Integrated methodology for the evaluation of cleaning effectiveness in two Russian icons (16th–17th centuries)

This article covers a methodology for evaluating the effectiveness of cleaning two Russian icons. The icons belong to a group of five from the same iconographic school, dating from the 16th to 17th centuries. An integrated and complementary approach to varnish and overpaint removal involved microscopic techniques (optical and scanning electron microscopy) and colorimetry (CIE L*a*b* system). The materials and techniques used in these icons have been characterized previously. Cleaning revealed extensive overpainting that had not only dramatically changed the original appearance, but also the meaning and attribution of one of the two icons. The analyses carried out were useful in determining the extent of the overpainting and led to a better assessment of the results and effectiveness of the restoration. Microsc. Res. Tech. 73:752–760, 2010. © 2009 Wiley‐Liss, Inc.     

Implementation of spectroscopic techniques for characterization of icons of Deir El Sankoria,El Minia,Egypt

Four icons from church of Saint Theodore El Shatby, Deir El Sankoria, El Minia, Egypt, have studied by micro-destructive spectroscopic methods: Attenuated Total Reflection–Fourier Transform Infrared Spectroscopy (ATR–FTIR), Raman Spectroscopy (RS), Field Emission Scanning Electron Microscopy–Energy Dispersive X-ray Spectroscopy (FESEM–EDX), X-ray Photoelectron Spectroscopy (XPS) and Inductively Coupled Plasma–Optical Emission Spectroscopy (ICP–OES). This study gave information about the materials used in the icons painting, state of the icons, and evaluation of the effect of environmental conditions. ATR–FTIR and Raman methods showed the characteristic bands of lithopone and lead white as a ground material, gum Tragacanth as a binder, and chrome oxide green, mars yellow, mars red as a pigment. EDX microanalysis exhibited the elements of mars yellow and mars red pigments, and ICP–OES method showed the concentration of chromium element that is characteristic for chrome oxide green pigment. The results were authenticated by XPS method to ensure the materials used in the painting. SEM images showed the cracking of the paint surface. Degradation of the chemical structure of gum Tragacanth binder was attributed to metal oxides of the pigments in presence of sunlight and artificial light which led to promotion of the oxidation process and then deterioration of the painting through peeling of the painting surface and cracking of the paint film.     

Transmission electron microscopy applied to the study of works of art: sample preparation methodology and possible techniques

Technical examination of a work of art is a necessary preliminary stage both for proper conservation/restoration of the work and for purposes of dating and/or authentication. There is a wide variety of methods and procedures, and of these a particularly valuable technique is stratigraphic analysis in view of the data that it furnishes on the composition of the pictorial layers of which a painting is composed. The techniques utilized in this type of analysis to date have been essentially light microscopy and scanning electron microscopy. Transmission electron microscopy can provide new data for characterization of pictorial layers, thanks to the possibility of individually using ultrathin sections of paint sample. This study provides morphological analysis and microanalysis by X-ray energy dispersion, with determination of the crystalline structure of each particle by electron diffraction. The sample preparation method for producing thin sections from the pictorial layers for examination in the TEM is described. This allows the stratigraphic section to be preserved exactly as applied by the artist. The first results from the examination of three microsamples from actual old works of art are presented. The individual components of each strata were successfully identified in all cases.     

Assessment of cleaning effectiveness for new ecological systems on ancient tempera icon by complementary microscopy techniques

The study presents an old icon painted in egg tempera on lime wood, with a poor conservation condition and clogged dirt deposits. The icon is attributed to an anonymous painter of XIXth century and to the neo‐classical style of painting. The painting layer was done with only a hand full of pigments, earth colors that were often used in painting the icons from XVIIth to XIXth century in Eastern Europe, that have Byzantine influences. Taking into consideration the nature and the structure of the materials from the upper layers of the painting, affected by deposits of dirt over time, a series of cleaning recipes were studied, using the so called cleaning tests with compatible mixtures of different juices and infusion from indigenes plants, that were freshly done and odorless. A low alkaline 95% ethyl alcohol solution, combined with a few drops of ammoniac 25%, was used as a reference system, due to its compatibility with the greasy deposits found on the polychrome layer and on the wood. The cleaning capacity of the new systems used, in comparison with the standard solution, was analyzed through modern analytical methods of evaluating the degree of cleaning, more exactly by means of visible and UV reflectography, CIE L*a*b* colorimetry by reflection assisted by SEM‐EDX and IR spectroscopy. Microsc. Res. Tech. 77:1060–1070, 2014. © 2014 Wiley Periodicals, Inc.     

Fluorescence recognition of proteinaceous binders in works of art by a novel integrated system of investigation

Fluorescence microscopy and microspectrofluorometry are important tools in the characterization and identification of proteins, offering a great range of applications in conservation science. Because of their high selectivity and sensitivity, the combination of these techniques can be exploited for improved recognition and quantification of proteinaceous binders in paintings and polychromed works of art. The present article explores an analytical protocol integrating fluorescence microscopy and fluorometry for both identification and mapping of proteinaceous binders (in particular egg and glues) in paint samples. The study has been carried out on historically accurate reconstructions simulating the structure and composition of tempera and oil paints containing these binders. To assess the spatial distribution of specific proteins within the paint layers, cross‐sections from the reconstructions were analyzed by fluorescence imaging after staining with an exogenous fluorophore. Reference fluorescence spectra for each layer were acquired by a multichannel spectral analyzer and compared after Gaussian deconvolution. The results obtained demonstrated the effectiveness of the integrated protocol, highlighting the potential for the use of fluorescent staining coupled with microspectrofluorometry as a routine diagnostic tool in conservation science. The current work creates a set of fully characterized reference samples for further comparison with those from actual works of art. Microsc. Res. Tech., 2011. © 2011 Wiley Periodicals, Inc.     

A remote scanning Raman spectrometer for in situ measurements of works of art

In conservation science, one of the main concerns is to extract information from an artistic surface without damaging it. Raman spectroscopy has emerged in recent years as a reliable tool for the non-destructive analysis of a wide range of inorganic and organic materials in works of art and archaeological objects. Nevertheless, the technique is still mainly limited to the analysis of micro-samples taken from artistic surfaces. The development of an instrument able to perform non-contact analysis of an area of a few square centimeters aims to further increase the employment of this technique. This paper describes the development of a prototype Raman scanning spectrometer based on a diode laser, a 2D scanning mirror stage and a custom optical system, which can map a surface of 6 cm in diameter at a working distance of 20 cm. The device exhibits collecting optics with a depth of field close to 6 cm, which makes the Raman system suitable for the analysis of non-flat surfaces and three-dimensional objects. In addition, the overall dimensions and weight of the instrument have been limited in order to make the device transportable and, in principle, usable for in situ measurements. Details on the design of the device, with particular emphasis on the collecting optical system, and on results of the characterization tests carried out to assess its performances are reported. Finally, an example of an application involving the identification of pigments from a model painting is presented.     

旋杯式高速静电自动侧喷机与控制系统设计

旋杯式高速静电自动侧喷机是实现汽车车身表面喷涂的关键设备，本文在着重研究其工作原理和控制方法的基础上，设计开发了三自由度往复式侧喷机。该侧喷机采用先进的PLC控制器、转速控制卡和高压控制卡，能够实现伺服运动轴的准确定位和车身曲面仿形以及旋杯转速和静电高压的精确控制，并具有通过视窗化操作系统对喷涂过程进行实时监控的功能。实际应用结果表明，该控制系统工作稳定、可靠，喷涂效果满足工艺要求。     

Optimizing use of the structural chemical analyser (variable pressure FESEM‐EDX raman spectroscopy) on micro‐size complex historical paintings characterization

The novel Structural Chemical Analyser (hyphenated Raman spectroscopy and scanning electron microscopy equipped with an X‐ray detector) is gaining popularity since it allows 3‐D morphological studies and elemental, molecular, structural and electronic analyses of a single complex micro‐sized sample without transfer between instruments. However, its full potential remains unexploited in painting heritage where simultaneous identification of inorganic and organic materials in paintings is critically yet unresolved. Despite benefits and drawbacks shown in literature, new challenges have to be faced analysing multifaceted paint specimens. SEM?Structural Chemical Analyser systems differ since they are fabricated ad hoc by request. As configuration influences the procedure to optimize analyses, likewise analytical protocols have to be designed ad hoc. This paper deals with the optimization of the analytical procedure of a Variable Pressure Field Emission scanning electron microscopy equipped with an X‐ray detector Raman spectroscopy system to analyse historical paint samples. We address essential parameters, technical challenges and limitations raised from analysing paint stratigraphies, archaeological samples and loose pigments. We show that accurate data interpretation requires comprehensive knowledge of factors affecting Raman spectra. We tackled: (i) the in‐FESEM?Raman spectroscopy analytical sequence, (ii) correlations between FESEM and Structural Chemical Analyser/laser analytical position, (iii) Raman signal intensity under different VP‐FESEM vacuum modes, (iv) carbon deposition on samples under FESEM low‐vacuum mode, (v) crystal nature and morphology, (vi) depth of focus and (vii) surface‐enhanced Raman scattering effect. We recommend careful planning of analysis strategies prior to research which, although time consuming, guarantees reliable results. The ultimate goal of this paper is to help to guide future users of a FESEM‐Structural Chemical Analyser system in order to increase applications.     

新造货车涂装质量问题探讨

新造货车外涂油漆表面存在的质量问题主要表现为皱皮、剥离、漏涂、渣粒、流坠、桔皮等缺陷,除油漆本身原因外主要是涂装工艺和涂装管理差,故加强涂装前表面处理及涂装施工工艺方面的管理是解决油漆涂装质量问题的关键.     

粉末涂料在汽车涂装中的应用

介绍了粉末涂料的组成、优越性以及各种性能，分析了粉末涂料在汽车涂装中的经济性，肯定了粉末涂料在汽车工业中的应用前景。     

Regenerating titanium ventricular assist device surfaces after gold/palladium coating for scanning electron microscopy

Titanium is one of the most commonly used materials for implantable devices in humans. Scanning electron microscopy (SEM) serves as an important tool for imaging titanium surfaces and analyzing cells and other organic matter adhering to titanium implants. However, high‐vacuum SEM imaging of a nonconductive sample requires a conductive coating on the surface. A gold/palladium coating is commonly used and to date no method has been described to “clean” such gold/palladium covered surfaces for repeated experiments without etching the titanium itself. This constitutes a major problem with titanium‐based implantable devices which are very expensive and thus in short supply. Our objective was to devise a protocol to regenerate titaniumsurfaces after SEM analysis. In a series of experiments, titanium samples from implantable cardiac assist devices were coated with fibronectin, seeded with cells and then coated with gold/palladium for SEM analysis. X‐ray photoelectron spectroscopy spectra were obtained before and after five different cleaning protocols. Treatment with aqua regia (a 1:3 solution of concentrated nitric and hydrochloric acid), with or without ozonolysis, followed by sonication in soap solution and sonication in deionized water, allowed regenerating titanium surfaces to their original state. Atomic force microscopy confirmed that the established protocol did not alter the titanium microstructure. The protocol described herein is applicable to almost all titanium surfaces used in biomedical sciences and because of its short exposure time to aqua regia, will likely work for many titanium alloys as well. Microsc. Res. Tech., 2009. © 2009 Wiley‐Liss, Inc.     

浅谈静电喷涂中黑点缺陷的消除

静电喷涂技术具有喷涂雾化效果好和喷涂质量较高等优点,因而在汽车涂装生产中获得了广泛应用。但是,由于汽车漆大多采用金属漆,因此在应用过程中由于各种因素的影响,易出现各种涂装疵病。就汽车静电喷涂面漆时易出现的"黑点"问题进行探讨,找出产生的主要原因,并有针对性地提出有效的解决措施。     

Combination of normal light and fluorescence microscopy for authentication of five Lonicera species flower buds

The flower buds of five Lonicera species, Lonicera japonica Thunb., L. macranthoides Hand.-Mazz., L. hypoglauca Miq., L. confusa DC. and L. fulvotomentosa Hsu et S.C. Cheng are confusable and usually utilized under the same name "Jinyinhua" in different areas for morphological similarity. Studies found that these five species possess extreme differences in chemical compounds, correspondingly showing different pharmacological activities and clinical applications. To ensure efficacy and safety of these herbal medicines and prevent unknown adverse effect, in this work, a simple, rapid and effective method combining normal light and fluorescence microscopy was developed for authentication. Surface slides and transverse sections of these buds were investigated to reveal their differences. As a routine technique, normal light microscopy which gives detailed microscopic features such as glandular hairs and nonglandular hairs, can easily distinguish four species except L. confusa. Fluorescence technique, which could present different distribution of fluorescence materials, is further employed to identify three species including L. confusa successfully. It is the first report to identify these five Lonicera species by combining normal light and fluorescence microscopy. This work indicated combining normal light and fluorescence microscopy could be a powerful method in authentication of confused species.     

Micro‐fabrication and monitoring of three‐dimensional microstructures based on laser‐induced thermoplastic formation

This article reports a novel laser‐induced micro‐fabrication method and its monitoring system for three‐dimensional (3D) microstructures. The mechanism of the method is that a small zone of thermoplastic material melted by laser heating grows in liquid surrounding environment, solidifying into a convex microstructure, such as micro‐dot or micro‐pillar. A laser diode (808 nm) with maximum power output of 130 mW is used as power source, and a kind of paraffin mixed with stearic acid and paint serves as the thermoplastic material for 3D microstructure formation experiments. A light microscope system consisting of a charge‐coupled device (CCD) and a computer is utilized to realize real‐time observation of the micro‐fabricating process. The distribution of local temperature rise on material surface created by laser irradiation is simulated. The effects of liquid environment on microstructure formation have been theoretically analyzed and experimentally studied. Experiments are further carried out to investigate the relationship between laser spot and fabricated microstructures. The results indicate that the widths of micro‐dots or micro‐pillars are mostly determined by the size of focal spot, and their heights increase with the enlargement of laser power density. With this method, a micro‐dot array of Chinese characters meaning “China” has been successfully fabricated through computer programming. This method has the advantages of implementing direct, mask‐less, real‐time and inexpensive 3D microstructure fabrication. Therefore, it would be widely applied in the fields of micro/nano‐technology for practical fabrication of different kinds of 3D microstructures. Microsc. Res. Tech., 2009. © 2009 Wiley‐Liss, Inc.     

Inline electron holography and VEELS for the measurement of strain in ternary and quaternary (In,Al,Ga)N alloyed thin films and its effect on bandgap energy

We present the use of (1) dark‐field inline electron holography for measuring the structural strain, and indirectly obtaining the composition, in a wurtzite, 4‐nm‐thick InAlGaN epilayer on a AlN/GaN/AlN/GaN multinano‐layer heterosystem, and (2) valence electron energy‐loss spectroscopy to study the bandgap value of five different, also hexagonal, 20–50‐nm‐thick InAlGaN layers. The measured strain values were almost identical to the ones obtained by other techniques for similarly grown materials. We found that the biaxial strain in the III‐N alloys lowers the bandgap energy as compared to the value calculated with different known expressions and bowing parameters for unstrained layers. By contrast, calculated and experimental values agreed in the case of lattice‐matched (almost unstrained) heterostructures.     

数据采集中的动态口令身份认证研究

静态身份认证系统以明文形式进行消息交换,数据采集系统采用此认证方式,用户口令极易被窃取和泄漏,为提高数据采集系统的安全性,针对数据采集系统的特点,设计了一个基于"挑战/应答"的动态口令身份认证系统,并研究了动态口令技术,对当前数据采集系统的安全风险进行了分析以及对系统的结构组成和功能进行了阐述,并对系统的安全性进行了剖析.该系统克服了传统口令认证容易被窃取的弱点,解决了企业数据采集系统的用户身份认证的安全问题.     

Automated tool trajectory planning of industrial robots for painting composite surfaces

Automatic trajectory generation for spray painting is highly desirable for today’s automotive manufacturing. Generating paint gun trajectories for free-form surfaces to satisfy paint thickness requirements is still highly challenging due to the complex geometry of free-form surfaces. In this paper, a CAD-guided paint gun trajectory generation system for free-form surfaces has been developed. The system utilizes the CAD information of a free-form surface and a paint gun model to automatically generate a paint gun trajectory to satisfy the paint thickness requirements. Complex surfaces are divided into patches to satisfy the constraints. A trajectory integration algorithm is developed to integrate the trajectories of the patches. The paint thickness deviation from the required paint thickness is optimized by modifying the paint gun velocity. A paint thickness verification method is also developed to verify the generated trajectories. The results of simulations have shown that the trajectory generation system achieves satisfactory performance. This trajectory generation system can also be applied to generate trajectories for many other CAD-guided robot trajectory planning applications in surface manufacturing.     

Contributions of scanning electron microscopy to the assessment of the effectiveness of stone conservation treatments

The efficiency of 16 products (with consolidating and/or water‐repellency effects) applied to granites and limestones have been assessed by means of scanning electron microscopy (SEM). The technique offers the possibility of observing the porous system of the stone, the products' filming capacity, the penetration depth of the products into the stone, their distribution on the porous system, and their conservation degree through time. Scanning electron microscopy has to be considered as complementary to some other tests and techniques to assess the efficiency of conservation treatments, such as stone‐water contact angle, water vapour permeability, and global colour variations, among others. The conclusion reached is that the SEM technique defines some of the parameters, properties, and characteristics that highly control the efficiency of the treatments. This work confirms the SEM technique, particularly using backscattering electrons, as a very useful and complementary tool to assess the efficiency of the conservation treatments applied to stone materials for restoration purposes.     

高温分解除漆工艺在再制造过程中的应用研究

再制造的过程是传统生产的逆向过程,其毛坯为废旧产品和服役年限终止的产品。旧零件表面油漆的处理是工艺的难点,带油漆旧件拆解后第一道工序是旧件的油漆层的去除。通过对旧件油漆处理方法进行研究,采用高温分解除漆工艺,通过高温把零件上旧油漆在高温下裂解,再通过清洗等工序清洗去除油漆分解后的残留有机物,既达到了除漆目的又不会对被去除零件本身性能造成影响,实现旧零件油漆层的去除。     

Is fast mapping good mapping? A review of the benefits of high‐speed orientation mapping using electron backscatter diffraction

Orientation mapping using automated electron backscatter diffraction (EBSD) is now a common technique for characterizing microstructures. Improvements in software and hardware have resulted in high‐speed mapping capabilities above 80 000 points h^?1. For ‘routine’ microstructural analyses of materials such as steel and aluminium (e.g. texture and grain size measurements and high angle boundary characterization), high‐speed orientation mapping is an ideal approach with minimal penalty on the final statistics. However, for the accurate analysis of very low angle boundaries and for routine analyses of more difficult materials (e.g. most rock samples), we advocate a more patient approach to orientation mapping with an emphasis on data accuracy and reliability. It is important that the objectives of any EBSD analysis are carefully considered before starting – in this way the maximum potential of an EBSD system can be achieved.