34 research outputs found

    Corrosion stratifications on glass jewellery excavated beneath the market square in Kraków, Poland

    Get PDF
    Glass has been one of the materials selected for its decorative purposes since early mankind. Its production was complex and varied all around the world, considering the sources of local materials used for its production as well technological knowledge about the manufacturing process. The aim of this work is to put some light on glass jewelry unearthed during the archeological excavations at the Main Market Square in Kraków, and to increase the importance of a stratifications investigation of ancient subjects by induced corrosion, using glass sensors.The collected data helps to determinate the definitive condition of a historical object. This data will also help to establish the chemical nature of the corrosion products and the altered glass and metal surfaces. Moreover, the ring presented in this work can be considered to be from a small group of fine medieval jewelry corresponding to the upper class of the population, such as the nobility or wealthy merchants. Such individuals dealt with the exchange of goods with foreign countries. Because of a very limited amount of analytical material, only nondestructive analysis: scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS), X-ray diffraction (XRD), X-ray fluorescence spectrometry (XRF), glass sensors were applied. The glass and metal have been tested separately

    Influence of environment on the corrosion of glass–metal connections

    Get PDF
    'Glass sensors' of the eighteenth century Backer glass and the sixteenth century enamel from Limoges have been chosen for a series of experiments. Combinations of these materials with different base materials such as copper and bronze has been investigated. To create surface changes on the 'glass sensor', a corrosion process was induced in a controlled environment. A variety of corrosive agents such as hydrochloric acid, sulfuric acid, water and formaldehyde were used. The sample immersed in the corrosive solution was exposed alternately to light and high temperature for a total of 38 weeks. During this period, macroscopic and microscopic observations were made and series of tests such as SEM/EDS and Raman spectroscopy were performed on the surface of the samples. ICP-MS methods were used to determine the change in the chemical composition of the solutions where the samples had corroded. The primary aim of this study was to identify the impact of a number of external corrosive variables such as temperature, humidity and local environment to identify the most damaging environments for glass–metal objects. The obtained results showed the chemical and physical phenomena acting on the surface of the glass, metal or in the place of their joints. Information obtained on this study was used to explain the influence of the environment on the surface of glass–metal materials. Results can be used in the design of conservation work as well as for sustainable conservation

    The Psychological Science Accelerator's COVID-19 rapid-response dataset

    Get PDF

    The psychological science accelerator’s COVID-19 rapid-response dataset

    Get PDF
    In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data

    A global experiment on motivating social distancing during the COVID-19 pandemic

    Get PDF
    Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

    A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic.

    Get PDF
    The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about a situation. Participants from 87 countries and regions (n = 21,644) were randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing) or one of two control conditions (active or passive). Results revealed that both reappraisal interventions (vesus both control conditions) consistently reduced negative emotions and increased positive emotions across different measures. Reconstrual and repurposing interventions had similar effects. Importantly, planned exploratory analyses indicated that reappraisal interventions did not reduce intentions to practice preventive health behaviours. The findings demonstrate the viability of creating scalable, low-cost interventions for use around the world

    Analysis of cross-sectional layers of corrosion using metallographic microscope

    No full text
    Tyt. z nagłówka.Bibliogr. s. 131-132.The aim of this study was to identify and recognize the phenomena of corrosion between glass-metal connections. Experiments were carried out on historical and contemporary samples treated with corrosion catalysts and the results helped to identify the most corrosive conditions for historic objects. Microscopic observations were carried out on cross-sectional layers of specially prepared samples of enamel on copperplate, corresponding to the chemical composition of historic samples-enamel from Limoges. Subsequently, a series of techniques were implemented improving the quality of the image. A 20-micron thick corrosion layer can be observed and recorded using this method. Observations allowed to determine the quality and technology aspects of the enamel exposed to the processes. The diagnosis of corrosion processes is extremely important in order to determine the application technique of enamel on the metal substrate. Microscopic images therefore revealed the formation of corrosion products. This proved an efficient and effective way to provide information on the thickness, color and structure of the observed layers. Micro-photographs from a metallographic microscope allowed for further planning and the subsequent use of a Scanning Electron Microscope (SEM) with an Energy Dispersive Spectrometer (EDS) and Raman Spectrometer (RS) - mitigating the need for the analysis of the entire sample's surface. Most corroded places have been identified and the metal proved to be more reactive material. The impact of factors such as: the technique of layering the enamel, structural inclusions, pitting corrosion, temperature and the environment's impact have been clearly linked to the overlap of the corrosion processes.Dostępny również w formie drukowanej.KEYWORDS: corrosion, enamel on copperplate, glass-metal, corrosion build-up, metallographic microscope, cross section of corrosion products

    Quantitative determination of ammonium salts in organo-zeolites by infrared spectroscopy abstract /

    No full text
    Tyt. z nagłówka.Art. jest abstr. referatu z konferencji.Bibliogr. s. 132.In recent years, the feasibility of using fly ash from the combustion of coal for the synthesis of zeolites has been studied (Belviso et al. 2010, Derkowski et al. 2010). One of the many uses of zeolites is to leverage their properties to act as organic sorbents (Bowman 2003). Unfortunately, the sorption process of organic substances on zeolites is hampered by the negatively-charged surface of the crystallites (Jashua & Bowman 2009). In order to increase the chemical affinity of the zeolite's surface to the organic molecules, its modification by organic surfactants is necessary. This leads to the formation of an organo-mineral complex with improved sorption properties. It has been found that organo-zeolites may be used to remove volatile compounds in a pure form, and those which occur in nature as impurities of air, water and soil (Damjanovic et al. 2010, Vidal et al. 2012). Therefore, it seems reasonable to search for an organo-zeolite sorbent which is cheap, efficient and environmentally-friendly (Apreutesei et al. 2008). The zeolites modification takes place only on the outer surface of the crystallites as the ammonium salts' molecules are too large to enter the zeolite's channels. Therefore, external cation exchange capacity (ECEC) is an important property in the synthesis of organo-zeolites. The type of surfactant introduced and its amount, often given by ECEC values, is crucial-subsequently leading to the formation of materials differing in sorption properties. Thus, it is essential to determine the effectiveness of modification by examining the amount of surfactant adsorbed on zeolites' surface. In the experiments, a Na-P1 zeolite synthesized from fly ash remaining after coal combustion and a natural Ukrainian zeolite were transformed into organo-zeolites. This involved the replacement of original exchangeable cations (K+, Na+, Ca2+, Mg2+) by organic cations from the following salts: hexadecyltrimethylammonium bromide (HDTMA) and octadecyltrimethylammonium bromide (ODTMA) in amounts equal to 0.25, 0.50, 0.75 and 1.00 of ECEC. ECEC for synthetic zeolite Na-P1 was determined, and it was 24.4 meq/100 g, which corresponds to a single layer (1.0). The aim of this study was to use the infrared spectroscopy (FTIR) to determine the quantity of the surfactant adsorbed on the crystallites surface. The FTIR spectra were collected by a Thermo Scientific Nicolet 7600 spectrometer using the DRIFT technique. The CHN analysis was used to investigate the modification efficiency through quantification of the attached surfactant. The normalized intensity of selected bands attributed to C-H stretching vibrations in the 3,000-2,800 cm-1 region was compared with CHN results. The results revealed a high correlation (R2 > 0.99) between spectroscopic and chemical analyses. The band intensities compared with the efficiency of modification enabled to obtain appropriate calibration curves. This proved that FTIR could be used for a fast determination of the surfactants amount in the obtained organo-zeolites.Dostępny również w formie drukowanej.KEYWORDS: fly ash, combustion, coal
    corecore