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受环境和气候的影响,不同地区档案库房空气微生物的种类不同,对不同库房消毒灭菌剂的敏感性和效果会存在一定差异。为精准了解青岛地区档案库房空气微生物的物种种类,本研究通过自然沉降法采集、培养、纯化了档案库房空气微生物,并采用宏基因组测序方法对微生物物种进行了精准鉴定。为有效治理档案库房空气的微生物污染,采用甲醛高锰酸钾化学熏蒸法,对微生物污染严重的库房进行了消毒处理。结果显示,青岛地区档案库房中存在多种微生物,包括真菌、细菌和病毒,其中含量前六十的微生物物种按"属"分类的真菌有6属,细菌有51属,病毒有3属;含量前六十的微生物物种按"种"分类的真菌有5种,细菌有54种,病毒有1种。通过甲醛高锰酸钾化学熏蒸消毒15小时后,库房空气真菌消亡率为59.1%,细菌消亡率为46.6%,效果显著。本研究为精准了解档案库房空气微生物物种种类及档案库房空气消毒灭菌提供了理论依据和实践参考。 相似文献
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《文物保护研究》2013,58(2):99-110
AbstractThe deterioration of stone monuments in urban atmospheres mainly involves corrosion by acid solutions. Thus the characterization of the material is of great importance in the understanding of stone decay. In this work, samples were taken from the balcony of the Metropolitan Cathedral (Mexico City), from three different areas of the facade of the National Museum of Tepotzotlán (NW of Mexico City) and also, for comparison, new fresh stone from the quarries of Chiluca and Los Remedios. Mineralogical, petrographic, chemical and structural analyses were carried out on all the samples, and a relationship was established between the degree of decay and the stone characteristics, such as porosity, specific surface area and calcium content. The characterization of the type of stone also influences the selection of conservation treatments. 相似文献
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《文物保护研究》2013,58(2):105-112
AbstractThe degradation of coupled building stones has been simulated in a laboratory chamber using an artificial acid rain solution (‘wet’ deposition) with wet/dry cycling. The reaction of individual and coupled stones with the artificial acid rain was assessed from the pH, and confirmed by measurement of calcium ion content in the run-off. For the coupled stones, it is evident that there is a build up of damaging reaction products in the region of the lower stone closely adjacent to the upper stone. This behaviour is related to the increased time of wetness due to retained solution, containing calcium ions from runoff and anion species from the artificial acid rain solution, which allows locally enhanced reaction with the lower stone and subsequent development of salts. Where Leinster granite is the lower stone of the couple, calcium ions in the run-off from the upper stone, Portland limestone, accumulate in these regions, leading to the eventual development of gypsum in the near-surface regions of the granite, with extensive resultant degradation. The laboratory chamber allows rapid ranking of various stone combinations in the couple, and early insight into the degradation process which may ultimately assist in the development of conservation procedures. 相似文献
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《文物保护研究》2013,58(1):30-40
AbstractThe Kitora tumulus, which is thought to have been built around the late seventh to early eighth century, has beautiful mural paintings which were executed directly on a very thin layer of plaster in the stone chamber. When the paintings were found, the plaster was partly detached from the stone wall and the murals were therefore considered to be likely to fall off the wall with a casual touch or stimulation. Therefore, it was decided to detach the mural paintings and to store them flat and under controlled environmental conditions. This was initiated immediately after the excavation of the tumulus in 2004. However, fungal growth and biofilm development were observed within the stone chamber during the relocation work. In 2005, small holes containing black substances were observed on certain areas of the ceiling plaster, and following investigation an acetic acid bacterium, Gluconacetobacter sp., was isolated from the black substances. The bacterium was also isolated from the ceiling, floor, and east wall in the stone chamber in 2008 after the relocation of most of the paintings had been completed. These bacteria were shown to decompose calcium carbonate (CaCO3), one of the primary components of the plaster, and to produce organic acids such as acetic acid. Additionally, they were observed to decrease the pH of the culture media significantly in the presence of ethanol and glucose. This is the first example of the characterization of acetic acid bacteria isolated from decayed plaster paintings, and it is likely that microbes such as these bacteria have been involved in the deterioration of the plaster. Chemicals to treat microbes in the Kitora tumulus during the relocation work were selected on the basis of their antimicrobial efficacy, low potential to cause adverse effects on the paintings, and low level of toxicity to humans, depending on the condition of the plaster or stone in each area. However, some chemicals, especially ethanol, may act as a carbon source, which could encourage the growth of microbes and thereby the production of acids by the microbes when diluted to a low concentration or in a degraded state. Moreover, prior contamination by other microbial species in the form of a biofilm could also encourage the growth of the acetic acid bacteria by providing low-molecular-weight organic materials as a nutrient source. 相似文献
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《文物保护研究》2013,58(4):228-238
AbstractA procedure for collection of decay rate data from stone samples exposed in actual environmental conditions is described. This provides precise weekly decay rate data. Data were collected for 16 consecutive months for 200-year-old weathered and freshly quarried Portland stone. Problems with the use of an acrylic sheet as a control were encountered and overcome. It is suggested that glass is a better control surface. Decay rates of new and old stone differed, with new stone typically being 60–70mg/m2/day. Close agreement was found between new stone replicates. Rates for old stones were much more variable and ranged from 90–270mg/m2/day. Differences were also found in the relative contributions of solution and particulate loss to total loss between the two stones. 相似文献
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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
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《文物保护研究》2013,58(1):62-67
AbstractJuan and Jerónimo del Corral, the former an architect and the latter a sculptor, developed their artistic activities in Castile during the second third of the sixteenth century. The originality of their work lies not only in their technique but also in their iconography: they combine the Spanish tradition of plaster work with the influence of the Italian Renaissance. This paper is a documentary and stylistic study of their work and discusses the problems of technique and conservation of the cupolas and walls of polychromed and gilded plaster relief. Due to its characteristics and its sensitivity to moisture, gypsum is a material which poses specific problems of behaviour and treatment. The various deteriorations it undergoes are shown as well as their causes and possible treatment. Scientific examination has been mainly directed towards the investigation of the support by IR and EDX spectrometry, the analysis of the polychromy by microscopy and the identification of the media by gas chromatography. The results show that the Corral brothers used a homogeneous technique for the plaster support, following the Hispano-Moresque tradition, whereas the polychromy shows various influences. As regards biological deterioration, two different groups of microorganisms were surveyed: bacteria and fungi. The results obtained in areas with and without polychromy and with various levels of moisture have been compared by different sampling techniques. Nitrifying and sulphate-reducing bacteria have been identified, which are responsible for the deterioration of stone monuments. 相似文献
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Birgit Anne van Driel Sharon R. van der Meer Klaas Jan van den Berg Joris Dik 《文物保护研究》2013,58(5):261-272
ABSTRACTTwentieth century paints often contain titanium dioxide and zinc oxide based white pigments that can range from photostable to highly photocatalytic. Photocatalytic pigments can cause the degradation of paint upon UV exposure, whereas photostable pigments may be benign or can protect paintings from degradation. Hence, knowing whether or not a pigment is photocatalytic is of high importance for risk assessment and the subsequent decision making process concerning storage and exposure conditions of objects. Here we present a proof of principle, focused on titanium white paints, for an easy-to-use and low-tech application of a commercial photocatalytic activity indicator ink (PAII) on embedded paint samples or cross sections. This test determines, qualitatively, if a photocatalytic pigment is present in a white paint sample. The PAII paint sample staining application shows an obvious color change, within five minutes of UV irradiation, for paint samples containing photocatalytic pigments. A microscope with a camera and a UV source are the only necessary equipment for the application of this method. A quantitative image processing protocol is also proposed as an extension of the staining method by applying open source software analysis to measure the color change using photographs. The test was evaluated on reference paints with well-characterized pigments and applied on samples from modern paintings by Piet Mondriaan, Robert Ryman, and Lucebert, indicating the presence of harmful photocatalytic pigments in these cases. The novel application of a commercial ink on paint samples offers a simple test, not just for assessment of photocatalytic activity of titanium white pigments, but which may in future be applied for the detection of photoactive forms of zinc white and other potentially harmful semiconductor pigments in art objects. 相似文献
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《文物保护研究》2013,58(1):49-58
AbstractBlack weathering layers on stone often contain iron. This is particularly true for the Turonian sandstones which were used extensively in architecture and sculpture in Saxony. In order to obtain more knowledge about the oxidic iron phases, samples were collected in the city of Dresden. Mineralogical and analytical characterization was provided for the black layers and the supporting stone. Material originating from Cotta and Posta stone was submitted to Mössbauer spectroscopy. After ample comparisons of Mössbauer parameters and evaluation of infrared spectra it was concluded that the predominant neogenic iron phase is not iron(III) oxide hydrite (ferrihydrite) Fe2O3·1·8H2O or jarosite KFe3(SO4)2(OH)6 or goethite α-FeO(OH) but a defectively ordered precursor of this last compound, characterized by different environments of the iron(III) ions. By the reducing action of organic matter, magnetite Fe4O4 is formed and this contains up to 45% of the iron present in a black layer. 相似文献
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《文物保护研究》2013,58(3):171-176
AbstractThe weathering of stone monuments results in the leaching of calcite, with a consequent increase in porosity and decrease in integrity. A new method of consolidation uses organic matrix macromolecules extracted from Mytilus californianus shells to induce the precipitation of calcium carbonate within the pores of the stone. The procedure has been tested in the laboratory on samples of bioclastic limestone and dolostone, by measuring changes in total porosity, amount of water absorbed and superficial cohesion. The results appear to confirm the success of the treatment. 相似文献
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ABSTRACTThe pyroclastic rocks belonging to the Late Eocene-Miocene volcanic activity that occurred in Sardinia between 38 and 15 Ma ago were widely used as construction materials in several Romanesque churches of the easternmost Logudoro area, as well as in large parts of the Sardinia territory. In this work, the ancient Cathedral of Nostra Signora di Castro (twelfth century) was taken as a representative case study. There is no historical or archaeological evidence of ancient quarries. Based on the geochemical, petrographic, and volcanological data on several samples from an extensive field area (approximately 150?km2), a geographical zoning of the volcanics has been recognised. In the Oschiri sector, there are three different sub-zones, which can be identified with different volcanic rocks: less fractionated rocks (Differentation Index ～70–78); intermediately fractionated rocks (D.I. ～76–79); and more fractionated rocks (D.I. ～77–82). To identify the origin of the ignimbrite rocks of the Church of Nostra Signora di Castro, two statistical methods were used: stepwise linear discriminant and canonical analysis. Moreover, to define the geochemical transformation processes induced by the alteration, a comparative study of concentrations of major and trace elements measured by XRF and SEM-EDX analyses on the surface portion and the innermost areas of the stone was made. 相似文献
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Ainara Zornoza-Indart Paula Lopez-Arce Karima Zoghlami Nuno Leal Joaquim Simão 《文物保护研究》2013,58(2):73-89
ABSTRACTCalcarenite stone samples from a historic building (Bizerte, Tunisia) were collected and treated under different environmental conditions with several consolidating products: alkoxysilane (ethyl silicate), a surfactant-templated novel sol–gel, Ca(OH)2, and SiO2 nanoparticles. These were subjected to marine aerosol accelerated aging cycles and studied by several non-destructive tests and techniques to assess the stability of the products. Results show that weathering caused by salt crystallization is not inhibited but it is slowed down due to the enhancement of superficial mechanical properties (surface cohesion and micro-hardness) achieved after one month of treatments application. A high or low relative humidity of the consolidation environment significantly affects the final mechanical and aesthetical physical properties and therefore conditions the durability of the treated substrates, even producing higher damage than observed in the blank specimens, depending on the product. 相似文献
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《文物保护研究》2013,58(4):242-248
AbstractDilute solutions of epoxy resins have been used successfully in the past to consolidate deteriorated, porous stone. However, the appearance change (darkening, yellowing) on curing has proved to be a deterrent to the wider use of these materials by conservators. In the study reported here, it is shown that solvent washing to remove surface-deposited resin and exposure to sunlight are effective methods for restoring the original visual appearance of consolidated outdoor stone. 相似文献
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《文物保护研究》2013,58(4):298-313
AbstractFive different methods for cleaning the limestone façades on what was originally the Workers Hospital in Madrid are analyzed in this paper. Due to the pollution in the surrounding air, just 20 years after a prior cleaning operation, sulfate crusts had developed on the entire stone surface of the building. The gypsum mortar used in the original masonry constituted an additional source of sulfur. Limestone is a traditional building material in Madrid and its surroundings. The petrography, mineralogy and petrophysical properties of the biomicrite, pelmicrite and biopelmicrite varieties of limestone identified in the hospital walls were determined. Analysis of a black layer on the stone surface showed that it consisted primarily of sulfate crusts. The cleaning methods tested were alkaline gels (sodium hydroxide and potassium hydroxide), pressurized hot water, glass bead blasting and latex peeling. The criteria for assessing the effectiveness and potential risks of the various cleaning systems included changes in the chromatic parameters of the stone, the formation of alteration products (i.e. salts) and modification of the stone surface. The stones cleaned with the three most effective methods, together with a rain-washed stone as a reference, were washed with water to generate an artificial runoff. The collected drain water was analyzed to determine the presence of any by-products from the cleaning process. The method found to be most effective and which caused the least alteration to the stone surface was glass bead blasting, particularly after adjustment of the bead size and pressure conditions used for the test. 相似文献
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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
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《The Reference Librarian》2013,54(67-68):273-287
Summary The Colorado State University Libraries' instructional outreach services have undergone significant changes since the reorganization of Reference Services in January of 1998. The new organizational structure created a separate group for instruction, outreach and staff training, which includes the extended university programs position (distance learning), and a new position, the undergraduate instruction librarian. This new group gives the Libraries an avenue in which to provide focused instruction to the Colorado State University community and limited outreach to campus affiliates and the Fort Collins community. This article discusses outreach activities before and after the reorganization including services to specific populations such as African Americans, Hispanics, distance learning populations and extension services, undergraduates, and disabled students. 相似文献
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《Communication Teacher》2013,27(4):142-147
Objective: This activity is designed to improve team performance by giving students a better understanding of their own and their peers’ personality traits. Consequently, the exercise is intended to: (1) improve communication between team members; (2) increase understanding of and appreciation for the diversity of personality traits; and (3) reduce the misunderstandings and frustrations that often impede successful teamwork. Courses: This exercise can be used for any high school, undergraduate, or graduate course that requires students to work in a team setting for an extended period of time. 相似文献
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Yadong Ji 《Communication Research Reports》2020,37(3):65-73
ABSTRACT Preexposure prophylaxis (PrEP) is an effective medicine against HIV transmission. PrEP can be especially beneficial in the men who have sex with men (MSM) communities. However, medical studies have associated MSM’s PrEP use with undesired riskier behaviors (risk compensation), such as reducing condom use and acquiring more sexual partners. Fact sheets are important information sources for MSM to learn about PrEP and can potentially prevent risk compensation. This study compared three accessible fact sheets (the Truvada fact sheet, the CDC fact sheet, the FDA fact sheet) in terms of their effects on MSM’s PrEP use intention and risk compensation intention (n = 600). The results showed that the CDC and the FDA fact sheets significantly encouraged higher PrEP use intention without provoking higher risk compensation intention. To promote PrEP use without raising risk compensation intention, fact sheets might be good information sources for the MSM population. 相似文献