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Article

23 April 2024

Visible Light-Driven H2O2 Photoelectrocatalytic Synthesis Over a Tandem Electrode Strategy

Photocatalytic synthesis of hydrogen peroxide (H2O2) can be an environmentally friendly and energy-saving solution. However, the oxygen reduction reaction (ORR) rate is limited due to the low solubility of O2 in water. In this study, a modified BiVO4 (BVO) photoanode combined with an Sn-coordinated phthalocyanine gas diffusion electrode (SnPc-GDE) was employed for the synthesis of H2O2, and the oxy-gen reduction reaction rate was increased through a unique three-phase interface system. When visible light was irradiated on the BVO photoanode, the hole-electron pairs were excited and the oxygen evolution reaction (OER) was driven through the holes, and the excited electrons were transferred to the SnPc-GDE to reduce O2 for the synthesis of H2O2. Oxygen vacancy enrichment on the BVO electrode was achieved by photoetching and annealing under an N2 atmosphere, which effectively improved the carrier separation efficiency. Complexation with a WO3 layer formed a built-in electric field, which further promoted the electron-hole pair separation. The SnPc catalyst-modified GDE electrode has the best selectivity for ORR and remains stable during long-term reactions. Under bias-free conditions, the generation rate of H2O2 reached 952.5 μM·L−1·h−1, with a Faradaic efficiency of 48.4%. This study provided a practical strategy for designing a highly efficient BVO/SnPc-GDE photoelectrochemical system to produce H2O2 based on improvement in electron-hole transmission efficiency and product selectivity.

Keywords: BiVO4; Oxygen vacancy; Gas diffusion electrode; O2 reduction reaction; H2O2 production

Article

22 April 2024

Paleo-Asian Cultural Phenomena of Ancient Beringia: Population Convergence and Solution of Ethnic Self-Identification

Authors offer for a discussion the materials from studies of archaic culture elements that include body modifications in ethnic groups in the context of population genetic data from native peoples of the Far North. The authors consider materials from the territory of ancient Beringia which include a part of Chukotka and Kamchatka in Russia, Alaska in the USA and several island groups in between. The working hypothesis of the study involves the identification of common and specific features of body modifications in ethnic groups having similar population genesis. This allows to clarify the specifics of the regional contacts. Body modifications (tattoos, piercings, etc.) are considered as a way of a person’s self-identification and a form of his group membership (in this case—ethnic group). The study used ethnographic, archaeological, paleo-history, folklore materials and up-to-date data that include genetic research of contemporary ethnic groups inhabiting the territory of ancient Beringia and maintaining their traditional way of life. The methodology base of the research is based on formalized approach and cross-cultural analysis evidence of the similarity/difference of the population in combination with the method of comparative analysis of DNA data and information about their genetic structure.

Keywords: Pacific North; Aleuts; Eskimos; Chukchi; Genetic data; Ethnic people; Tattoos; Cross-cultural analysis

Article

22 April 2024

Construction of a Comprehensive International Legal Protection Mechanism for Climate Refugees

Climate refugee has become an unavoidable major right crisis challenge for the international community. However, the corresponding development of positive international law is obviously imperfect. The basic rights of climate refugees cannot be fully guaranteed by international law. They are always facing problems such as unclear legal status lack of protection of basic rights, and imperfect relief mechanism. Those vulnerable groups who lack resources and migration abilities suffer more serious rights violations because they are forced to stay in place. Compared with the risk-management framework and right-protection framework, the comprehensive international legal protection mechanism is the inevitable choice for climate refugees’ rights relief in the post-2012 period. The rights of climate refugees set out in the preamble of the Paris Agreement in 2015, the New York Declaration on Refugees and Migrants in 2016, the Global Refugee Compact in 2018, and the Global Compact for Security, Order and Regular Migration formally incorporated the issues of refugees and migrants caused by climate change, laying the foundation for this choice. However, it is a long and difficult way to build a perfect comprehensive international response to climate change. It is not only necessary to realize the integration of human rights law and climate law at the conceptual level, but also to integrate the different perspectives of the two laws and build a set of scientific and reasonable cooperation mechanism.

Keywords: Climate refugee; Human right law; Climate law; Refugee law; Comprehensive legal protection mechanism

Article

19 April 2024

Can Digital Village Construction Reduce Rural Income Disparity?—Empirical Analysis Based on Inter-provincial Panel Data in China

Cutting the income disparity within rural areas is one of the key priorities in seeking common prosperity in China. Based on the panel data of 20 provinces in China from 2011 to 2020, we empirically analyze the impact of digital village construction on rural income disparity by building a digital village construction level indicator system which represents three dimensions of digitalization in rural areas, i.e., digitalization of rural infrastructure, digitalization of agricultural development and digitalization of rural residents’ life. Overall, the level of digital village construction in rural China has shown a development trend of gradual improvement, while the development level in various regions is unbalanced and varies greatly. The results of the fixed-effect model show that, digital village construction can significantly reduce the income disparity in rural areas, whereas the effect is significant in eastern China, insignificant in central and western China. It is recommended to increase the investment in funds and talents and take full consideration and advantage of local conditions, while promoting the development of new rural digital economy, so to achieve the development goal of common prosperity of rural residents.

Keywords: Digital village construction; Rural income disparity; Rural revitalization

Comment

19 April 2024

Article

18 April 2024

Biodegradable Composite Materials Based on Cassava Starch and Reinforced with Topinambur (Helianthus tuberosus) Aerial Part Fiber

The cultivation of topinambur (Helianthus tuberosus) has aroused the interest of producers since it is a source of inulin and can be used for biofuel production. During tuber processing, the aerial part of the crop remains as a by-product with no practical application. This work aimed to characterize the fibers obtained from the aerial part of topinambur and to evaluate their reinforcing potential in cassava starch-based films. Starch-based films with topinambur fiber (0, 5, and 10%) were prepared by extrusion followed by thermocompression. Topinambur residue contains 88.6% of total fiber, 8.5% ash, and 0.68% lipid. Mechanical film properties evidenced the reinforcement action of topinambur fiber, 10% content was able to increase up to 70% the Young’s modulus. SEM micrographs evidenced the good fiber-matrix interaction. UV-visible capacity, opacity, and chromaticity parameters of TPS films increased with fiber content in the formulation. Fiber incorporation improved the hydrophobicity of the biocomposite materials by increasing the contact angle. Starch-based films biodegraded more than 55% after 110 days, showing a similar trend to that of microcrystalline cellulose. Thus, topinambur residue can be effectively used as a reinforcing agent for TPS materials, being an innovative and non-toxic additive within the circular economy premises.

Keywords: Biodegradable materials; Thermoplastic starch; Reinforcing agent; Topinambur residue; Agriculture

Article

17 April 2024

Thermogravimetric Study of the Oxidation Behavior of the Cantor’s Alloy at 1000 °C and Beyond

A polycrystalline Cantor alloy, equimolar in Co, Cr, Fe, Mn and Ni, was cast. It was subjected to oxidation in a thermo-balance in a flow of synthetic dry air, at 1000, 1050, 1100 and 1150 °C. The mass gain was globally parabolic but rather irregular. The parabolic constants, ranging from 55 to 700 × 10−12·g2·cm−4·s−1, are much higher than for a chromia-forming alloy. They obey an Arrhenius law with an activation energy equal to 270 kJ/mol. The external oxide scales formed are composed of an outer part made of manganese oxide and an inner part made of (Cr, Mn) oxide containing a thin internal layer of chromia. The Mn and Cr-depleted depths and the Mn and Cr masses lost by the alloy increase with the oxidation temperature. Cr-rich acicular particles precipitated in subsurface at 1100 °C and internal oxidation along the grain boundaries are present in the whole thickness of the sample oxidized at 1150 °C. Oxide spallation occurred during the cooling, at temperatures in the 200–350 °C range, only for the alloys oxidized at 1050 and 1100 °C. Not too thick scale (1000 °C) or deep internal oxidation (1150 °C) may be favorable for scale adherence.

Keywords: Cantor alloy, Equiatomic CoCrFeMnNi composition, Elevated temperatures, Thermogravimetry follow-up, Kinetic analysis, Metallographic characterization

Editorial

17 April 2024

Review

15 April 2024

Human Mobility in the Central and Eastern Mediterranean during Hellenistic and Roman Times: The Potential and Limitations of Bioarchaeological Research

This paper offers a review of bioarchaeological research on human mobility during the Hellenistic and Roman period in the Central and Eastern Mediterranean. This period was marked by significant connectivity amidst the establishment of major political entities. The paper begins with an overview of bioarchaeological methods used to study past mobility, including biodistance, isotopic and ancient DNA analyses. It then examines published studies that have utilized these methods to explore mobility during the Hellenistic and Roman periods. The paper concludes by critically assessing the current research limitations and proposing directions for future studies. These suggestions emphasize the importance of conducting additional research to investigate human mobility in neglected areas, as well as at different temporal and spatial scales. Integrating mobility data with other sources of evidence, such as historical accounts, paleoenvironmental data and osteobiographic information is another important future direction of research. Finally, relevant research should be more theoretically informed and its contemporary implications should be effectively communicated within and beyond the academic community. An enhancement of our understanding of the nature and impact of mobility is crucial in today’s society, where misconceptions linking immigration to the decline of the Roman Empire can perpetuate biases against contemporary mobility. 

Keywords: Paleomobility; Isotopes; Ancient DNA; Biodistance; Greco-Roman

Article

15 April 2024

Impacts on the Legal Framework for Protecting Environmental and Human Rights in Brazil due to Ideological Antagonism: The Interrelated Cases of the Yanomami and the Amazon Fund

The occupation of the Amazon is driven by capitalist production, impacting climate change discussions. Despite constitutional protections since 1934, the influx of non-Indigenous settlers, particularly miners, led to significant conflicts. The Yanomami sought international recourse through the Inter-American Commission on Human Rights (IACHR). In the context of redemocratization, the 1988 Constitution marked a shift, reinforcing Indigenous rights and environmental protection. Brazil’s role in protecting the rainforest intersects with global climate efforts, including the REDD+ mechanism. The creation of the Amazon Fund in 2008, aligned with REDD+ initiatives, involved international cooperation and local governance, leading to a substantial decline in Amazon deforestation between 2004 and 2012. However, exploitative practices endorsed by the State pose threats to environmental and human rights, notably affecting indigenous communities. Amid Brazil’s democracy crisis, deforestation surged in the Amazon from 2013–2022 and the Yanomami face conflicts fueled by State support for non-Indigenous groups. The Yanomami sought international recourse through the IACHR and the Inter-American Court of Human Rights. These issues are intensified by an ideological bias, linked to authoritarian populism rooted in the legacy of the Dictatorship. Recent initiatives aim to enhance environmental and human rights protection. However, political instability poses challenges for the future.

Keywords: Amazon; Brazil; Yanomami; Amazon Fund; Democracy; Authoritarian Populism
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