Egyptian blue pigment in East Mediterranean wall paintings: A study of the lifetime of its optical infrared emission

This study presents advances in the application of laser‐based methods to image and measure the luminescence lifetime of historical wall paintings containing Egyptian blue. Samples from Tel Kabri, a major Canaanite palace dated to 18th C. BCE, from the Roman city of Caesarea Maritima, from the 4–5th C. Byzantine tomb in Lohamei HaGeta'ot, and from a 6th C. Byzantine church of Shivta have been studied using time‐resolved photoluminescence spectroscopy and imaging. Taking into account the high sensitivity of the emission lifetime to the microenvironment surrounding the emitting species, here, we show for the first time that the optical emission from historical samples containing Egyptian blue particles exhibits meaningful lifetime variations. Indeed, the wall paintings from Tel Kabri, Lohamei HaGeta'ot, and Shivta present the shortest emission lifetime, close to 115–120 μs. However, samples from Caesarea Maritima wall paintings exhibit a different optical emission, which dumps more slowly with an average lifetime of 130 μs. Egyptian blue pigment particles, synthetised with modern methods, are associated with the longest emission lifetime of 147 μs. This study suggests that there is a possible link between the lifetime of the pigment's emission and its synthesis method.     

Dc leakage currents in trichloroethylene oxides

Undoped silicon dioxide is compared to oxide in which trichloroethylene (TCE) was used during growth. The gate leakage currents in MOS transistors are examined. It is shown that a reduction in the leakage current occurs in TCE oxides. A novel measurement technique is employed to examine the gate leakage currents of the MOSFETs.     

Analysis of protein-based media commonly found in paintings using synchronous fluorescence spectroscopy combined with multivariate statistical analysis

The spectrofluorimetric analysis of protein-based binding media, which are commonly found as painting materials, is based on the detection of emissions from amino acids, as well as fluorescent degradation products that develop with aging. Laser-induced fluorescence spectroscopy, fluorescence excitation emission spectroscopy, and time-resolved fluorescence spectroscopy have all been employed in efforts to discriminate between commonly found proteinaceous binding media, including egg white, egg yolk, milk, and casein, as well as collagen-based glues from rabbit skin, ox bone, parchment, and fish. However, synchronous fluorescence spectroscopy (SFS), a rapid means of recording fluorescence properties of samples, has not been reported for the differentiation between binding media. This work focuses on the analysis of a large set of naturally aged films of different protein-based binding media using SFS with a range of different offsets between excitation and emission monochromators between 30-60 nm. An interpretation of synchronous fluorescence spectra of binding media is presented and is followed by an assessment and classification of a database of recorded spectra using multivariate analysis. Importantly, following SFS analysis of films of binding media, principal component analysis is used to differentiate among all the proteinaceous media considered on the basis of clustering of data. This application is thus a novel and nondestructive means for differentiation between protein-based binding media.     

Synchrotron UV-Visible Multispectral Luminescence Microimaging of Historical Samples

UV-visible luminescence techniques are fre-quently used for the study of cultural heritage materials, despite their limitations for identification and discrimination in the case of complex heterogeneous materials. In contrast to tabletop setups, two methods based on the vacuum ultraviolet (VUV)-UV-visible emission generated at a bending magnet of a synchrotron source are described. The main advantages of the source are the extended wavelength range attained, the continuous tunability of the source, and its brightness, leading to a submicrometer lateral resolution. Raster-scanning microspectroscopy and full-field microimaging were implemented and tested at the DISCO beamline (synchrotron SOLEIL, France). Investigative measurements were performed on a sample from a varnished musical instrument and a paint sample containing the pigment zinc white (ZnO) in order to illustrate some of the challenges analyzing heterogeneous cultural heritage cross-section samples with the novel imaging approach. The data sets obtained proved useful for mapping organic materials at the submicrometer scale and visualizing heterogeneities of the semiconductor pigment material. We propose and discuss the combined use of raster-scanning microspectroscopy and full-field microimaging in an integrated analytical methodology. Synchrotron UV luminescence appears as a novel tool for identification of craftsmen's and artists' materials and techniques and to assess the condition of artifacts, from the precise identification and localization of luminescent materials.     

Ultimate loads for eccentrically loaded model shallow strip footings on geotextile-reinforced sand

A series of tests were carried out with an eccentrically loaded model surface shallow strip footing on reinforced dense sand to investigate the decrease of the ultimate loads with increasing eccentricity and to compare the experimental results with commonly used approaches such as Meyerhof's effective width concept and the customary analysis. An experimental system was produced and used to run the tests. The experimental system consists of a tank, model footing, sand, loading mechanism, etc. A single woven geotextile sheet was placed horizontally below the footing's base at a depth of half of the footing's width. Geotextile reinforcement increased ultimate loads when compared to the unreinforced cases. This contribution decreases with increasing eccentricity. The measured decreases in ultimate loads with increasing eccentricities in the unreinforced tests within the core (kern, middle third) are in good agreement with Meyerhof's approach, while customary analysis is a little on the conservative side. Outside the core, Meyerhof's approach is on the conservative side in this case. Decreasing ultimate loads with increasing eccentricity for the reinforced tests cases were in general agreement with customary analysis, although they are slightly greater.     

The knowledge and practice of food safety by young and adult consumers

Each year, millions of people worldwide suffer from food-borne diseases and illnesses. Therefore, food-related infection is an important health problem in many countries. The study was conducted in Ankara Province of Turkey to determine food safety and food preparation practices of young and adult consumers. The sampling group was composed of randomly-selected 646 young and 815 adult individuals and questionnaires were applied with face-to-face interviews made between April and December, 2006. It was discovered that food safety knowledge of young consumers is at an insufficient level and their practices are inappropriate. It was also revealed that there is a significantly meaningful difference between the food safety knowledge and food preparation practice scores of young and adult consumers in favor of adult consumers (P < 0.001).     

Synthesis of bisphenol a novolac epoxy resins for coating applications

Bisphenol A novolacs were synthesized in both melting and solution processes using p‐formaldehyde and formalin solution in presence of oxalic acid catalyst, respectively. Hydrogen nuclear magnetic resonance, ¹H NMR, investigations show a high methylene bridge contents in the novolacs synthesized in a melting process. These novolacs were analyzed by gel permation chromatography (GPC) and fourier transform infrared spectroscopy (FTIR). The bisphenol A novolac was cured with 1‐(2‐amino ethyl) piprazine (AEP) as a curing agent for epoxy resins. The cured resins were evaluated as organic coating for steel. The mechanical properties of the cured epoxy resins were evaluated. The chemical resistances of the cured resins were evaluated through salt spray resistance, hot water, solvents, acid and alkali resistance measurements. The data indicate that the cured epoxy resins have excellent chemical resistances as organic coatings among other cured resins. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Numerical Investigation of the Transient Heat Transfer of a Blood Shipping Box

In this study, the design of a blood reservoir is implemented by numerical simulation of the transient heat transfer in the reservoir. The blood is considered to be kept at constant temperature in a flat, multi-compartment cylindrical reservoir under hot air temperature. A commercial phase-change media (PCM) (CaCl₂ · 6H₂O) and insulation materials are employed to keep the blood at a constant temperature. The parametric values in this study are the type and thickness of the insulation material and the thickness of the PCM layer. Two types of low-density insulation material are analyzed (extruded polystyrene and glass fiber). The thickness of the extruded polystyrene ranged from 0.25 cm to 1 cm, and the thickness of the PCM layer was varied from 1.5 cm to 2.5 cm.     

Housing Market Renewal in Liverpool: Locating the Gentrification Debate in History,Context and Evidence

This paper places the Housing Market Renewal programme in Liverpool in its historical context, highlighting a mismatch between the supply and demand for housing which has existed for four decades. This disequilibrium produced an environment where successive waves of neighbourhood abandonment occurred from the late 1970s despite significant public policy interventions. The implementation of the Housing Market Renewal programme has stimulated a debate about the extent to which the public sector interventions are leading to the gentrification of poor neighbourhoods. The paper finds that there is no evidence of gentrification in older neighbourhoods, however, inflows of capital rather than middle-class residents have altered the physical development of the city to an extent that the housing choices of all income groups have been affected. The paper concludes that critical gentrification research should take account of historical development and wider housing market change to remain relevant to the debate about the changing social and economic structure of cities.     

Development and validation of a multilevel safety climate measurement tool in the construction industry

Construction organizations are large and complex with decentralized structures, and characterized by non-routine work undertaken by semi-autonomous work groups. Construction workers’ perceptions of safety climate can form at different levels and vary between subunits. A multilevel safety climate measurement tool was proposed, which identified five important safety agents, i.e. client, principal contractor, supervisor, co-workers, and individual workers. Surveys were conducted at three construction projects commissioned by Fonterra Co-operative Group. A total of 356 participants completed the survey. The data was subject to scale reliability analysis and factor analysis. The results showed that all scales achieved satisfactory internal consistency and the multilevel factorial structure was generally supported. At the organizational level, the tool measures clients’ overall safety priority and safety actions, and principal contractors’ general commitment to safety. At the group level, the tool measures supervisors’ safety actions and safety expectations, and co-workers’ general safety values and practices. The tool also measures individual safety responses reflected by safety compliance and safety participation. The measurement tool would help construction organizations to diagnose potential weaknesses in their safety management practices for safety improvement and also help to develop a social and cultural work environment that is supportive of safety at all levels.