共查询到20条相似文献，搜索用时 93 毫秒
1.
Jens Stenger Narayan Khandekar Ramesh Raskar Santiago Cuellar Ankit Mohan Rudolf Gschwind 《文物保护研究》2016,61(6):348-361
A treatment with projected light for Mark Rothko's Harvard Murals (1962) is proposed. The group of five paintings on canvas has changed color due to the presence of a fugitive red pigment and excessive exposure to natural light in a room with large windows. For the conservation of Rothko's Harvard room, it is brought into context within his other commissions and environments. The original color of the works is determined by the digital restoration of contemporary photographs. With a camera projector system a compensation image is calculated that is projected onto the original canvas resulting in a restored color appearance. This approach of inpainting with light is compared with considerations of cleaning and inpainting in conventional conservation treatments. Overall lighting and architecture including the unusual wall color carefully chosen by Rothko play a key role in the treatment of the Mural cycle as an environment. 相似文献
2.
The protection of works of art and cultural assets against light-induced aging is vital when planning exhibitions. Newly developed lighting systems render the selection of suitable light sources more difficult, not least in the context of energy–economical systems. This study accordingly examines different lighting systems (fluorescent tubes, halogen lamps, low-voltage metal halide lamps, and LED lamps) in terms of the damage potential they hold for the materials concerned. The changes in color were evaluated using the CIEDE2000 color-difference formula. This study focuses on selected organic materials and shows that changes in color already occur after only a brief exposure time. The color changes induced by the fluorescent tubes were consistently more intense than those induced by the other light sources. The results obtained with the remaining lamps show that the color changes depend more on the material under investigation than on the source used. The changes determined after a relatively short exposure period (five months) vividly demonstrate that exposing sensitive materials to light for longer terms (as is the case during a permanent exhibition) is most definitely a non-viable option. 相似文献
3.
The impact of the spectral composition of light on the discoloration of paint pigments has been investigated for the case of lead chromate sulfate, an unstable yellow pigment used by Vincent van Gogh and other painters. With LEDification, museum lighting is moving from using halogen to LED lamps. LED light sources have a significantly different spectral composition than halogen lamps. To understand the impact of these differences on pigment stability, the wavelength dependence of pigment discoloration was determined. Contrary to the expectation that lower wavelength photons induce more damage than higher wavelength ones, UV (394?nm), blue, and cyan light all lead to similar levels of discoloration of a pigment for the same level of radiant power. By understanding this wavelength dependence, it becomes possible to create white light LED lamps with a spectral composition tuned to minimize the degradation effect. An existing LED solution with a modified emission indeed resulted in 30% less color change in the experiment than halogen. Furthermore, a method is proposed to optimize the LED spectra by tuning to the properties of each specific artifact. Simulations show that this can reduce the damage of the light source by 45% in specific cases. 相似文献
4.
《The Reference Librarian》2013,54(86):43-56
SUMMARY This article introduces the subject of animals as viewed by the world's religions. It disputes the common perception that Eastern religions are entirely “animal friendly” while Western religions are wholly uncaring toward animals. The author reviews print-resources on the status of animals in world religions to assist librarians in collection development. The reviews are categorized to suggest which resources would be most appropriate for: all libraries; public libraries; and academic libraries. 相似文献
5.
ABSTRACTHistorical pedal harps from the early nineteenth century are highly adorned objects, decorated with various techniques such as polychromy, gilding, decoupage, and gilt composition ornaments. Even though a large number of such instruments are kept in private and public collections, until now their decorative features have not been examined systematically. Moreover, little has been written about the motives behind the choice of various decorative techniques by harp makers. This article presents results from the investigation of a double-action harp made in 1818 by Erard, the leading manufacturer of harps in Regency London, focusing on the technological aspects of its decorative features. Various analytical methods, such as visual examination, microscopy, SEM-EDX, FTIR, and Py-GC-MS, were used to identify the inorganic and organic components in the coating of the harp and to analyse its stratigraphy. Inspection with ultraviolet light revealed details of the original layers and of later additions, while radiography made the internal structure as well as damaged areas and repairs visible. The outcome of this object-based examination was complemented by archival research on the Erard firm, providing new insight into Erard’s production and marketing strategies. 相似文献
6.
《文物保护研究》2013,58(4):257-266
AbstractA study of the accelerated light fading behavior of face-mounted color photographic materials has shown that alterations on the surface of the materials influence their fading characteristics. With the help of spectral density measurements it became apparent that the application of materials such as silicone rubber, adhesive film and acrylic sheeting, but also laminating films, onto the surface of the prints accelerated the degradation of the colorants, especially the yellow dye, in chromogenic materials. In the case of silver dye bleach materials, however, the opposite effect was observed. The influence of the material combination on the stability of face mounted color photographic prints was demonstrated to vary considerably. In order to better assess the inherent damage potential of the materials themselves, these were examined by means of instrumental analysis and measurements of pollutant gasses. Besides off-gassing compounds such as acetic acid and changes in pH caused by aging of the adhesive, face-mounting with a rigid plastic sheet (acrylic glazing) also affected the respective fading behavior of the various materials that were tested. 相似文献
7.
ABSTRACT The automated library system (ALS) has undergone significant changes since its inception in the 1970s. It is no longer simply a database to house and retrieve a library's holdings. It has become an integrated library system (ILS) comprised of robust clusters of systems involving every process and module related to libraries. The Internet, open source, the increase in electronic resources, and the rising expectations of library users are changing the nature of the ILS. Library vendors are at times struggling to keep up with the demand for new services while providing support for existing services. This article details the evolving role of the ILS and discusses where it could and should be headed. 相似文献
8.
ABSTRACTFrom trial to implementation, technical services staff play an important role in shaping awareness and expectations of new or updated electronic resources. With appropriate message control during the rollout process, technical services staff can positively influence understanding and awareness of resources while keeping co-workers’ and patrons’ expectations in check. At the same time, by embracing this public service role, technical services acts as a full partner with public services in mediating resources to patrons. This article explores technical services’ public-facing role by describing a protocol for managing rollouts that emphasizes timing internal and external communications, providing training and support materials, and maintaining accuracy and objectivity in all rollout communications. 相似文献
9.
《The Reference Librarian》2013,54(69-70):119-126
Summary “Communication” is the key to providing appropriate library hours and services for adult learners, students twenty-four years of age and older. This report of a survey at Western Oregon University shows that while there are some differences, the needs of both adult learners and traditional students may be similar. Both groups have a need for a variety of library hours, especially evening and weekend hours, and for remote access to both library collections and services. 相似文献
10.
ABSTRACT The restoration of the Roman building of the third-fourth century CE called Minerva Medica, in Rome, highlighted a problem concerning the choice of the color of the bricks for integration. Current conservation practice in Italy favours a restoration that as much as possible is consistent with the original but leaves some visible differences to a careful observer. Color measurement is usually performed using portable spectrocolorimeters that provide the reflectance spectrum and also colorimetric parameters such as L* a* b*, h* L* C*, RGB, etc. In other sectors, such as for olive oils, for wines, and also for the colors of commercial products, sensory panels are used to provide results of difference/similarity and are known to be similar to observations made by consumers. In this study, data from a top quality spectrocolorimeter and from a sensory panel are compared. Twenty non-professional people were involved in the comparison between seven restoration bricks and three ancient Roman bricks from the studied site. Observations took place in a room with controlled lighting, and each observer filled out a sensory card using about 2000 known comparison colors. Comparison of the results was carried out with graphic methods and by means of cluster analysis. The results show that the sensory panel could be a useful alternative to colorimetry, while cluster analysis allowed a significant response to questions posed by conservation professionals, and was confirmed by other graphic-statistical methods. 相似文献
11.
《文物保护研究》2013,58(4):161-169
AbstractA very moderate, non-destructive radioactivation of oil paintings, induced by thermal neutron bombardment, such that approximately only one in 1012 of the atoms comprising any painting is transformed into a radioactive species, has been found to produce temporary radioactivity sufficient to expose photographic film placed in direct contact with the paintings.The resulting autoradiographs resemble conventional X-radiographs in that they reveal structural details in depth of both the painting and its support. Since the radioactivities arising from the different elements within a painting decay in different manners and at different rates, a series of significantly distinct auto radiographs can be obtained of any painting by making exposures through appropriate filters and at varying times following the original activation. Analysis of such a series of autoradiographs permits the identification of a number of the pigments used in a painting, together with information about the manner in which they were originally laid down by the artist and their distribution throughout the body of the painting.Preliminary investigations have shown that the stability of oil paintings is unaffected by the activation procedure. The inherently necessary radiation dose absorbed by a painting as a result of activation sufficient for autoradiography is of the order of 50 rads. Paintings subjected to absorbed doses one hundred times as great as the dose necessary for autoradiography exhibit no changes in color, hardness, flexibility and solubility three years after their original activation. 相似文献
12.
AbstractA wide-ranging sample set consisting of dry pigments, dyed textiles, organic and aniline-based dyes, gouaches and watercolors, fluorescent inks, and natural history specimens was exposed to light in air (20.9% oxygen) and near-anoxic environments. After a light dosage of approximately 17.5 Mlux-hours under controlled temperature and humidity conditions, 113 of 125 samples (90% of the sample set) were shown to exhibit less color change in a low-oxygen environment compared with its behavior in air. Thirty-nine percent of this subset displayed color change in anoxia that was between two and four times lower than that observed in air, whereas 47% showed color change in anoxia reduced by a factor of four or more. In contrast, six samples exhibited greater color change in anoxia than in air – these samples included Prussian blue watercolor (three samples), Antwerp blue watercolor, Verdigris dry pigment, and Fluorescent Yellow Winsor & Newton Gouache. Although the results from this small sample subset may cause concern when considering the use of anoxia in the conservation of cultural heritage, particularly for colorant systems whose behavior in anoxia has not yet been identified, this study demonstrates the overwhelming benefits of anoxic light exposure for the vast majority of samples investigated here. 相似文献
13.
《The Reference Librarian》2013,54(79-80):297-309
Summary Chat reference is becoming prevalent in academic libraries across the country. This paper details the experience of East Tennessee State University's Sherrod Library when initiating such a service at their institution during the 2001-2002 academic year, which began as a response to the addition of a new online degree program in the state. Software selection, staff training, management issues, and statistical data are presented. Data analyzed includes use patterns, types of questions, and categories of users. The paper details librarians' reactions to providing reference services in this format, including the problems encountered. It also offers suggestions for a more successful implementation. 相似文献
14.
Light-induced color changes and chemical modification of treated and untreated chestnut wood surface
AbstractThe aim of this work is to study the surface modifications of chestnut (Castanea sativa Mill.) wood by reflectance spectrophotometry and Fourier transform infrared spectroscopy (FTIR) in order to understand the mechanisms that cause changes and to suggest possible solutions to avoid degradation phenomena. The experimental data were statistically treated to evaluate their significance. Concerning the surface protection of wood, starting from the results obtained by testing different commercial products, attention was focused on a novel organic preservative/consolidant product (Linfoil®) that has attracted great interest in the field of conservation of wooden artifacts. Color monitoring showed that wood surface color undergoes an important variation due to photoirradiation, occurring within the first 24 hours and mainly due to L* decrease and b* increase. Though the protective treatment modifies wood color, nevertheless the product tested seems to protect the wood surface by reducing photoyellowing. FTIR analysis indicated that irradiation caused the degradation of lignin and increased the concentration of the chromophore groups on the wood surface. Changes in the chromaticity coordinates can be linked to the degradation of lignin and to increase of the concentration of carbonyl groups. 相似文献
15.
《期刊图书馆员》2013,64(3):129-136
Abstract Analyzing serial issues of a monographic nature as a mechanism for connecting users to topical content has been a longstanding practice at the Iowa State University Library. Although studies have shown that monographic analysis of selected journal issues is a method of providing access to topical issues that citation databases often do not provide, the labor cost in providing original cataloging for some of these issues remains high. This article details the rationale and decision making that resulted in the implementation of a new process for reducing the amount of monographic analysis that is provided for uniquely titled journal issues. 相似文献
16.
《Communication monographs》2012,79(1):32-37
The following study details the procedure by means of which a Semantic Differential for use in investigations in the area of speech correction was developed. It is the third in a series of studies by the same author to appear in SM, the preceding two having dealt with general speech and the theatre arts, respectively. The three studies are similar in scope and content, defining the problems, demonstrating the methodology, and offering suggestions concerning possible applications of the measuring instruments. The author acknowledges that the studies are exploratory and the results tentative. He suggests that the Semantic Differential offers a new approach to certain dimensions of meaning in the speech area which have been slow to yield to older methods. 相似文献
17.
Finding an appropriate temporary storage location for books and providing access to them is a significant challenge for libraries undergoing renovations. The current article describes the use of a document management company by an academic library to store 430,000 books for 8 months and provide a retrieval-on-demand service. Aspects covered include the selection of a commercial storage provider with its own retrieval service; details of the move to and from offsite storage; the integration of the service with library processes; communications and user feedback; book usage during the storage period; overall costs; and lessons learned from the experience. 相似文献
18.
Donna R. Berryman 《Medical reference services quarterly》2013,32(3):271-279
AbstractThis article will help librarians understand how different philosophical stances influence the process of developing a research question and the different methodologies and methods available to help answer that question. Understanding this will help librarian researchers make appropriate choices regarding methods and methodology for the research questions they are seeking to answer. Also included is a table showing the two main types of inquiry (qualitative and quantitative) with their associated methodologies and methods, the basic assumptions underlying each, and the pros and cons of each methodology. 相似文献
19.
《文物保护研究》2013,58(1):95-97
AbstractAcrylic polymer dispersions, regularly used as artists' media or varnishes, were monitored for the development of yellow discoloration under natural aging conditions for a period of two years. Films of a number of water-based acrylic artists' media were kept under visible light of either moderate (150 lux) or low (50 lux) intensity (cycled on 10 hours per day) and were compared to films kept in dark storage, which have been observed to yellow. Results after two years show that exposure to visible light at 150 lux effectively prevented film discoloration in a number of products, and seemed at least to slow the rate of yellowing in others. Exposure to low-intensity (50 lux) lighting was found to be less effective in preventing this yellowing. 相似文献
20.
ABSTRACT Inter-Library Loan (ILL) service is one of the services provided by libraries that offers users a way to access library resources beyond their affiliated libraries. Additionally, it allows participating libraries to share and maximize their resources. This work examines the ILL process used by libraries in Singapore and proposes that the existing paper-based manual system be replaced by a Web-based ILL system. Such a Web-based system has been successfully designed and implemented at the Nanyang Technological University. The paper presents an overview of the system requirements and architecture, implementation details and demonstrates the feasibility and advantages of the new system. 相似文献