013,58(1):34-44
AbstractSulphuration is the main destroyer of marble, producing imaginary (not true) patina. Other reasons for the discoloration of marbles are discussed. Magnesium silicate saturated with de-ionized water is a safe and simple cleaner. Sintolite is advocated as an adhesive for marble rather than the general more fluid epoxy resins. Solid polyvinyl acetate is strongly advocated as the basis for sma1l repairs to internaIly housed marble. The consolidation of marble is discussed and a method for internal exhibits recommended. Conservation of unbaked clay is touched upon, and a method for the repair of terracotta suggested together with a process for the reproduction of a glazed frieze using a latex mould and epoxy-reinforced plaster casts. A few remarks are made concerning the dangers of cleaning alabaster with water. The commentary is of a general nature and is not intended as a strict blueprint for any particular object. 相似文献
6.
《文物保护研究》2013,58(1):25-37
AbstractMarble specimens were impregnated with epoxy resins by first soaking the specimens in a solvent and then treating them, in steps, with increasing concentrations of the resin in the resin-solvent mixture. This resulted in impregnation to several centimeters’ depth into the specimen. Both impregnated and non-impregnated specimens were subjected to 3000 ppm SO2 atmospheres in a dynamic system. X-ray diffraction and fluorescence studies to determine the deterioration quantitatively, revealed that transformation of the outer layer of non-impregnated marble into primarily calcium sulfite stopped after a maximum of 15 mole percent conversion under normal conditions of humidity. While certain impregnated marble specimens showed significant protection from SO2 attack, other impregnated specimens revealed more reactivity than the controls. A partial explanation of this has been obtained by scanning electron microscopy which showed that the resin films on the surface were perforated. Coatings of certain acrylics provided some additional protection to impregnated specimens. 相似文献
7.
《文物保护研究》2013,58(3):118-126
AbstractA series of corroded stone specimens from Salzburg monuments was examined by electron-probe microanalysis. The crusts arose from environmental effects, in the case of marble primarily from SO2. Deterioration phenomena can be correlated with stone surface features. 相似文献
8.
9.
《文物保护研究》2013,58(3):177-188
AbstractThe examination of the original polychromy of a fourth century B.C. classical Greek marble basin revealed a number of unusual pigments. In addition to natural cinnabar, and Egyptian blue, analysis has shown the presence of wild madder (Rubia peregrina) as the colorant in a purple pigment. This is one of the very few instances in which the use of madder as a colorant in classical painting has been established analytically. The white pigment was found to be neutral lead carbonate (cerussite). The use of this carbonate in painting is extremely rare. The yellow pigment was identified as misy (jarosite). The use of jarosites, iron sulphates, as pigments in painting has not been reported previously. 相似文献
10.
AbstractThe recent development of a phosphate hardening paste without oxalates, as well as consideration of the mixed calcium oxalate-phosphate composition of the hardest urinary stones, provide evidence to suggest that the formation of some patinas is the result of old protective treatments on stone surfaces. The formation of patinas with phosphates and oxalate scialbatura on marble and limestone is discussed as a contribution to the debate amongst conservators and scientists about the nature, composition and origin of these patinas. It is concluded that for the formation of both the inner part and the outer part of the patinas, the concurrent action of microorganisms and man is necessary. In both cases, man provides the foods and the microorganisms effect the transformation. 相似文献
11.
《文物保护研究》2013,58(5):291-305
AbstractThe possible meanings in conservation of the word authenticity are discussed and some different definitions are briefly evaluated. Recent research showing the brain reacts differently to the concepts of copy and authentic is reviewed. The relationship between cultural heritage charters and how authenticity has been employed in them is explored with examples from the Athen's Charter, The Venice Charter, The Nara Document, The San Antonio Declaration, and the UNESCO World Heritage Documents. Several examples are discussed in the text concerning the interactions between authenticity and restoration, employing the examples of ancient buildings and old master paintings. Some of the important writings on the subject of authenticity by scholars and art historians are reviewed. Criteria which could be used to evaluate the concept of authenticity in different cultural settings are discussed and these are illustrated with case studies taken from restoration carried out on ancient marble sculptures, the Sistine Chapel frescoes by Michelangelo, and the artwork of several prominent forgers. Given that concerns about the authenticity of art are multi-dimensional, it is important that the present fragmentation of the arguments concerning authenticity across the disciplines properly take into account the conservation field and are aware of the debates within conservation concerning this topic. The questioning of the relevance of authenticity is a healthy process, and may now be framed quite differently from the way in which it was discussed even 20 years ago. 相似文献
12.
Objective: This study was undertaken in order to determine how health sciences libraries in a ten-state region are using Loansome Doc, with an emphasis on whether this tool continues to be used to serve unaffiliated health professionals. Methods: Usage data were examined and health sciences libraries were administered a survey to determine how they are using this tool. Results: Loansome Doc usage across libraries is low and declining, and a number of libraries do not serve unaffiliated health professionals with this tool. Conclusions: Use of Loansome Doc is low and declining, in part, due to license restrictions, declining interlibrary loan, and the prevalence of alternatives, such as OCLC's ILLiad, for document delivery to affiliated users. 相似文献
13.
The medical ultrasonic phased array technology was modified for the non-destructive testing of marble sculptures and the feasibility of the approach was evaluated. For this purpose, 1?MHz, 64-channel phased array electronic and phased array transducers were developed. The specifications of the electronics and the transducers are presented and discussed. Ultrasound images of inner structures of a marble sculpture are presented. The problem of the acoustic matching layers for different states of deterioration is discussed and the developments in view of a suitable matching layer solution are presented. This matching layer is combined with a new coupling technique that protects the marble surface. The results of experiments on ultrasound phantoms and on a marble sculpture are presented. 相似文献
14.
John Dunn's The Studio (Bantam, 95¢) Bob Thomas' Thalberg: Life and Legend (Bantam, $1.25) Mrs. D.W. Griffith's When the Movies were Young (Dover, $2.50) 相似文献
15.
Craig Locatis Cynthia Gaines Wei-Li Liu Michael Gill Michael Ackerman 《Journal of the Medical Library Association》2015,103(2):78-82
Objective:The study tested the efficacy of providing distance learning with real-time videoconferencing to broaden high school student knowledge of health careers.Methods:A pilot program was tried out and extended over ten years to include other schools in four different time zones and the National Library of Medicine. Survey results, site visits, and continued school participation were used as effectiveness indicators. Student ratings, site visits, and ongoing discussions were used to evaluate critical factors in the program.Results:Nine program factors contributed to success.Conclusions:Synchronous communication can be effective for outreach to special populations given appropriate infrastructure, technology, program design, and implementation. 相似文献
16.
《The Journal of Academic Librarianship》2022,48(6):102603
BackgroundDuring the COVID-19 pandemic, students have trouble coping with the available health information regarding the coronavirus in their daily lives because of misinformation.ObjectivesThe aim of this study was to evaluate online health information seeking and digital health literacy among information and learning resources undergraduate students at Taibah University during the COVID-19 pandemic.MethodsTo investigate the primary goal, this study used a simultaneous exploratory mixed methods design. Seventeen students participated in phone interviews, and 306 were invited to complete an online survey.AnalysisThe collected data was analyzed using both quantitative (SPSS) and qualitative (NVivo 10) methods.ResultsSearch engines, social media, and YouTube were most often used by the respondents as sources to search for COVID-19-related information. COVID-19 symptoms, restrictions, and the current spread of COVID-19 were the most searched topics by the respondents. Significant and relevant differences emerged for the digital health literacy subscales “information search” and “adding self-generated content”. However, there were no significant differences in the digital health literacy subscale “determining relevance”.ConclusionUsing the internet to provide health information tailored to the needs and interests of students to seek health information online and thereby improve their health literacy. 相似文献
17.
Mohammadreza Hashemian Firoozeh Zare-Farashbandi Nikoo Yamani Alireza Rahimi Peyman Adibi 《Journal of the Medical Library Association》2021,109(1):33
Objectives:Access to high-quality information improves the quality of patient care, but lack of time and sufficient skills in information seeking can prevent access to information by clinicians. To solve this problem, clinical informationists can provide high-quality, filtered information for clinical team members. This study identified the core competencies that clinical informationists need to effectively fulfill their roles on clinical teams.Methods:Participants were selected purposefully from clinicians and medical librarians. Data were collected through semi-structured interviews and analyzed using qualitative content analysis.Results:The authors identified six competencies—communication, research, education and training, domain knowledge, information services, and technology—which together were used to develop a “CREDIT” model of core competencies for clinical informationists.Conclusions:The CREDIT model can be used as criteria for evaluating the performance of clinical informationists as well as for developing and assessing clinical informationist educational programs and curriculums. 相似文献
18.
Jonathan Eldredge Melissa A. Schiff Jens O. Langsjoen Roger N. Jerabek 《Journal of the Medical Library Association》2021,109(1):68
Objective:The authors used an assessment rubric to measure medical students'' improvement in question formulation skills following a brief evidence-based practice (EBP) training session conducted by a health sciences librarian.Method:In a quasi-experimental designed study, students were assessed using a rubric on their pre-instructional skills in formulating answerable EBP questions, based on a clinical scenario. Following their training, they were assessed using the same scenario and rubric. Student pre- and post-test scores were compared using a paired t-test.Results:Students demonstrated statistically significant improvement in their question formulation skills on their post-instructional assessments. The average score for students on the pre-test was 45.5 (SD 11.1) and the average score on the post-test was 65.6 (SD 5.4) with an average increase of 20.1 points on the 70-point scale, p<0.001.Conclusion:The brief instructional session aided by the rubric improved students'' performance in question formulation skills. 相似文献
19.
Richard G. Lawson Delbert D. Smith Katherine Shervis 《Communication Booknotes Quarterly》2013,44(10):9-11
Richard G. Lawson, Teleconferencing in Wisconsin (October 1971) Delbert D. Smith, Legal Aspects of Teleconferencing (October 1971) Katherine Shervis, Legal and Political Aspects of Satellite Telecommunication: An Annotated Bibliography (June 1971) Multidisciplinary Studies of the Social, Economic and Political Impact Resulting From Recent Advances in Satellite Meteorology: Interim Report (two volumes, June 1971) COMSAT Technical Review is a new journal to be published twice a year (the first issue was dated Fall 1971) Report to the President and Congress is issued annually in the late Spring or early Summer. The past six reports (1965-70) Annual Report is the financial report to Comsat stockholders, and copies for 1967-71 are now available Pocket Guide to the Global Satellite System (January 1972) Glossary of Terms and Definitions for International Satellite Television Services (September 1971) U.S. Domestic Satellite Communications: A Summary of Comsat's Proposals (March 1971) Intelsat Research and Development Program (March 1972) 相似文献