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The European Union (EU) is moving towards sustainable development, and a key role is played by circular economy (CE) models geared towards reducing pressure on natural resources, generating jobs and fostering economic opportunities. Indicators are able to aggregate a variety of information and their use, through the use of multi-criteria decision analysis (MCDA), allows the performance of alternatives to be monitored. This work aims to calculate the performance of the EU27 in the years 2019 and 2020 according to 15 CE indicators available on Eurostat. The results of the Analytic Hierarchy process show that the greatest impact on circularity is determined by the category ‘competitiveness and innovation’, which together with the category ‘global sustainability and resilience’ accounts for two thirds of the overall weight. The MCDA results show that Belgium prevails in both the baseline and alternative scenarios, ahead of Italy and the Netherlands respectively. In general, circular policies see western European countries excel, while the performance of eastern European countries is weaker. The implications of this work highlight the three main barriers to the development of CE models: (i) illegal waste management; (ii) lack of knowledge and low level of investment in circular technologies and (iii) low distribution of value among stakeholders. In this way, resource management based on circularity will enable Europe to meet the challenges of sustainability with less dependence on imported raw materials.

In this study, we report the experimental findings of a multi-methodological and comparative investigation of a natural (from the Wah Wah Mountains of Beaver County, Utah) and three synthetic (hydrothermally grown) gem-quality red beryls by means of: gemmological standard testing, laser ablation inductively coupled mass spectroscopy, infrared and Raman spectroscopy, ultraviolet–visible–near infrared absorption spectroscopy, and single-crystal X-ray diffraction. Gemmological, crystallo-chemical, and spectroscopic features of the natural and synthetic stones enabled us to unveil the causes of their color (from red, to purplish-red, or orange-red) and how different and complementary techniques can be efficiently used to discriminate between natural and synthetic materials, based on non-destructive, micro-destructive, and destructive techniques.

Agates from Yozgat province are appreciated on the gem market for their white and purple-blue banded colours. In this study, we present a detailed investigation aimed at the identification of the atomic and structural origin of this peculiar colouration of chalcedony. X-ray diffraction and Raman spectroscopy revealed the presence of fine grains of quartz and moganite with a preferential accumulation of the latter in the blue bands. Near-infrared diffuse absorption spectra show overtones of hydroxyls vibrations at 1425, 1900, and 2250 nm. In the visible, the broad absorption at about 500 nm, as well as its behaviour at low temperatures, is compatible with the optical activity of iron impurities in quartz matrices, such as that observed in amethysts. Peak intensities and shapes are very similar for spectra collected in blue and white bands. Accordingly, trace-element composition from laser ablation inductively coupled mass spectrometry confirmed that the two regions have similar Fe content. The perceived changes in band colours are indeed originated by differences in microstructural arrangement and size of the grains visualised through scanning electron microscopy. White and blue stripes have grains of about 5 µm and 300 nm in size, respectively, resulting in an accentuated scattering component for the white bands. Therefore, the unique purple-blue shades typical of Yozgat agates are a combination of iron-related colour centres and scattering effect.

Agates from Yozgat province are appreciated on the gem market for their white and purple-blue banded colours. In this study, we present a detailed investigation aimed at the identification of the atomic and structural origin of this peculiar colouration of chalcedony. X-ray diffraction and Raman spectroscopy revealed the presence of fine grains of quartz and moganite with a preferential accumulation of the latter in the blue bands. Near-infrared diffuse absorption spectra show overtones of hydroxyls vibrations at 1425, 1900, and 2250 nm. In the visible, the broad absorption at about 500 nm, as well as its behaviour at low temperatures, is compatible with the optical activity of iron impurities in quartz matrices, such as that observed in amethysts. Peak intensities and shapes are very similar for spectra collected in blue and white bands. Accordingly, trace-element composition from laser ablation inductively coupled mass spectrometry confirmed that the two regions have similar Fe content. The perceived changes in band colours are indeed originated by differences in microstructural arrangement and size of the grains visualised through scanning electron microscopy. White and blue stripes have grains of about 5 µm and 300 nm in size, respectively, resulting in an accentuated scattering component for the white bands. Therefore, the unique purple-blue shades typical of Yozgat agates are a combination of iron-related colour centres and scattering effect.

In this study, we report the experimental findings of a multi-methodological and comparative investigation of a natural (from the Wah Wah Mountains of Beaver County, Utah) and three synthetic (hydrothermally grown) gem-quality red beryls by means of: gemmological standard testing, laser ablation inductively coupled mass spectroscopy, infrared and Raman spectroscopy, ultraviolet–visible–near infrared absorption spectroscopy, and single-crystal X-ray diffraction. Gemmological, crystallo-chemical, and spectroscopic features of the natural and synthetic stones enabled us to unveil the causes of their color (from red, to purplish-red, or orange-red) and how different and complementary techniques can be efficiently used to discriminate between natural and synthetic materials, based on non-destructive, micro-destructive, and destructive techniques.

AbstractThe value chain refers to the source of competition to facilitate organizations to maximize and sustain value for their consumers. Value chain flexibility is necessary to build sustainable initiatives in addressing ambiguity. In the literature, there is a lack of framework to highlight the challenges to sustainable initiatives in value chain flexibility. This study fills this research gap by suggesting a framework for challenges to sustainable initiatives in value chain flexibility. In this study, thirteen potential challenges to sustainable initiatives in value chain flexibility are identified and an integrated model is developed. It adopts the modified Total Interpretive Structure Model and the Cross-Impact Matrix Multiplication Applied to Classification methodology. The mixed approach is used as the modified Total Interpretive Structure Model organizes the binary interactions among the challenges, while Cross-Impact Matrix Multiplication Applied to Classification analysis organizes specific precise assessments of the driving power and dependence of the challenges. The results of the study reflect that (i) lack of supplier commitment to sustainable products and (ii) lack of knowledge toward sustainability in value chains are the challenges that achieved the highest driving power. The challenge ‘inadequate communication among the suppliers in the value chain’ is at the highest level in the analysis. The proposed framework could help government and non-government bodies to formulate policies to efficiently address challenges to sustainable initiatives in value chain flexibility.

AbstractThe value chain refers to the source of competition to facilitate organizations to maximize and sustain value for their consumers. Value chain flexibility is necessary to build sustainable initiatives in addressing ambiguity. In the literature, there is a lack of framework to highlight the challenges to sustainable initiatives in value chain flexibility. This study fills this research gap by suggesting a framework for challenges to sustainable initiatives in value chain flexibility. In this study, thirteen potential challenges to sustainable initiatives in value chain flexibility are identified and an integrated model is developed. It adopts the modified Total Interpretive Structure Model and the Cross-Impact Matrix Multiplication Applied to Classification methodology. The mixed approach is used as the modified Total Interpretive Structure Model organizes the binary interactions among the challenges, while Cross-Impact Matrix Multiplication Applied to Classification analysis organizes specific precise assessments of the driving power and dependence of the challenges. The results of the study reflect that (i) lack of supplier commitment to sustainable products and (ii) lack of knowledge toward sustainability in value chains are the challenges that achieved the highest driving power. The challenge ‘inadequate communication among the suppliers in the value chain’ is at the highest level in the analysis. The proposed framework could help government and non-government bodies to formulate policies to efficiently address challenges to sustainable initiatives in value chain flexibility.

Several gem corals, belonging to the classes Hydrozoa and Anthozoa of the phylum Cnidaria, have been analyzed. These have been previously classified from a zoological point of view. In this paper surface structures, physical data, FTIR- and Raman-spectra of corals with gem potential have been investigated. Spectrophotometric characterisation proved to be a useful tool for determining the main features of the mineral phases (calcite or aragonite) and of the organic content in each sample. Chromophore complexes belonging to the caroteno-proteins of the carotenoid family also could be detected.