Green Earth Research Articles

Heterogeneous Photocatalysis: A Solution for a Greener Earth

Since the beginning of the industrial era, various human activities have steadily increased, leading to rapid technological developments and high population growth [...]

A Study on Correggio Wall Paintings: Characterization of Technique and Materials of Abbey Church of S. Giovanni Evangelista in Parma, Italy

This study deals with the materials of the sub-arch painting of the Del Bono Chapel of the Abbey Church of S. Giovanni Evangelista in Parma, Italy, datable to around 1523. The artist is Antonio Allegri, known as Correggio (1489–1534), who is considered to be one of the greatest painters of the 16th century. Micro-Raman spectroscopy, micro-Fourier transform infrared spectroscopy and gas chromatography coupled with mass spectrometry were used as the main techniques to identify the pigments and binding media. The analysis enabled us to identify the pigments which were characteristic of the epoch. Correggio’s palette was composed by mineral pigments—sometimes expensive ones such as lapis lazuli, azurite and cinnabar—together with a wide range of earths, or by synthetic pigments like smalt blue. From the amino acid content determination, it was shown that, in the samples containing lazurite, smalt, hematite, green earth and goethite, the protein fraction was attributable to the presence of a mixture of egg and animal glue, from which the use of the a secco technique could be assumed, with pigments that did not need organic binding media on the wall. For the gilding sample, the study found that Au foil had been applied on a brown background (oil-based missione).

A Multi-Analytical Investigation of Roman Frescoes from Rapoltu Mare (Romania)

(1) Background: Due to the precarious situation of many monuments or archeological sites, analytical investigations are necessary to obtain information about the used materials, as well as to identify the most appropriate solutions for their conservation/restoration. This paper addresses the characterization of mural painting fragments collected during the excavation in 2018 in Rapoltu Mare (La vie), Deva. (2) Methods: Specific analytical techniques were used, as follows: X-ray diffractometry (XRD), wavelength dispersive X-ray fluorescence (WDXRF), optical microscopy (OM), zoom microscopy and scanning electron microscopy (SEM), spectroscopic techniques (UV–Vis, FTIR, Raman), porosity and thermal analysis, all of which provide information about the structure, chemical composition, morphology and topography of pigments and their deterioration as well. (3) Results: Up to seven different pigments were identified: Egyptian blue, carbon, calcite, gypsum, hematite, goethite and green earth. Egyptian Blue is identified in all the other color areas, except the white area: in the green zone (as degradation product with beeswax) and in the red zone (in mixture with ochre) too. In addition, carbon and beeswax were highlighted as toner and binder for pigments, respectively. In the presence of the organic beeswax binding environment, the Egyptian blue pigment particles darkened or turned yellow significantly, changing the blue to a greenish color. It is also possible to identify wollastonite (CaSiO3) in the blue pigment, which indicates that the temperature used in the manufacturing of Egyptian blue was higher than 950 °C from thermal analysis. The presence of apatite, hematite and gypsum deposits in the Hunedoara region certifies that these pigments could have been of local origin, as demonstrated by the presence of analytically identified elements (Fe, P, S, Ca). (4) Conclusions: The analytical techniques used for such investigations have highlighted the main pigments used in Roman times for various Roman murals.

MD simulation/Quantum chemical calculations and experimental studies of Ranunculus bulbosus biomolecules impact on the mild steel dissolution reduction in a destructive acidic liquid

Owing to the movement toward greener earth, this study is a small contribution to this global process. The current research selected the Ranunculus bulbosus (RB) molecules in order to evaluate whether its extract could impart a corrosion-preventive quality to the MS attribute in the HCl condition. To reach this point, some distinct, as well as related tests, were performed. FESEM and AFM confirmed the positive impact of RB extract (RBE) upon the microstructure; the RBE addition considerably smoothened the surface in contrast with the sample doped with no RBE. UV–Vis showed the presence of several functional groups on the surface; while GIXRD provided the reason for the possible complexation of RBE molecules with Fe. Raman test confirmed the presence of inhibitor molecules on the surface via analyzing the carbon-based structures' existence. EIS was used for the corrosion-related analysis, and the increment of inhibitor concentration to 2000 ppm in company with 5 h of drowning time maximized the potency of corrosion resistance to 94%. Also, the corrosion-preventive performance of the RBE was supported by potentiodynamic polarization tests. RBE adsorbed over the surface via Langmuir regulation. Quantum chemical calculations based on the density functional theory (DFT) and molecular dynamics (MD) simulation have delivered helpful information regarding electron transfer and mechanism during adsorption of inhibitor ingredients on the mild steel surface. MD simulation revealed the interaction of inhibitors molecules and surface in addition to their high coverability. Also, DFT results suggested that electron sharing could occur between inhibitors molecules as metallic surfaces. In the end, the comparison of other studies with the current one was provided, and the mechanism was discussed.

Investigation on the Painting Materials and Profile Structures Used in Ancient Chinese Folk Architectural Paintings by Multiple Analytical Methods

In order to understand the painting materials and profile structures used in the creation of Chinese ancient folk architectural paintings, the architectural paintings of the Bell and Drum Tower at Fushan Temple in Shaanxi Province of China was investigated. In this study, optical microscopy, Fourier transform infrared spectroscopy (FTIR), micro-Raman spectroscopy, scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS), and chemical experimental methods were used. The profile structures, and the elemental and chemical compositions of the pigments and binders in the ground layer of the 12 samples were determined. Results showed that the painting profile structures in both towers comprised of pigment layer, underpainting layer and ground layer, where no starch was found in the chalk ground layer. The pigment layer mainly comprised of iron oxide red, chalk, lapis lazuli, carbon black, green earth, and a dark green pigment that is formed by a combination of carbon black and green earth. To-date, the use of green earth pigment in Chinese architectural paintings was not found in Chinese related academic literature; hence, this study marked the first identification of green earth being used in the architectural paintings. Tung oil, commonly used in Chinese architectural paintings as a binder for pigment, was also identified in the samples. Results from this study will serve as an important reference for better scientific investigation methods on ancient Chinese folk painting materials.

Development of cement composite with high-temperature detection performance using green earth

This study proposed cement composites with natural green earth to detect elevated and abnormal temperatures. The thermochromic properties of the green earth pigment were examined with increasing temperature, and mixed cement composites were designed based on the pigment content and elevated temperatures. Cement composites with a pigment content of at least 3% demonstrated an irreversible color transition from grayish green to brown. The transition range of the temperature and the change in RGB values depended on the pigment content The color transition ranged from 250° to 350°C for specimens with pigment contents of 3% and 6% and from 200° to 300°C for specimens with a pigment content of 9%. In addition, the specimens with pigments showed a significant drop in weight between 200 and 250 °C, followed by a gradually decreasing rate similar to that of the control specimen. The change in the compressive strength at room temperature was minimal, regardless of the pigment content in the cement composites. After subjected to elevated high temperatures, the compressive strength was reduced by approximately 31.4% for the control specimen and 53.2% for specimens with pigments. The pigment content had minimal effect on the loss of strength.

A Game Theory Approach Using the TLBO Algorithm for Generation Expansion Planning by Applying Carbon Curtailment Policy

In the present climate, due to the cost of investments, pollutants of fossil fuel, and global warming, it seems rational to accept numerous potential benefits of optimal generation expansion planning. Generation expansion planning by regarding these goals and providing the best plan for the future of the power plants reinforces the idea that plants are capable of generating electricity in environmentally friendly circumstances, particularly by reducing greenhouse gas production. This paper has applied a teaching–learning-based optimization algorithm to provide an optimal strategy for power plants and the proposed algorithm has been compared with other optimization methods. Then the game theory approach is implemented to make a competitive situation among power plants. A combined algorithm has been developed to reach the Nash equilibrium point. Moreover, the government role has been considered in order to reduce carbon emission and achieve the green earth policies. Three scenarios have been regarded to evaluate the efficiency of the proposed method. Finally, sensitivity analysis has been applied, and then the simulation results have been discussed.

Green Bills for Green Earth: How the International Trade and Climate Regimes Work Together to Save the Planet

Through their Intergovernmental Panels on Climate Change, the scientific community tells us that we are heading towards a climate catastrophe. As a result, various countries are offering various promising and novel policy instruments to mitigate climate change and continue to grow macroeconomically, as we witnessed in the Glasgow Conference of the Parties in 2021. In other words, finding ways to grow economically while, at the same time, protect the environment and mitigate climate change. In that spirit, this article first provides an overview of the global trade and climate regimes. It then offers an analysis of how the World Trade Organization (WTO) globally and the European Union (EU) regionally might combat climate change in remarkable ways. The article also provides an analysis of European Green Deal and the US Green New Deal (GND), two encouraging policy instruments to help mitigate climate change ambitiously. Finally, the article provides a thorough assessment of the EU’s Carbon Border Adjustment Mechanism (CBAM). European Green Deal, US Green New Deal, Carbon Border Adjustment Mechanism, carbon pricing, GATT general exceptions, non-discrimination principle in GATT

Performance of a HAWT Rotor with a Modified Blade Configuration

As the world focuses more on clean and green Earth, wind energy plays a significant role. Wind energy is a renewable source of energy that can cope with the ongoing global fossil fuel crisis. The wind energy converters like wind turbines have been studied a lot in terms of design and performance. The current work includes analyzing the output effects of a horizontal axis wind turbine (HAWT) with a modified blade configuration at specific wind speeds. A numerical investigation is carried out using two different numerical software on the chosen airfoil used in blade design validated with the analysis carried out in open-loop wind tunnels. The study is divided into two phases: first, the selected airfoil is tested experimentally and using CFD, and then the findings are compared to those of the University of Illinois Urbana Champaign wind tunnel tests at low Reynolds numbers. The second phase includes the numerical analysis based on the blade element momentum method and non-linear lifting line simulations of modified blade design at high Reynolds number. The numerical results of rotor performance analysis have been compared to existing experimental results. The findings of all numerical investigations agree with those of the experiments. An optimal value of the power coefficient is obtained at a particular tip speed ratio close to the desired value for large wind turbines. For maximum power, this study investigates the optimum pitch angle. The work demonstrated the improved HAWT rotor blade design to produce better aerodynamic lift and thus improve performance.

Corporate Social Responsibility and Football Clubs: The Value of Environmental Sustainability as a Basis for the Rebranding of Real Betis Balompié in Spain

On October 2020, Real Betis Balompié, a football club located in Seville (Andalucia), presented the Forever Green programme, a global programme of Corporate Social Responsibility (CSR) that, through the club’s foundation, enables the entity to position itself in areas of sustainable development and environment at a global level. This project was preceded by a sponsorship initiative with the Green Earth project, as well as having been the first football club to sign the United Nations’ Climate Change Now initiative. This article aims to explain the rebranding process of a sports brand based on values linked to sustainability and to assess the impact this rebranding process has had on the fans’ perception of the brand. The methodology used was a combination of in-depth interviews with the executives charged with leading the rebranding process and a convenience survey given to 100 fans to assess the impact of the initiative. The results show that both the entity and the fans agree on a holistic vision of what the CSR is, altruistic in nature, and that its initiatives should be applicable across the entire organisation. However, although the club’s link with values of the environment and sustainability is highly valued by the fans, they still do not feel directly called upon to take part in actions that the club organises.

Connecting Rheological Properties and Molecular Dynamics of Egg‐Tempera Paints based on Egg Yolk

AbstractEgg‐tempera painting is a pictorial technique widely used in the Middle Ages, although poorly studied in its physico‐chemical aspects until now. Here we show how NMR relaxometry and rheology can be combined to probe egg‐tempera paints and shed new light on their structure and behavior. Based on recipes of the 15th century, model formulations with egg yolk and green earth have been reproduced to characterize the physicochemical properties of this paint at the mesoscopic and macroscopic scales. The rheological measurements highlight a synergetic effect between green earth and egg yolk, induced by the interactions between them and the structural organisation of the system. 1H NMR relaxometry emphasizes the presence and the structure of a network formed by the yolk and the pigment.

Connecting Rheological Properties and Molecular Dynamics of Egg-Tempera Paints based on Egg Yolk.

Egg-tempera painting is a pictorial technique widely used in the Middle Ages, although poorly studied in its physico-chemical aspects until now. Here we show how NMR relaxometry and rheology can be combined to probe egg-tempera paints and shed new light on their structure and behavior. Based on recipes of the 15th century, model formulations with egg yolk and green earth have been reproduced to characterize the physicochemical properties of this paint at the mesoscopic and macroscopic scales. The rheological measurements highlight a synergetic effect between green earth and egg yolk, induced by the interactions between them and the structural organisation of the system. 1 H NMR relaxometry emphasizes the presence and the structure of a network formed by the yolk and the pigment.

Adopting the Features of Digital Rate Shaping (DRS) with Multiple Injections Strategy on Small 2 Cylinder Common Rail BSVI Engine to Improve FE

<div class="section abstract"><div class="htmlview paragraph">The Common Rail fuel injection System (CRS) has completely changed the whole diesel engine combustion cloud dynamics and enhanced the applicability of diesel engines further with a motto of providing a more cleaner sky and greener earth. The most cutting-edge technological developments made in CRS and EGT system enables OEMs to achieve further more stringent emission norms and adopt the environmental protection compliances.</div><div class="htmlview paragraph">Today’s CRS systems are the most advanced generation fuel injection systems providing further high injection pressures, wide multiple injections capability with shorter dwell periods enabling real smoother Digital Rate Shaping (DRS) and injection control that benefits not only the engine combustion performance but also enables smarter thermal management of modern exhaust systems while meeting stringent emission compliances and achieving future CO2 reductions goal.</div><div class="htmlview paragraph">Initial DRS developments were tried with a dwell period up to 800us-500us with limitations over injector durability. Later with the advances in FIE technology the dwell periods could further be reduced to 500us-200us. The recent technologies developed are capable of reducing dwell period -100us or further lower within the boundary conditions of system application limits.</div><div class="htmlview paragraph">In this paper, an experimental study on the application of multiple injections coupled with an intelligent adoption of such DRS features are studied on 2 Cylinder Common Rail BSVI engine in order to improve engine part load BSFC performance and on road FE in vehicle city driving conditions.</div><div class="htmlview paragraph">Preliminary DoE trials conducted on engine test bed for the selected load collective points (in part load engine operating zones identified from vehicle driving cycle) shown benefit over conventional CRS (non DRS) technology.</div><div class="htmlview paragraph">Results show that, DRS strategy improves overall engine BSFC by 4.3% without having any additional friction reduction or energy saving gazettes on engine.</div><div class="htmlview paragraph">The MIDC emission test results with this strategy shows a reduction in CO2 emissions and fuel consumption by -4% over conventional strategy.</div></div>

Micro‐Raman spectroscopy for the analysis of materials found in rock art shelters in Piedra Parada valley, Chubut province, Argentinian Patagonia

AbstractMicro‐Raman spectroscopy was employed for the analysis of samples collected from the shelters Campo Cerda 1, Angostura Blanca and Campo Moncada 1 located in Piedra Parada valley, Chubut province, Argentinian Patagonia. Different coloured layers, degradation products and rock supports were analysed. Haematite (α‐Fe2O3), goethite (α‐FeOOH), green earth and gypsum (CaSO4 ·2H2O) were responsible for the main colouration of the pigmented layers together with other components. Gypsum, Ca‐oxalates and calcite were the major degradation materials affecting the rock paintings and the rock support. Different types of silicates, apatite [Ca5(PO4)3(F,Cl,OH)] and goethite were positively characterized in the rock support. Point analysis and micro‐Raman mappings contributed towards a better understanding of the materials and layer sequencing of the samples extracted.

Multi-Scale Characterization of Unusual Green and Blue Pigments from the Pharaonic Town of Amara West, Nubia

Pigments from paint palettes and a grindstone excavated from the pharaonic town of Amara West (c. 1300–1050 BCE), which lies between the Second and Third Cataracts of the Nile, were examined using polarized light microscopy, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction, and scanning electron microscopy with energy dispersive X-ray spectroscopy. Most of the pigments were consistent with the typical ancient Egyptian palette, but the greens and some blues were unusual. Two types of green pigment were identified, chlorite (varieties clinochlore and penninite) and copper chloride hydroxide (atacamite type). The former constitutes a type of green earth which has only rarely been identified in pharaonic Egyptian contexts and may be more widespread than is currently reported. The majority of the blue pigment samples were Egyptian blue, but some were found to be a blue earth, the main component of which being sodic amphibole riebeckite. The use of this mineral as a pigment has not previously been reported in any Nile Valley context. These results prompt questions around local and potentially indigenous practices within an ancient colonial context, and highlight avenues for future research.

The ecology and bioactivity of some Greco-Roman medicinal minerals: the case of Melos earth pigments

Mineral compounds, as pigments and therapeutics, appeared regularly in the technical and medical texts of the Greco-Roman (G-R) world. We have referred to them as ‘G-R medicinal minerals’ and we suggest that despite their seeming familiarity, there are actually many unknowns regarding their precise nature and/or purported pharmacological attributes. Earth pigments are part of that group. This paper presents a brief overview of our work over the past twenty years relating to: a. the attempt to locate a select number of them in the places of their origin; b. their chemical/mineralogical characterization; c. the study of their ecology via the identification of the microorganisms surrounding them; d. their testing as antibacterials against known pathogens. In the process, and to fulfil the above, we have developed a novel methodological approach which includes a range of analytical techniques used across many disciplines (mineralogy, geochemistry, DNA extraction and microbiology). This paper focuses on a select number of earth pigments deriving from the island of Melos in the SW Aegean, celebrated in antiquity for its Melian Earth, a white pigment, and asks whether they might display antibacterial activity. We demonstrate that some (but not all) yellow, green and black earth pigments do. We also show that the manner in which they were dispensed (as powders or leachates) was equally important. The results, although preliminary, are informative. Given their use since deep time, earth pigments have never lost their relevance. We suggest that the study of their ecology/mineralogy and potential bioactivity allows for a better understanding of how our perception of them, as both pigments and therapeutics, may have evolved.

The dome of Rotunda in Thessaloniki: Investigation of a multi-pictorial phase wall painting through analytical methods

The present study focuses on the investigation of the successive pictorial phases of the wall painting which survives on the missing eastern part of the magnificent mosaic composition in the interior of Rotunda, Thessaloniki, Greece. Rotunda, a circular domed monumental building, was constructed in the early 4th century AD and it is included in the UNESCO World Heritage List. Characterization analysis was performed by means of microscopic, spectroscopic and crystallographic techniques, in order to identify the technological features of the wall painting and the materials used, to document the initial Byzantine pictorial phase -known from the archaeological research- along with the overpaintings attributed to the 19th and 20th centuries. In this framework, the collected samples were studied with optical microscopy, Fourier transform infrared micro-spectroscopy, scanning electron microscopy, X-ray diffractometry and X-ray photoelectron spectroscopy. Among the detected materials and pigments (including zinc oxide, barium sulfate, red lead, green earth, Prussian blue, emerald green, ultramarine and cuprite), the use of brass powder for false gilding purposes was detected, which is a material rarely used for mural applications.

Spectroscopic analysis of pigments in a wall painting from a high Roman Empire building in Córdoba (Spain) and identification of the application technique

Fragments of a wall painting from a High Roman Empire building in Córdoba, southern Spain, were examined. The aim was not to extract archaeological information, but rather to precisely identify the materials from which the pigments were obtained and how they were applied. The mortar receiving the pigments was also analysed. Determinations were done by using X-ray fluorescence (XRF), micro-Raman (μ-Raman) and Fourier transform infrared (FT-IR) spectroscopies, X-ray diffraction (XRD) and scanning electron microscopy coupled to energy dispersive X-ray spectroscopy (SEM–EDS). The XRF technique allowed chemical elements to be identified and, in combination with SEM–EDS, their spatial distribution in the fragments to be elucidated. Similarly, μ-Raman spectroscopy and XRD allowed the chemical species in the mortar to be identified. The pigments found were typical of the Roman colour palette used in Hispania and included various types of ochre (yellow and red), mixtures containing green earths, white (calcium carbonate), black (carbon) and precious materials such as cinnabar and Egyptian blue. The mortar was found to have been prepared in the traditional manner from limestone and sand. The pigments were applied in solution or suspended in lime water, a technique that was latter named mezzo fresco. By exception, cinnabar and Egyptian blue were applied with the secco technique and the aid of an organic binder. Some fragments contained several paint layers. In any case, the paint was invariably applied directly on an unprimed wall.

Calcium antimonate: A new discovery in colour palette of Paestum wall paintings

During a restoration and diagnostic campaigns carried out on Paestum funerary slabs belonging to the Lucanian funerary art, calcium antimonate (CaSb2O6) was detected for the first time in the pictorial layers. This artificial pigment, widely employed as opacifier both in ancient glass and glaze covering clay objects, was found in the wall paintings, regardless of the colour, supporting the hypothesis of an intentional addition of calcium antimonate to the pigments and the involvement of ceramic painters.A multi-analytical approach was performed on 32 funerary slabs (6th – 3rd century BCE), currently located at the National Archaeological Museum of Paestum (Italy) using both polarized light microscopy and environmental scanning electron microscopy equipped with energy dispersive X-ray spectrometer, micro X-ray fluorescence, micro Raman spectroscopy, Fourier Transform Infrared spectroscopy and powder X-ray diffraction.The results confirmed the use of a limited number of pigments, usually applied with fresco technique, although in many cases the stratigraphy of the painted layer showed morphology of mezzo fresco technique, but no organic binders were found. The hues of vegetal decorations were obtained using green earth, sometimes Egyptian blue mixed with yellow ochre, carbon and bone blacks, and orpiment. The alteration of green earth and other iron-containing pigments are likely responsible for the discolouration of the original hues. In red paints, hematite and red ochre are frequently associated with ilmenite, a typical volcanic mineral. Egyptian blue was used in blue paints while in black paints it was mixed with carbon and bone black pigments.

Green and blue pigments in Roman wall paintings: A challenge for Raman spectroscopy

AbstractIn Roman wall paintings, blue and green colours are less commonly encountered than red and yellow and were more expensive. Despite this, Pliny and Vitruvius describe the more common compounds used for these pigments, translated today as azurite, lazurite, chrysocolla, indigo and Egyptian blue for blues and verdigris, malachite, celadonite, glauconite and chlorite for greens. A confusion in their nomenclature is often found in the most common blue pigment that is the first manufactured compound, Egyptian blue. For greens, celadonite and glauconite were usual and called generically ‘green earths’, but they prove to be difficult to characterize analytically. In this paper, we evaluate the Raman spectroscopic identification of the characteristic Roman blue and green pigments as used in wall paintings using two different laser wavelengths (green and near infrared) and clarify their nomenclature.