Environmental Problems Research Articles

Structural forming of soil composites using as a pavement subgrade strengthening

The article substantiates the possibility of obtaining composite materials with improved functional properties to strengthen the subgrade, containing technogenic soil stabilized by an additive based on a gelling polymer. The introduction of technogenic soils into composites will not only reduce the consumption of expensive materials, but also solve a complex of acute environmental problems. Composite materials can be used in the construction of structural layers of road pavements, foundations of buildings and structures, sites for various purposes, for the prevention and elimination of defects in the foundations of engineering structures during their construction, reconstruction and repair, including in permafrost areas. Stabilized technogenic soils are more durable, frost-resistant and waterproof, which makes them applicable for creating impervious curtains in hydraulic structures and sealing storage facilities for hazardous substances. The cryogenic effect on a composite material allows one to vary its properties within a wide range and modify its macroporous structure. Studying the process of structure formation of the resulting organic-inorganic materials, consisting of macromolecules of high-molecular substances and inorganic inclusions that have undergone cryogenic treatment, will make it possible to specifically regulate their performance characteristics. The best values of strength characteristics were obtained for samples with a stabilizing additive concentration of 100g/l. The resulting composite materials are hydrophobic, frost-resistant, characterized by a compressive strength of 2.3-6.5MPa and a thermal conductivity of 0.19-0.20W/(m·K). Data from differential scanning calorimetry and thermogravimetry and IR spectroscopy revealed that the binding of mineral particles by a stabilizing additive occurs due to the formation of organomineral complexes with the participation of clay minerals and the restructuring of hydration shells. SEM data indicate that crystallinity zones formed due to hydrogen bonds of hydroxyl groups of neighboring polymer chains can participate in the formation of the composite structure. An increase in the number of cryogenic treatment cycles promotes additional structuring and strengthening of the polymer phase due to the formation of additional nodes of the supramolecular network, ordering of crystallinity zones and the appearance of compacted areas in the structure. Computed X-ray tomography revealed an increase in the density of the composite upon drying, which helps to increase its strength characteristics. The structure of the sample is characterized by heterogeneity of the pore space, which is characterized by the presence of both fine-porous and large-porous regions, which determines its thermophysical properties.

In Ukrainian

An important environmental problem is the removal of contaminants and the purification of domestic and industrial water from pollutants of various nature. There is a separate issue of cleaning the effluents of pharmaceutical enterprises. Various chemical and physical methods are used to solve these problems, such as settling, coagulation, filtration, and sorption techniques. Adsorption with using efficient and reusable adsorbents is the most effective and cheap. In recent years special attention has been paid to the use of sorption materials based on hydrolysis lignin, which has a high sorption activity in relation to ions of some heavy metals, dyes, organic compounds and pharmaceuticals. The use of lignin as an adsorbent simultaneously solves two problems: the disposal of paper production waste and the purification of sewage from various types of pollutants. The aim of this work was to study the sorption properties of hydroylysis lignin in aqueous solution in relation to some medical substances of different chemical nature, existing in solution in cationic, anionic or neutral forms. The point of zero charge of hydrolysis lignin was determined, which is equal to рНPZC = 4.95. The adsorption of rivanol, proflavin, doxorubicin, levofloxacin, furacilin, and salicylic acid by hydrolysis lignin was studied as dependence on the pH of the solutions and the concentration of adsorbates. It was found that adsorption largely depends on the structure of the pharmaceuticals and the pH values of the solutions. It is shown that the studied medical compounds, which exist in the solution in the form of cations, are adsorbed the best (rivanol, proflavin, doxorubicin). Adsorption of these substances occurs mainly due to electrostatic interaction with negatively charged surface groups. Adsorption of anionic form (salicylic acid) is the smallest and is observed only at quite low pH values. Levofloxacin is adsorbed mainly in the form of zwitter ions, and furacilin is in neutral form. The adsorption of these both compounds occupies an intermediate value of adsorption amount. The obtained adsorption isotherms are well lined up in Langmuir coordinates. Quantitative parameters of adsorption values - of maximum adsorption and equilibrium constants were calculated. Quite high values of these parameters indicate that hydrolysis lignin can be used as an adsorbent for the removal of these pharmaceuticals.

Highlighting the importance of biodiversity conservation through the Holy Qur'an.

Religious environmentalism relies upon religious texts and leadership to promote effective and long-lasting change for environmental problems, such as responsible use and conservation of natural resources and biodiversity. World religions note the importance of biodiversity and humanity's responsibility in stewarding biodiversity as a member of ecological communities. We reviewed Quranic verses that relate to biodiversity and align with United Nations Sustainable Development Goals (SDGs). The Holy Quran was reviewed in electronic and hard copy formats, and verses related to biodiversity were translated to English and tabulated by Qur'anic chapter, verse, and narrative citation. Twenty-one Qur'anic verses were identified that addressed biodiversity. Scriptures were divided into 5 groups that addressed provision of resources, governance or stewardship of resources, nature as a teacher, and human life in nature's communities or described creation of biodiversity. Qur'anic verses were aligned with 4 SDGs (goals 12-15), which address sustainable consumption of natural resources, global climate change, life in marine environments, and life in terrestrial environments, including freshwater ecosystems. This alignment demonstrates the interconnectedness of life, that conservation of biodiversity is referenced in the Quran, and how positive management of natural recourses can be beneficial to Muslim communities on local, national, and global scales. Positive movement toward ecofriendly practices, sound environmental resource use and management, biodiversity conservation, and governmental policies on conservation can be promoted through scriptures from the Holy Qur'an.

The effect of extracellular polymeric substances on MICP solidifying rare earth slags and stabilizing Th and U.

Microbially induced carbonate precipitation (MICP) has been used to cure rare earth slags (RES) containing radionuclides (e.g. Th and U) and heavy metals with favorable results. However, the role of microbial extracellular polymeric substances (EPS) in MICP curing RES remains unclear. In this study, the EPS of Lysinibacillus sphaericus K-1 was extracted for the experiments of adsorption, inducing calcium carbonate (CaCO3) precipitation and curing of RES. The role of EPS in in MICP curing RES and stabilizing radionuclides and heavy metals was analyzed by evaluating the concentration and morphological distribution of radionuclides and heavy metals, and the compressive strength of the cured body. The results indicate that the adsorption efficiencies of EPS for Th (IV), U (VI), Cu2+, Pb2+, Zn2+, and Cd2+ were 44.83%, 45.83%, 53.7%, 61.3%, 42.1%, and 77.85%, respectively. The addition of EPS solution resulted in the formation of nanoscale spherical particles on the microorganism surface, which could act as an accumulating skeleton to facilitate the formation of CaCO3. After adding 20 mL of EPS solution during the curing process (Treat group), the maximum unconfined compressive strength (UCS) of the cured body reached 1.922 MPa, which was 12.13% higher than the CK group. The contents of exchangeable Th (IV) and U (VI) in the cured bodies of the Treat group decreased by 3.35% and 4.93%, respectively, compared with the CK group. Therefore, EPS enhances the effect of MICP curing RES and reduces the potential environmental problems that may be caused by radionuclides and heavy metals during the long-term sequestration of RES.

Characteristics of bare rocky land evolution in karst mountain areas of Southwest China based on socio-ecological system perspectives: The case study of Huajiang Canyon

Rock exposure is a prerequisite for the emergence of bare rocky land (BRL), a severe ecological and environmental problem in karst mountain areas (KMA) of Southwest China, severely restricting the region’s sustainable development. An in-depth analysis of the evolution of BRL in KMA of Southwest China based on socio-ecological perspectives is significant for promoting the region’s sustainable development. This paper firstly analyzes the evolution of the social-ecological system and BRL and the transition of human-land relations in KMA of Southwest China, then selects a typical KMA, Huajiang Canyon in Guizhou Province, for a case study and applies ArcGIS to analyze the dynamics of the BRL of Huajiang Canyon in the past 60 years from 1969 to 2020, and reveals the reasons for the evolution of BRL. The results show that: (1) The evolution of BRL in KMA of Southwest China is closely related to the changes in the local socio-ecological environment. (2) The number, spatial distribution, and landscape pattern of BRL in the Huajiang Canyon from 1969 to 2020 underwent significant changes, with the area of BRL transitioning from an expansion phase to an accelerated shrinking phase and with prominent spatial dispersion characteristics. (3) The transition of the BRL of the Huajiang Canyon into forest grassland and economic and fruity forest land, and the transition of land use from production to ecology and eco-economy, have proved the greening of the KMA of Southwest China from a microscopic perspective. (4) This paper shows that the expansion and contraction of BRL areas can reflect the human-land relations in KMA of Southwest China. Finally, the development path proposed in this paper has a certain positive effect on promoting the future sustainable development of the KMA of Southwest China and can also provide a reference for developing other mountainous areas with similar situations.

Harmonizing International Environmental Law and National Sovereignty

International environmental law is an important legal tool to deal with the global environmental crisis. In recent years with the increasingly serious and global environmental problems the speed and depth of environmental problems are also increasing. In this process the relationship between state sovereignty and international environmental law and its conflict become the object of study. "To do a systematic analysis this paper attempts to destroy the conflict between national sovereignty and environmental rights and on the basis of in-depth discussion of the background concept formation and development stage of international environmental law to explore whether the two can be coordinated. In particular the concept of "soft standards" is proposed to analyze its actual status and role in international environmental law and its dialectical relationship between legal significance and legal effect in non-binding international instruments. On the basis of respecting national sovereignty the document said that strengthening the supervision of international mechanisms and improving the national responsibility system can promote the effective coordination of international environmental law and safeguard national sovereignty and realize the mutual benefit and win-win situation of environmental protection and national interests. At the same time it puts forward a more cautious attitude towards the criticism and modification of the soft law of the international environment and emphasizes that the universal basis of the law should be paid attention to in the practical application so as to avoid the marginalization of legal research due to excessive dependence on social analysis methods.This paper aims to provide theoretical support and practical guidance for the further development and practical application of international environmental law.

Land tenure conflicts in forest areas: obstacles to rejuvenation of small-scale oil palm plantations in Indonesia

Purpose This study aims to investigate the problems small-scale oil palm plantations in Indonesia’s forest areas face and the government policies addressing them. Design/methodology/approach Survey and data collection were used to determine the socioeconomic, environmental, legal and governance problems related to the development of smallholder plantations. Information was obtained from the respondents via a rapid rural appraisal approach. Findings The potential land for potential participants in the community oil palm rejuvenation programme is a forest area of 1,628,749.60 ha. Owing to its legal dimensions and unsustainable land management, the rejuvenation regulatory programme has not reached independent farmers. Research limitations/implications The use of plantation space beyond its designation hinders the government’s goal of accelerating the rejuvenation programme. The problems regarding the accumulation of forest area result in low achievement of the annual rejuvenation target in Riau Province (21%–25%). The authors present solutions to resolve land ownership conflicts and implement strategic policies to ensure the sustainable development of such plantations. Originality/value The authors introduce a conflict–resolution model for small-scale smallholder oil palm plantations to resolve the problems of forest area claims unaddressed in the Indonesian Job Creation Law. Land conflict resolution is categorised into five typologies: oil palm plantations with business permits; those without a forestry permit and subject to administrative sanctions; business activities in forest areas without forestry permits; resolving non-conformities in the progress of land or management controlled and used in forest areas prior to their designation by removing land parcels through modifying the forest area boundaries; and the settlement for farmers without cultivation registration certificates but have established plantations and whose land tenure can be proven.

Photochemical Aerobic Upcycling of Polystyrene Plastics via Synergistic Indirect HAT Catalysis.

Plastic pollution constitutes an evergrowing urgent environmental problem, since overaccumulation of plastic waste, arising from the immense increase of the production of disposable plastic products, overcame planet's capacity to properly handle them. Chemical upcycling of polystyrene constitutes a convenient method for the conversion of plastic waste into high-added value chemicals, suggesting an attractive perspective in dealing with the environmental crisis. We demonstrate herein a novel, easy-to-perform organocatalytic photoinduced aerobic protocol, which proceeds via synergistic indirect hydrogen atom transfer (HAT) catalysis under LED 390 nm Kessil lamps as the irradiation source. The developed method employs a BrCH2CN-thioxanthone photocatalytic system and was successfully applied to a variety of everyday-life plastic products, leading to the isolation of benzoic acid after simple base-acid work up in yields varying from 23-49%, while a large-scale experiment was successfully performed, suggesting that the photocatalytic step is susceptible to industrial application.

High-value utilization of boron mud waste: preparation of magnesium oxysulfate cement after primary blank roasting and secondary (NH4)2SO4 roasting

Boron mud, as a typical industrial solid waste, calls for value-added use because of environmental problems caused by stockpiling and waste of considerable magnesium resource. In this work, the primary blank roasted boron mud, as well as the secondary (NH4)2SO4 roasted boron mud were used to prepare magnesium oxysulfate (MOS) cement, then, its characterization and mechanical properties were analyzed and compared systematically. Results showed that the primary blank roasted boron mud can replace 45 % of light burned MgO to prepare MOS cement, whose compressive and flexural strength are 59.0 MPa and 8.0 MPa after curing for 28 d. During the secondary (NH4)2SO4 roasting process of boron mud, MgO and Mg2SiO4 in the primary roasted boron mud transform into MgSO4. The secondary roasted boron mud can replace MgSO4 completely, MOS cement rich in 5Mg(OH)2·MgSO4·7 H2O (517) phase can be obtained with compressive and flexural strength of 70.0 MPa and 9.0 MPa after curing for 28 d. When both of the primary blank roasted and secondary (NH4)2SO4 roasted boron mud are used for preparing MOS cement which compressive and flexural strength are higher than the requirements of the national standard, MgSO4 can be completely derived from the secondary roasted boron mud, the primary blank roasted boron mud can replace up to 35 % of light burned MgO at most, and the total utilization ratio of boron mud is 53.3 wt%. This process not only achieves the high-value utilization of boron mud, but also provides a new thought to prepare MOS cement with high mechanical properties.

Penyisihan Kandungan Perak dalam Limbah Cair Pencucian Film Melalui Proses Biofiltrasi dengan Tanaman Eceng Gondok

Wastewater produced from the film washing process in photo studios generally has very high contents of heavy metals, such as silver (Ag). This situation can cause various health and environmental problems if it is not treated before disposal. Therefore, this research was aimed to reduce the silver content in the wastewater through biological processes. This study was conducted using a biofiltration process using water hyacinth plants. Film washing waste was first acclimatized into concentration of 2.5% and the initial silver content was measured. Afterwards, water hyacinth of 600, 900, 1200, and 1500 g, respectively, was planted into the wastewater. Waste samples were subsequently taken and analyzed every 2 days. The highest removal efficiency of 99.94% was yielded for 1500 g of plant. In this condition, the silver content in wastewater met the environmental quality standards.

DYE 10-N-NONYL ACRIDINE ORANGE AS A FLUORESCENT INDICATOR OF THE ACTION OF THE ANTISEPTIC OCTENIDINE ON THE MEMBRANES OF RHODOBACTER SPHAEROIDES CHROMATOPHORES

Increasing volumes of produced antiseptics and disinfectants, which are widely used in medicine, veterinary medicine, the food industry and everyday life, can create a serious environmental problem after use. Previously, under the infl uence of micromolar concentrations of a number of antiseptics, we identifi ed disturbances in the functioning of photosynthetic membranes and phototransforming pigment-protein complexes isolated from them in various representatives of photosynthetic organisms. In this work, to determine the sensitivity of photosynthetic membranes to the action of the cationic antiseptic octenidine, we used chromatophores of the purple nonsulfur bacteria Rhodobacter sphaeroides, labeled with the fluorescent dye 10-N-nonylacridine orange (NAO). It was shown that the binding of NAO to chromatophores is accompanied by a shift in the dye emission maximum from 525 to 640 nm. The “red” fluorescence of NAO associated with chromatophores turned out to be sensitive to the effect of increasing concentrations of octenidine on photosynthetic membranes. We have found antiseptic concentrations which led to the degradation of chromatophore structures and change in the NAO aggregative state. It can be detected by an increase of “green” fluorescence in the emission spectra of the dye. The properties of NAO as a fluorescent indicator of the functional state of photosynthetic membranes and possible changes that can occur in such systems under the influence of a cationic antiseptic are discussed.

Advanced Development of In situ Characterization Technique for Electrocatalytic Hydrogen Evolution Reaction

AbstractHydrogen evolution reaction (HER) from water splitting using renewable energy provides a promising solution to the global energy crisis and environmental problems. However, the lack of in‐depth understanding of the reaction mechanism and clear identification of the catalytic active site has hindered the further development of low‐cost, high‐performance, and long‐life efficient electrocatalysts. Through in situ characterization techniques, the activity and stability of catalysts can be monitored in real‐time, track the structural evolution of catalytic reaction intermediates, and obtain a deep understanding of catalytic reaction mechanism, so as to feedback and guide the development and utilization of the catalyst. In this review, advanced development of in situ characterization techniques in electrocatalytic HER in recent years is summarized. In situ spectroscopy can be used to track the behavior of reaction intermediates such as adsorption, desorption, and structural evolution at the molecular level to reveal the electrocatalytic HER mechanism. The imaging techniques can be used to observe the evolution of material structure during HER in situ, which provides valuable information for the understanding of visualization of catalytic hydrogen evolution at atomic level. This review contributes to theadvanced development of in situ characterization technique for electrocatalytic HER.

Molecular engineering of PETase for efficient PET biodegradation

The widespread utilization of polyethylene terephthalate (PET) has caused a variety of environmental and health problems. Compared with traditional thermomechanical or chemical PET cycling, the biodegradation of PET may offer a more feasible solution. Though the PETase from Ideonalla sakaiensis (IsPETase) displays interesting PET degrading performance under mild conditions; the relatively low thermal stability of IsPETase limits its practical application. In this study, enzyme-catalysed PET degradation was investigated with the promising IsPETase mutant HotPETase (HP). On this basis, a carbohydrate-binding module from Bacillus anthracis (BaCBM) was fused to the C-terminus of HP to construct the PETase mutant (HLCB) for increased PET degradation. Furthermore, to effectively improve PET accessibility and PET-degrading activity, the truncated outer membrane hybrid protein (FadL) was used to expose PETase and BaCBM on the surface of E. coli (BL21with) to develop regenerable whole-cell biocatalysts (D-HLCB). Results showed that, among the tested small-molecular weight ester compounds (p-nitrophenyl phosphate (pNPP), p-Nitrophenyl acetate (pNPA), 4-Nitrophenyl butyrate (pNPB)), PETase displayed the highest hydrolysing activity against pNPP. HP displayed the highest catalytic activity (1.94 μM(p-NP)/min) at 50 °C and increased longevity at 40 °C. The fused BaCBM could clearly improve the catalytic performance of PETase by increasing the optimal reaction temperature and improving the thermostability. When HLCB was used for PET degradation, the yield of monomeric products (255.7 μM) was ∼25.5 % greater than that obtained after 50 h of HP-catalysed PET degradation. Moreover, the highest yield of monomeric products from the D-HLCB-mediated system reached 1.03 mM. The whole-cell catalyst D-HLCB displayed good reusability and stability and could maintain more than 54.6 % of its initial activity for nine cycles. Finally, molecular docking simulations were utilized to investigate the binding mechanism and the reaction mechanism of HLCB, which may provide theoretical evidence to further increase the PET-degrading activities of PETases through rational design. The proposed strategy and developed variants show potential for achieving complete biodegradation of PET under mild conditions.

Occurrence, distribution characteristics and exposure assessment of perchlorate in the environment in China

Recognizing the extent of perchlorate pollution in the environment is critical to preventing and mitigating potential perchlorate harm to human health. The presence and distribution of perchlorate in Chinese environmental matrixes (water, atmosphere, and soil) were systematically investigated and comprehensively analyzed, and cumulative perchlorate exposure at the regional level was assessed using a combined aggregate exposure pathway method. The results showed that perchlorate is ubiquitous in the environment of China with significant regional differences. The total perchlorate exposure levels in each region of China ranked as South China > Southwest China > East China > North China > Northeast China > Northwest China. Although the average exposure dose of 0.588 (95 %CI: 0.142 −1.914) μg/kg bw/day being lower than the reference dose of 0.70 μg/kg bw/day, it was observed that the intake of perchlorate in some regions exceed this reference dose. Oral ingestion was the primary route of perchlorate exposure (89.97–96.57 % of the total intake), followed by dermal contact (3.21–9.16 %) and respiratory inhalation. Food and drinking water were the main sources of total perchlorate intake, contributing 52.54 % and 31.12 % respectively, with the latter contributing significantly more in southern China than in northern China. In addition, perchlorate exposure from dust sources was also noteworthy, as its contribution was as high as 23.18 % in some regions. These findings will improve understanding of the perchlorate risk and serve as a critical reference for policymakers in crafting improved environmental management and risk mitigation strategies in China and other nations.

Sediment transportation by strong winds over Gobi surfaces: Field observations along the Lanzhou–Xinjiang high‐speed railway

AbstractUnder strong wind action over vast Gobi surfaces, eolian transportation can cause significant environmental problems and infrastructural damage. However, scientific understanding of the underlying mechanisms and dynamics of this process in the Gobi region remains limited. To address this gap, our study focused on investigating eolian transportation over the Gobi surface along the Lanzhou–Xinjiang high‐speed railway (LXHSR) in Northwest China, where strong winds are prevalent. The results indicate that sand transportation heights can reach 9 m in this region, with the saltation layer approximately 3–6 times higher than that of other gravel deserts. The sediment flux density over the Gobi surface exhibited an exponential decrease with increasing elevation; however, the grain‐size vertical profile in wind‐blown sand displayed an increase up to a critical altitude, followed by a decrease with height. The annual eolian transported quantity recorded in this region exceeds that of most deserts worldwide. Notably, fine sand and total suspended particulates (TSP) contributed to approximately 90% of the sediment deposited on railway tracks and drawn in by passing trains. To control transportation of these fine particles, we propose increasing the height of sand‐blocking fences within the current railway wind‐blown sand protection system from 2 to 3 m. Simultaneously, anthropogenic damage to the Gobi surface should be minimized to reduce excessive dust release. This study provides insight into the wind‐blown sand movement mechanism over the Gobi surface under strong winds, and the eolian physics parameters revealed may serve as a theoretical foundation for preventing and managing eolian catastrophes along the Lanzhou–Xinjiang high‐speed railway.

Creative Preservation: A Framework of Creativity in Support of Degrowth

Against the backdrop of the increasing depletion of the planet’s ecological ‘resources’ and endemic environmental problems, the view of creativity as servicing the ideal of infinite economic growth has become problematic. We need, instead, to explore how creativity can contribute to grounding our intentions and actions within an ongoing and mutually shaping engagement and cohabitation between people and things-in-the-world. To explore this issue, we introduce the creative preservation framework. It allows to study practices which have received little attention in the literature to date, despite ensuring continuity, preventing deterioration, and valuing what already exists. Our working definition of creative preservation refers to practices of creation that prevent the decay of existing materials and ideas by updating and adapting them, or re-expressing them in another way through the exploration of their affordances. We examine four practices that reflect non-exhaustive forms of creative preservation practices: upcycling, bricolage, low-tech, and craft. The article opens with an ethos of creative preservation in the context of degrowth. It marks a first step towards creative practices that, rather than viewing us as occupants of the world, make us inhabitants of it, thereby contributing to reimagining new modes of relationality.

The Use of Plant Extracts as Green Corrosion Inhibitors: A Review

The corrosion of metals is very important, both economically and environmentally, and is a serious concern. Since the past decades, traditional (chemical) corrosion inhibitors to prevent corrosion have been and are still being used. Although these inhibitors can be said to be a good choice among other protection techniques because of their good efficiency, the toxicity of many of them causes environmental problems, and, due to the change in the laws on the use of chemicals, many of them are no longer allowed. Hence, during the past years, research on green corrosion inhibitors (GCIs) increased and very favorable results were obtained, and now they are very popular. It can be said that biodegradability and easy preparation are their most important factors. Meanwhile, the use of plants, especially their extracts, has been studied a lot. Plant extracts contain compounds that have anti-corrosion properties. In this review, the use of plants as GCIs is investigated, focusing on recent advances in their use. Also, the phenomenon of corrosion, corrosion protection (including coatings, nanoparticles, and chemical inhibitors), and other GCIs are briefly reviewed.

A Binary Artificial Rabbit Optimization Algorithm for Improved Cognitive Radio Spectrum Allocation

A binary artificial rabbit optimization algorithm is proposed to maximize the cognitive radio (CR) network performance and fairness among users by addressing the issue of low spectrum resource utilization during the CR spectrum allocation process. Building upon the graph coloring spectrum allocation model, Sigmoid is introduced to transform the algorithm solution space. Incorporating the Lévy flight strategy for adaptive step size adjustment enhances the algorithm’s flexibility and convergence accuracy. Moreover, a selective opposition strategy based on Spearman’s coefficient is integrated into the algorithm to improve population diversity and convergence accuracy through reverse learning. Applying the binary artificial rabbit optimization algorithm to the CR spectrum allocation problem in the same CR network environment, we compare network efficiency and inter-user fairness through simulation experiments with the artificial rabbits optimization algorithm seagull optimization algorithm and particle swarm optimization algorithms. The experimental results show that the binary artificial rabbit optimization algorithm has higher convergence performance and global exploration ability, improves the overall network efficiency and user fairness of CR networks, and alleviates the problem of low spectrum resource utilization.

Evaluation of corrosion potential in near-shore piles and analysis through RSM modelling

Corrosion is a significant problem in marine environments that ultimately leads to structural failure and economic losses. The assessment of the conditions of concrete piles is an essential part of corrosion prevention measures in marine environments. This research investigated the corrosion potential of concrete marine piles using a half-cell potentiometer. Following this, the observed potential values are subjected to RSM modeling. Approximately ten piles were chosen in Chennai Fishing Harbor, and the corrosion potential values along the depth of the piles in three different zones, namely, the atmospheric, splash and submerged zones, were measured at three-month intervals. Based on the visual inspection, the piles were damaged, and minor cracks developed on the surfaces of the concrete due to the dynamic impact of wave action, specifically in the splash zone. From the results obtained in the field for the chosen piles in the fishing harbor, the corrosion potential values are in the range of −361.45 mV to −527.57 mV in the atmospheric zone, − 520.67 mV to −784.85 mV in the splash zone and– 401.23 mV to—631.28 mV in the submerged zone. RSM was noted to be the most accurate predictor with the highest R2 and least errors. The RSM model captured the variability of the data according to the R2 threshold (R2 > 0.9855). The splash zones have higher corrosion potentials and are more prone to corrosion than the other zones.

Anticancer Activity of Sargassum fluitans Extracts in Different Cancer Cells.

The arrival of large quantities of Sargassum in the Mexican Caribbean Sea has generated major environmental, health and economic problems. Although Sargassum has been used in the generation of some commercial products, few studies have described its possible applications as a source of compounds with anticancer activity. This study aimed to evaluate the antiproliferative effects of different Sargassum extracts on various cancer cell lines. Furthermore, LC/QTOF-MS was used to identify the compounds related to the antiproliferative effect. First, determination of the seaweed was performed, and dichloromethane, chloroform and methanol extracts were obtained. The extracts were evaluated for their antiproliferative effects by MTT in breast (MDAMB- 231 and MCF-7), prostate (DU-145), lung (A549) and cervical (SiHa) cancer cell lines. Finally, LC/QTOFMS identified the compounds related to the antiproliferative effect. The authentication showed Sargassum fluitans as the predominant species. The extracts of dichloromethane and chloroform showed an antiproliferative effect. Interestingly, the fractionation of the chloroform extract showed two fractions (FC1 and FC2) with antiproliferative activity in MDA-MB-231, SiHa and A549 cancer cell lines. On the other hand, three fractions of dichloromethane extract (FD1, FD4 and FD5) also showed antiproliferative effects in the MDA-MB-231, MCF-7, SiHa and DU-145 cancer cell lines. Furthermore, LC/QTOF-MS revealed the presence of eight major compounds in FC2. Three compounds with evidence of anticancer activity were identified (D-linalool-3-glucoside, (3R,4S,6E,10Z)-3,4,7,11-tetramethyl-6,10-tridecadienal and alpha-tocotrienol). These findings showed that Sargassum fluitans extracts are a possible source of therapeutic agents against cancer and could act as scaffolds for new drug discovery.