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Moisture content of rock/coal can change its mechanical properties and absorption capacities, which can directly affect gas diffusivity, change the stress distribution and hence cause significant impacts on the overall gas or coal extraction process. Observation of the water penetration process and water distribution in the coal matrix will be beneficial for the understanding of the fluid-solid coupling mechanism in hydraulic fracturing, aquifer cracking and coal seam infusion. However, the observation of water penetration process and the determination of water distribution mode were hard to be non-destructively achieved as coal is a non-uniform, inhomogeneous and un-transparent material. µ-CT imaging, which is based on variation of X-ray attenuation related to the density and atomic composition of the scanned objects, enables a four-dimensional (spatial-temporal) visualise of the heterogeneous and anisotropic coal samples. The primary aim of this paper is extending the application of µ-CT imaging to explore the moisture penetration and distribution within coal samples during water infusion process, which has been reported by very little literature. The working principle and procedures of CT imaging was firstly introduced. Then, the determination equation of moisture distribution based on density profile was established. The CT determined moisture content has been compared with weighting method for verification. The paper has demonstrated that µ-CT can be used for non-destructively imaging the moisture distribution within coal samples. [ABSTRACT FROM AUTHOR]

Over the past three decades, groundwater remediation using permeable reactive barriers (PRBs) has proven to be effective. The majority of installed PRBs uses metallic iron (Fe(0)) as a reactive material. However, the success of implemented Fe(0) PRBs is yet to be rationalized as Fe(0) is a generator of iron oxides (contaminant scavengers) and secondary reducing agents (e.g. Fe(II), Fe 3 O 4 , H 2 , green rust), This communication demonstrates that Fe(0) is not an environmental reducing agent. Therefore, more science-based investigations are needed to optimize the operation of Fe(0) PRBs. In particular, Fe(0) PRBs and Fe(0)-based water filters should be regarded as particular cases of "metal corrosion in porous media". A key feature of such systems is that the extent of Fe0 corrosion temporally depends on the residual porosity (capillarity). Thus, the functionality of any Fe0 PRB should be monitored in a way that the time-dependent variation of the kinetic of iron corrosion is discussed. • Metallic iron (Fe0) is currently mainly regarded as an environmental reducing agent. • It is known for a century that, at pH values > 4.5, Fe0 is oxidized only by protons. • The current design and operation of Fe0-based systems is not based on their chemistry. • The time is ripe to base system design on the physico-chemistry of Fe0 corrosion. [ABSTRACT FROM AUTHOR]

AGRICULTURE productivity is severely hampered by salinity stress in many parts of the world, including the Ararat Plain in Armenia. The need for food security is growing worldwide, and new strategies are essential to meet this challenge. In the context of the Ararat Plain, this paper examines the potential utility and promising role of biogenic nanoparticles (NPs) and biochar in reducing salinity stress, boosting crop resilience, and guaranteeing sustainable food production. This paper involves the mechanisms underlying salinity stress, as well as the properties and synthesis of biogenic nanoparticles and biochar, and their applications in increasing plant salinity tolerance. The potential application of biogenic nanoparticles and biochar to mitigate the adverse effects of salinity on crops, soil, and water resources has been recently illustrated by several case studies and research findings. Additionally, we go over the safety issues, environmental implications, and potential applications of biogenic nanoparticles and biochar in sustainable agriculture on the Ararat Plain and elsewhere. This paper advances our knowledge of innovative strategies for addressing salinity stress and improving food security in areas with comparable problems. [ABSTRACT FROM AUTHOR]

This special issue delivers a platform in which researchers expose intersections between algorithm design, software platforms, and hardware architectures to deal with emerging challenges in the scientific field of management of water and water-dependent resources. Since the call for papers was announced in June 2019, this special issue has received 10 manuscripts. After a rigorous review process, 6 papers have been finally accepted for publication. Published papers deal with groundwater quality monitoring, coastal groundwater-dependent irrigation agriculture, desertification risk, water recovery from tailings, future scenarios of water resources, and vulnerability of coastal aquifers. [ABSTRACT FROM AUTHOR]

This study examines the accumulation, distribution, and mobility of Potentially Toxic Elements (PTEs) in the sediments of a low‐lying coastal drainage network (Ravenna, Italy). The aim is to understand the geochemical processes occurring between drainage water and canal bed sediments and assess factors affecting and driving PTE distribution and enrichment in these environments. A geochemical database resulting from the analysis of 203 drainage sediment samples was analyzed using Principal Component Analysis and compared to undisturbed near‐surface sediment samples from the same depth and depositional environment. The results reveal PTEs exceeding national regulation limits. Distance from the sea, electrical conductivity of drainage water, and fertilizer use were identified as the main driving factors. The primary mechanisms for PTE precipitation (As, Co, Mo) and subsequent enrichment in the sediments is attributed to the absorption on Fe‐ and Mn‐oxyhydroxides (HFO and HMO), particularly in high salinity areas near the coast. While Cu, Zn, Pb, Cr, and V also have affinity for HFO and HMO, their adsorption efficiency decreases due to the competition with salt‐derived cations during ongoing salinization processes. Anthropogenic sources, including agriculture, hunting activities, traffic dust, and railways, contribute to the local abundance of other elements (Cr, Ni, Cu, Zn, Pb, and Sn). This paper's significant progress lies in assessing the concurrent interactions of chemical and physical processes that drive PTE distribution and accumulation in reclaimed low‐lying coastal plains. The findings are significant for assessing PTE accumulation risks and sediment toxicity in coastal areas affected by water salinization, drainage, and subsidence, providing valuable information to water management institutions globally. Plain Language Summary: This study investigates the presence of harmful substances called Potentially Toxic Elements (PTEs) in the sediment of the drainage canals in Ravenna's coastal area (Northern Italy). Researchers want to understand how these substances accumulate and spread in the sediment and what factors influence their distribution. They collected sediment samples from the bottom of the drainage canals and compared them to natural sediment samples. The results show that the PTE levels exceed the national and international limits. The distance from the sea, the water salinity, and the fertilizers are found to be the main factors affecting the distribution of PTEs. The researchers also discover that some PTEs (Arsenic, Cobalt, and Molybdenum) are absorbed by certain minerals in the sediment, especially in areas with high salinity close to the coast. However, other harmful elements, like copper, zinc, lead, chromium, and vanadium are not as strongly absorbed due to competition with salt‐related substances. The abundance of other elements like chromium, nickel, copper, zinc, lead, and tin come from human activities like agriculture, hunting, traffic, and railways. These findings are important for understanding the risks associated with these substances in the sediment, particularly in low‐lying coastal areas that have been reclaimed for human use. Key Points: First study on Potentially Toxic Elements (PTEs) enrichment in drainage canal sediments of reclaimed low‐lying coastal areaKey roles of (i) Fe‐ and Mn‐oxyhydroxides in PTE enrichments and (ii) salt‐derived cations in adsorption efficiencyDistance from the sea, salinity of drainage water, and use of fertilizers are the main factors affecting the distribution and enrichment of PTEs [ABSTRACT FROM AUTHOR]

The interaction between climate warming and alien fish invasions could have severe consequences in inland waters, which represent isolated environments with high biodiversity richness. Due to the current climatic trend, increasing water temperatures and salinization, shorter ice cover period, and altered flow regimes are predicted for these environments. The aim of this review is to offer a comprehensive analysis at a global scale of the recent studies available in the literature, focused on the responses of invasive freshwater fish to the effects of climate change in both lotic and lentic environments. To achieve this purpose, we selected 34 relevant papers, using the Scopus and Google Scholar database. New alien species establishment, distribution range expansion of species already introduced, and exacerbating impacts on freshwater ecosystems and the native fish communities they host were included in the topics covered by the analyzed papers. Despite the uncertainties related to the unpredictability with which the effects of global warming will occur, the findings of the selected studies served as a support to evaluate conservation and management implications, with particular reference to possible mitigation strategies. [ABSTRACT FROM AUTHOR]

This paper takes the freezing project of the North Arch Tunnel of the Hong Kong–Zhuhai–Macao Bridge as an example. Based on Darcy's law and the theory of heat transfer in porous media, using the coupled module of the temperature field and seepage field in the COMSOL Multiphysics software, numerical simulations of the freezing reinforcement of the new pipe curtain freezing method are conducted to study the influence of different factors on this method under seepage conditions. The research shows that an increase in the groundwater flow velocity will affect the development of frozen soil curtains, prolonging the formation time of frozen soil curtains. A rise in the initial ground temperature will increase the time required for the formation of frozen soil curtains during the freezing process, resulting in a slight increase in the temperature of the final frozen soil curtains. With an increase in the salinity of the groundwater, the temperature at the temperature measurement point upstream of the freezing pipe increases, while the temperature at the temperature measurement point downstream of the freezing pipe decreases. The average temperature of the frozen soil curtain also increases with an increase in the salinity of the groundwater. This study is expected to provide a valuable reference for similar projects in the future. [ABSTRACT FROM AUTHOR]

In the CCUS project, CO2 utilization had achieved remarkable results in oil displacement. But, at present, one of the main reasons that seriously affected the large-scale application of CCUS projects was that the corrosion behavior of underground environment on pipe string or wellbore was not fully evaluated. It was revealed that the wellbore corrosion behavior in the harsh environment in the process of CO2 flooding was the key to ensure the safe production of oil fields. Therefore, this paper took the corrosion environment with temperature of 81.7°C, pressure of 52.3 MPa and high salinity in the well depth of 4517 m as the research object, to study the corrosion behavior of oil casing N80 steel through corrosion rate, corrosion morphology and electrochemical experiments. The results showed that the corrosion rate increased with the increase of experimental time, behaved by the charge transfer resistance decreased. However, when the experiment increased from 800 h to 1000 h, the pitting corrosion rate increased from 1.47 mm/a to 1.782 mm/a, which was consistent with the ratio of anode/cathode Tafel constants and corrosion density. This was mainly because the relatively dense FeCO3 corrosion product layer generated on the N80 steel surface gradually brook down due to synergistic effect of amorphous CrO3, Fe2+/Ca2+ complex salt and Cl– during the experiment, which promoted the initiation and development of the corrosion pits. Compared with the bare N80 steel, the incomplete corrosion product layer aggravated the rapid development of pitting corrosion. [ABSTRACT FROM AUTHOR]

In this paper, the aluminum gel with polymeric aluminum chloride (PAC) as the gelling agent and carbamide as a catalyst were investigated. The gelling regularities were studied, and its gelling performance was evaluated under high temperature and high salinity. The results showed that the basicity, mass fraction of PAC and carbamide, temperature, and salinity significantly influenced the formation of the gel. The gel exhibited exceptional thermal stability and gel strength under high temperature and salinity conditions. The results indicated that when the aluminum gel was prepared with 8 wt% PAC and 1 wt% carbamide and dissolved in brine with a salinity of 110,000 mg/L, the dehydration rate was less than 1 wt% after being aged for 180 days at 130 °C. Furthermore, the gel strength, elasticity, and yield stress increased with the rise in salinity. The experimental results showed that the aluminum gel is highly significant in plugging reservoirs with high temperature, high salinity, and low permeability. [ABSTRACT FROM AUTHOR]

The dissolution of hydrolyzed polyacrylamide, commonly used in gel treatments for enhanced oil recovery, takes between 2-3 to over 24 h at 20-25 °C. The duration is influenced by factors such as polymer molecular weight and brine salinity. In injection/production wells, gel treatments often involve injecting 50-150 m3 of polymer solution within 1-2 days, resulting in the injection of partially dissolved polymer. This raises concerns about the stability and strength of gels containing partially dissolved polymer particles. This study demonstrates that when undissolved polymer particles are kept suspended during the gelation process, there is no significant visual distinction between gels obtained from 30 min or 12 h of polymer mixing. Additionally, viscometer measurements reveal that gels formed with shorter polymer mixing times exhibit higher resistance to shearing. This observation supports the concept that undissolved polymer particles act as a composite material, improving the gel strength. This paper does not advocate for the use of partially dissolved polymer gelants. Undissolved polymer particles cannot effectively penetrate porous media. Gelants containing such particles are primarily suited for addressing fracture conformance issues. Therefore, future research will focus on examining the impact of polymer mixing time on gel syneresis and resistance to washout from fractures. [ABSTRACT FROM AUTHOR]

The salinity of the salt lake is an important factor to evaluate whether it contains some mineral resources or not, the fault buried in the salt lake could control the abundance of the salinity. Therefore, it is of great geological importance to identify the fault buried in the salt lake. Taking the Gasikule Salt Lake in China for example, the paper established a new method to identify the fault buried in the salt lake based on the multi‐source remote sensing data including Landsat TM, SPOT‐5 and ASTER data. It includes the acquisition and selection of the multi‐source remote sensing data, data preprocessing, lake waterfront extraction, spectrum extraction of brine with different salinity, salinity index construction, salinity separation, analysis of the abnormal salinity and identification of the fault buried in salt lake, temperature inversion of brine and the fault verification. As a result, the study identified an important fault buried in the east of the Gasikule Salt Lake that controls the highest salinity abnormal. Because the level of the salinity is positively correlated to the mineral abundance, the result provides the important reference to identify the water body rich in mineral resources in the salt lake. [ABSTRACT FROM AUTHOR]

Both natural and anthropogenic processes can lead to the increasing salinity of surface waters. The knowledge about the ecological consequences of salinization on the biota is limited especially in case of microbiota, like diatoms. We collected the existing knowledge about the relationship between salinity and diatoms in fresh and saline waters. Based on the available papers, conductivity and ion composition are the most important variables shaping diatom communities. Secondary salinization can mask regional differences in diatom assemblages. Trait-based analyses highlight the competitive advantages of motile guild and the extreme trait categories in these environments. The increasing conductivity along a wide conductivity scale decreases the alpha-diversity. Salinization induces the spread and invasion of marine and brackish species into inland freshwaters as well as that of freshwater species tolerating elevated conductivity and/or need specific ions. Concerning food webs, salinity can directly change diatom communities and the subsequent upper trophic levels but most likely this effect manifests as a top-down regulation. Applicable diatom indices are available to assess the level of salinization. Furthermore, diatom-inferred salinity reconstructions are widely applied to assess the past changes of salinity. However, future models predicting ecological consequences of salinization are scarce and sometimes contradictory. [ABSTRACT FROM AUTHOR]

In the process of natural gas production using foam to lift liquid, there exists obvious difference in the requirements of foam stability between wellbores and gathering & transportation systems. To ensure the effect foam dewatering of gas wells and highly efficient defoaming and gas-water separation on surface, it is meaningful to investigate the influencing factors of foam stability comprehensively. In this paper, a tight gas block in China which adopted foam for liquid lifting was taken as an example. It was researched that the key influencing factors and changing rules of foam stability through static and dynamic experiments on foam stability, chemical defoaming experimets and field tests. The results showed that the concentration of foaming agent used in the field, namely UT-11C, had the most significant effect on the foam stability followed by the salinity, temperature and PH value. Foam stability was also can be improved with higher pressure. Results of chemical defoaming experiments showed that even under the optimal defoaming concentration, mamely 1%, it also took about 20 minutes to completely eliminate the foam. Combined with the laboratory results and the statistical analysis of the water production in field, the optimal injection amount of foaming agent was calculated, which makes the dosage reducing by 40%. And the effective was validated by field test. This work not only ensures the high production of gas wells, but also takes the economy into account, having a strong guidance for the production of natural gas fields. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to evaluate the protection performance of zinc as sacrificial anode for ABS A steel in the presence of H2S under different temperatures, pH and salinities. Design/methodology/approach: In this paper, weight loss measurements and electrochemical measurements are used to evaluate the corrosion degree of zinc and ABS A steel. Findings: Under the conditions involved in this work, it is shown that zinc is a nice sacrificial anode with the reason of its stable potential and excellent anode current efficiency according to the relevant standard. And it is also found that the hydrogen evolution does not occur on ABS A steel specimens. The potential difference between cathode and anode is suitable; thus, it can be concluded that each steel is well protected. Originality/value: To the best of the authors' knowledge, no other study has analyzed the protection mechanism and effect of zinc as sacrificial anode in H2S-containing environments under high temperature at present. [ABSTRACT FROM AUTHOR]

The accurate temperature and thermal front prediction in aquifer thermal energy storage systems during reinjection are crucial for optimal management and sustainable utilization. In this paper, a novel two-way fully coupled thermo–hydro model was developed to investigate the dynamic thermal performance and fronts for multiple aquifer thermal energy storage systems. The model was validated using a typical model, and the evolution characteristics of wellbore temperature before and after the breakthrough of the hydraulic front and thermal front were deeply studied. Sensitivity analysis was conducted to delineate the influence of various reservoir and reinjection factors on the thermal extraction temperature (TET). The results revealed that thermal conductivity significantly impacts the thermal extraction rate among the various reservoir factors. In contrast, volumetric heat capacity has the weakest influence and negatively correlates with the TET. Concerning the reinjection factors, the effect of the reinjection volume rate on the TET was significantly more significant than the reinjection temperature. Furthermore, the correlation between the TET and different properties was observed to be seriously affected by the exploitation period. The coupled model presented in this study offers insight into designing the exploitation scheme in deep reservoirs and geothermal resources. [ABSTRACT FROM AUTHOR]

Determining the minimum supercooling temperature (Tsc) of unsaturated saline soils is the key scientific problem in cold‐region agricultural and engineering, and theoretical models with good predictability are urgently needed. This study establishes a framework for pore solution freezing nucleation in unsaturated saline soils, the chemical potential energy balance equation was established by determining phase transition driving force and potential energy barrier for the formation of stable crystal embryos. Finally, the physical model was constructed. By citing 46 sets of data from different researchers, the validity of the prediction results of this paper's model under different soil types and cooling rates is demonstrated, and the microscopic mechanism of supercooling occurring in the pore solution of positive permafrost is elucidated. The analysis found that electrolyte action restricts the free diffusion of molecules and promotes nucleation to occur, so that a maximum value of Tsc exists during the growth of salinity (in NaCl saline soils occurs at a solution concentration of 0.26 mol/L). Too fast cooling rate will lead to a lag in crystallization time and an increase in supercooling. The combined water content determines the Tsc when rc < 1 μm (pore size), and the effect of changes in water content and cooling rate on supercooling is more significant in small pores; the electrolyte concentration determines the Tsc when rc > 1 μm, Tsc‐max from concentration changes will be more significant in large pores. This study can provide theoretical reserves for controlling the freezing process of soils, studying the mechanism of freezing‐thawing hysteresis, and improving the related numerical calculation models. Plain Language Summary: Permafrost and seasonal permafrost cover more than 50% of land area in the world. The engineering problems caused by freezing‐thawing cycles seriously affect engineering safety and people's well‐being in many countries. Therefore, an in‐depth study of the soil freezing‐thawing cycle is necessary. The water in the soil pore space remains sometimes in liquid state when it is below the freezing temperature. This phenomenon is usually referred to as supercooling. There is still a lack of quantitative studies on the minimum temperature that can be reached by this phenomenon. In this paper, a model that can reasonably predict the minimum subcooling temperature of soil is developed based on thermodynamic methods. The model is verified to be of good accuracy by means of measured data from different researchers. Subsequently, the supercooling characteristics of the soil are discussed based on the model and the microscopic mechanism of the gradual development of freezing in the supercooling state is described. This study will help to recognize and control the soil freezing process in engineering and agricultural construction, and serve to protect engineering structures. Key Points: A physical model is proposed to quantify the supercooling degree of unsaturated saline soilsA maximum value of soil minimum supercooling temperature will occur with increasing salt concentrationToo fast cooling rate will lead to a lag in crystallization time and an increase in supercooling [ABSTRACT FROM AUTHOR]

This study aims to illustrate and present various techniques for evaluating the performance of check-dams and proposes some suitable approaches for impact assessment of dams built in the Balochistan province of Pakistan. These dams were built during the last decade to overcome the challenges of water scarcity and depleting aquifers due to excessive Groundwater (GW) extraction. It was expected that these dams would recharge the GW resources and save the aquifer system from collapsing. Check-dams have traditionally been the permanent source of water within the province. A check-dam is used to delay the floodwater runoff to make it available for domestic and agriculture purposes or to recharge GW. The water along these dams permeates into the ground to keep the aquifer genuinely stable throughout the year. The data were collected based on studies of published research papers and reports of international organizations containing key characteristics of performance evaluation techniques. This review will help to evaluate procedures, policy, and governance interventions in Balochistan by comparing them with the adopted practices in other regions of the world and its impact on the well-being of the society. In this paper, the performance evaluation of check-dams for specific cases is presented. The knowledge acquired will be utilized to highlight state-of-the-art practices and to identify the need for further research in this field. [ABSTRACT FROM AUTHOR]

In last decade, Prosperity in contemporary Saudi Arabia and the consequent stresses on renewable freshwater resources resulted in the bottled drinking water market. Over the period, sustainable water resources planning (SWRP) has become an essential requirement for the development of places where these resources are highly constrained. To meet this market growth in Saudi Arabia is augmented by increasing demand for bottled water. This drastic increase, leads some countries to develop an alternative sources including desalinated water and treated wastewater for landscaping irrigation, industrial reuse, street cleaning, and aquifer recharge. There are claims on health concerns the possibility of chemicals migration from polyethylene terephthalate (PET) bottles into drinking water. In this paper, inductively coupled plasma -optical emission spectrometry (ICP-OES) was utilized and applied to determine the antimony (Sb) release from PET bottles into mineral water of 8 local brands at different temperature degrees within 8 months storage time. [ABSTRACT FROM AUTHOR]

In such areas, the significant increases in sea level and atmospheric temperatures due to climate change could exacerbate water resources salinization. All over the Earth, more and more studies have shown the effects of climate changes generated by anthropic release of greenhouse gasses on the hydrological cycle [[1]]. The already increased demand of freshwater triggered by climate change and the consequent land use changes, has intensified the research on water resources salinization and the feasible techniques aimed at mitigating such effects, such as for example the wastewater reuse via managed aquifer recharge systems [[10]]. The third paper published in this Special Issue provided a background to the salinity issue in the Murray-Darling Basin (Australia), then reviewed the salinity management strategies, the various actions that have been implemented through these strategies to control salinity, and the role of the recent Basin Plan in salinity management [[15]]. [Extracted from the article]

Using the data of private listed companies in east China coastal cities from 2009 to 2014, this paper empirically tested the impact of social capital on investment of private enterprises in east coastal areas within the context of economic transformation. The results show that political connections, financial relations, and commercial association relations have significant impacts on private enterprise investment in east China coastal cities. However, with the increasingly fair competition market environment and the anti-corruption activities, it finds that the influence of hierarchical social capital (such as political relations) on private enterprise investment in east China coastal cities is gradually decreasing, while market based social capital (such as business association relations) still maintains a significant positive impact on private enterprise investment in east China coastal cities. [ABSTRACT FROM AUTHOR]

This paper chooses the most representative second-tier coastal cities in the critical period of China's economic transformation as the research object. This paper innovatively constructs the evaluation system of manufacturing transformation and upgrading environmental measurement from the specific content contained in ''Made in China 2025'' which leads the transformation and upgrading of China's manufacturing industry. Using the combination of factor analysis and cluster analysis, combined with the entropy weight method of objective weighting, the measurement and difference of coastal environment in manufacturing transformation and upgrading are studied. The results show that the development environment of the transformation and upgrading of the manufacturing industries in different cities is quite different. The most prominent feature of the empirical analysis is that Hangzhou is a typical city, showing that the supporting factors of innovation capability play an important role in the transformation and upgrading of manufacturing. [ABSTRACT FROM AUTHOR]

Consistency of observed oceanographic salinity data is discussed with respect to contemporary metrological concepts. The claimed small uncertainty of salinity measurement results traceable to the conductivity ratio of a certified IAPSO Standard Seawater reference is not metrologically justified if results are compared on climatic time scales. This applies in particular to Practical Salinity SP, Reference Salinity SR, and the latest estimates of Absolute Salinity using the TEOS-10 formalism. In climate time scales an additional contribution to the uncertainty that is related to unknown property changes of the reference material must be accounted for. Moreover, when any of these measured or calculated quantity values is used to estimate Absolute Salinity of a seawater sample under investigation, another uncertainty contribution is required to quantify the accuracy of the equations relating the actually measured quantity to the Absolute Salinity. Without accounting for these additional uncertainties, such results cannot be used to estimate Absolute Salinity with respect to the International System of Units (SI), i.e. to the unit chosen for the mass fraction of dissolved material in the sample, which is "g/kg". From a metrological point of view, such deficiencies in the calculations involving other quantities will produce SI-incompatible results. We outline how these problems can be overcome by linking salinity to primary SI measurement standards. [ABSTRACT FROM AUTHOR]

Fungi produce surface-active proteins, among which hydrophobins are the most characterized and attractive also for their ability to form functional amyloids. Our most recent findings show that these abilities are shared with other classes of fungal proteins. Indeed, in this paper, we compared the characteristics of a class I hydrophobin (Vmh2 from Pleurotus ostreatus) and an unknown protein (named PAC3), extracted from the marine fungal strain Acremonium sclerotigenum, which does not belong to the same protein family based on its sequence features. They both proved to be good biosurfactants, stabilizing emulsions in several conditions (concentration, pH, and salinity) and decreasing surface tension to a comparable value to that of some synthetic surfactants. After that, we observed for both Vmh2 and PAC3 the formation of giant fibers without the need for harsh conditions or long incubation time, a remarkable ability herein reported for the first time. [ABSTRACT FROM AUTHOR]

A heat storage tank (HST), described in this paper, may be applied to numerous systems used for thermal energy generation and storage. Working principle and heat-flow processes of the HST remain the same and are independent of the systems in which the HST is being used. This paper presents a thermal-flow analysis of a heat storage tank (HST) operating in an air compressor heat pump (ACHP) and a dry cooler (DC) combined cycle. The HST is operated under transient conditions for four different ACHP steady states. The HST was analysed using lumped capacitance method. The heating power of a single coil varied from 2.2 to 3.2 kW. 50% increase in mass flow rate of heating water in the coils increased the HST water mean temperature by 5.6 °C. A differential equation for the HST water temperature variation was solved analytically and it was presented with the use of dimensionless numbers. The presented solution is of a general form. An important parameter such as number of the coils may be varied easily. Additionally, a Mathcad computational program was proposed for the estimation of HST-ACHP-DC system thermodynamic and thermal-flow parameters. System dynamics was studied using MATLAB/Simulink. An optimal operating parameters of the HST were found and are presented in the paper. The aforementioned parameters are as follows: mass flow rates of heating and cooling media in all three coils, mass flow rate of freshwater supplying the HST, number of loops in coils and resulting heat transfer area, diameter of the loops of the coils, diameter of the coils, time after which water in the HST reaches a steady value, time period within which the HST may fulfil demand for central heating and domestic hot water (DHW) preparation without being charged simultaneously. The presented analytical model was validated based on the available data in the field literature and a high compliance was reached. For this purpose theoretical model results were compared to results of HST computational fluid dynamics (CFD) simulations. The temperature calculated using the presented model differed from the one obtained by the CFD analysis by 2.96 K. [ABSTRACT FROM AUTHOR]

The paper is devoted to comparative analysis of detailed gas-geochemical studies carried out in the Alekseev Bay (Peter the Great Gulf, Japan Sea) in 1989 and 2022. The distribution of methane and carbon dioxide in water is given in details. CTD measurements were made to determine water temperature and salinity. The main regularities in the distribution of gas geochemical fields in the Alekseev Bay (Peter the Great Gulf) are shown basing on the available geological information, taking into account the materials of the predecessors. The results obtained are in demand both in theoretical studies of the gas geochemical fields distribution on the Earth's surface in connection with the seismotectonic and geological features of the region, and in the practice of developing methods and technologies for measuring the balance flows of the main greenhouse gases, emission and absorption. The results are also relevant for the implementation of research programs within the "climate agenda." [ABSTRACT FROM AUTHOR]

Polymer gels suffer from a serious syneresis issue when exposed to high-temperature and high-salinity (HTHS) conditions, which limits their use as water-treatment agents in this type of reservoir. In this paper, the effects of the polymer type/concentration, deoxidizers, and stabilizers on the long-term stability of polymer gels were systematically studied; thus, the methods to develop stable polymer gels for two typical levels of salinity were optimized. The results show the following: (1) For a medium-salinity condition (TDS: 33,645.0 mg/L) at 125 °C, conventional HPAM gels completely dehydrate within only 1 day, and the addition of a deoxidizer hardly improved their stability. Some special polymers, e.g., AP-P5, MKY, and CPAM, are able to form stable gels if a high concentration of 0.8% is used; the syneresis rate of these gels is about 10% after 30 days. However, the addition of the complexant sodium oxalate significantly improves the stability of gels formed by all five of these different polymers, which behave with a 0% syneresis rate after 30 days pass. Complexants are the most economical and feasible agents to develop stable gels in medium-salinity water. (2) Gels enhanced using the methods above all become unstable in a more challenging ultra-high-saline condition (TDS: 225,068.0 mg/L). In this case, special calcium- and magnesium-resistant polymers are required to prepare stable gels, which show 0% syneresis rates after 30 days, have relatively low strengths, but do produce a good plugging effect in high-permeability cores. [ABSTRACT FROM AUTHOR]

Worldwide abiotic stress factors such as excessive temperature, precipitation, drought, salinity, soil pH, greenhouse gases, ultraviolet (UVB) radiation, and air pollution pose a persistent threat to both diseases and plants affecting hostpathogen relationship depending on geographical and temporal distribution of inoculum amount and cultivars susceptibility. Leaf rust of rye, which is caused by Puccinia recondita f. sp. secalis (Roberge ex. Desmaz) has become one of the most important limiting factors for rye production in Central and Eastern Europe. During 2020-2021 growing season, a plant-pathogen interaction profile was observed on four rye genotypes in a randomized complete block design with three replications in dry area from Research and Development Station for Plant Culture on Sands Dăbuleni in south of Romania. Adult plant partial resistance was assessed through host response and epidemiological parameters as final rust severity (FRS), area under the disease progress curve (AUDPC), relative area under the disease progress curve (rAUDPC), coefficient of infection (CI) and infection rate (IR). The response of rye genotypes to leaf rust included different variation in resistance reaction ranging from moderately resistant to very susceptible. A negative and highly significant correlation of AUDPC with grain yield (r = -0.9222***) was found during 2020-2021 cropping season. [ABSTRACT FROM AUTHOR]

Groundwater salinization caused by natural and anthropogenic processes can increase the salinity above the concentrations recommended for specific uses or environments. Approximately 16% of the total land area on Earth suffers from groundwater salinization, potentially creating significant social, economic, and environmental problems. Global bibliographical research focusing on studies related to the utilization and management of salinization-threatened groundwater was conducted. A database of 520 papers from 85 countries was compiled and discussed. The main salinization sources were identified, and seawater intrusion is the primary studied phenomenon. This paper classifies different state-of-the-art approaches for protecting groundwater resources from salinization. Practical scientific solutions, from technical and engineering solutions to rules or regulatory instruments, are discussed from a global perspective. As salinization risk becomes a relevant problem, more complex initiatives should be applied to meet water demands while minimizing disadvantages. From the lowest to the highest complexity, three approaches were defined: the engineering approach, the discharge management approach, and the water and land management approach. The discussion presents directions for future research opportunities. [ABSTRACT FROM AUTHOR]

Inorganic chlorine is susceptible to water and soil salinization due to its non-degradability and high mobility. To clarify the environmental risks associated with the active inorganic chlorine in municipal solid waste (MSW), the specific characteristics and contributions of inorganic chlorine in different MSW categories were investigated in this study. MSW samples were collected from eight representative waste classification residential areas in Hangzhou, China. It was found that the inorganic chlorine content in different MSW categories varied significantly (0–113 mg/g). Perishable waste, paper, and plastic were found to be the main sources of inorganic chlorine in MSW. A four-category classification system was used to quantify the contribution of inorganic chlorine from each waste category. It was found that the misclassification of inorganic chlorine contributions from perishable waste and other waste accounted for 51.96% and 48.04%, respectively. However, when correctly classified into the four-category system, their contributions were reduced to 67.14% and 30.65%, respectively. Therefore, MSW classification showed a significant reduction in the overall contribution of inorganic chlorine. The misclassification reduces the contribution of inorganic chlorine to 48.04%, while correct classification increases the reduction to 69.35%. [ABSTRACT FROM AUTHOR]

Bare, non-pretreated platinum wires and screen-printed platinum electrodes were used as both working and counter electrodes in the measurement of dissolved oxygen using a chronoamperometric method. The oxygen reduction current response in the diffusion state was used for a linear determination of air saturation. We evaluated the two different materials in general for their sensing performance such as conditioning time, accuracy, resolution and stability over 13 h of continuous mid-term measurement. A good performance was found for the wire electrodes in terms of accuracy with a current slope of 1.0–1.6 µA (% as)-1 and a resolution of 10–15 nA (Lowest Level of Detection = 0.1% as), but with an unstable current response result over the course of the measurement. The screen-printed electrodes have a resolution of 10–18 nA (Lowest Level of Detection = 0.6–0.8% as) and an accuracy of 620–660 nA (% as)-1 but they showed promising reproducibility and stability. Both materials require several hours of conditioning in the chronoamperometric method before a stable current response is achieved. For biotechnological applications, the platinum screen printed electrodes were evaluated in typical parameter settings (pH 4.0 and 7.4, salinity 0.1 to 10x phosphate buffered saline and temperature 12 to 42 °C) and showed correlations between the response time and stability and the temperature. No correlations were found between salinity, pH and the current response. In this paper, we present inexpensive electrode materials and a simple to implement chronoamperometric method for reliable direct measurement of dissolved oxygen in aqueous media. [ABSTRACT FROM AUTHOR]

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The exploration of unconventional hydrocarbons may be very effective in promoting economic development and confronting energy crisis around the world. However, the environmental risks associated with this practice might be an impediment if not adequately dimensioned. In this context, naturally occurring radioactive materials and ionizing radiation are sensitive aspects in the unconventional gas industry that may compromise the environmental sustainability of gas production and they should be properly monitored. This paper provides a radioecological assessment of the São Francisco Basin (Brazil) as part of an environmental baseline evaluation regarding the Brazilian potential for exploring its unconventional gas reserves. Eleven and thirteen samples of surface waters and groundwater were analyzed for gross alpha and beta using a gas flow proportional counter. A radiological background range was proposed using the ± 2 Median Absolute Deviation method. Using geoprocessing tools, the annual equivalent doses and lifetime cancer risk indexes were spatialized. Gross alpha and beta background thresholds in surface water ranged from 0.04–0.40 Bq L−1 to 0.17–0.46 Bq L−, respectively. Groundwater radiological background varies from 0.006–0.81 Bq L−1 to 0.06–0.72 Bq L−1 for gross alpha and beta, respectively. All environmental indexes are relatively higher in the south of the basin, probably a direct response to the local volcanic formations. Traçadal fault and local gas seepages might also influence the gross alpha and beta distribution. All samples have radiological indexes below the environmental thresholds, and should remain at acceptable levels with the development of the unconventional gas industry in Brazil. [ABSTRACT FROM AUTHOR]

High‐temperature geothermal areas are often characterized by widespread surficial manifestations, whose location is strictly controlled by sets of faults of regional relevance. The geochemical and isotopic signature of the discharged fluids can reveal key information on the geothermal fluids pathway, shedding light on the sources and fluid‐rock interaction within the geothermal reservoirs. In this paper, a geochemical and structural data set from the Larderello geothermal area and surroundings is presented and discussed. We constrain the role of transfer and normal faults in controlling the geothermal circulation enhanced by a cooling magmatic intrusion underneath the Lago area (SW of Larderello). The structural control on the fluids circulation is highlighted by both the location of the CO2 emissions along the fault segments, where permeability is enhanced, and their degassing rates, which increase moving away from the core of the Larderello geothermal system. The main results unravel the presence of deep regional pathways along which endogenous fluids circulate before being discharged in the investigated areas. The peripheral zone emissions are affected by interaction with shallow aquifers and condensation processes whereas the CO2 emitted from the central areas, located near the core of the geothermal system, was accompanied by high amounts of steam, and suffers intense shallow fractionation processes. The latter areas emit medium‐to‐low normalized‐CO2‐degassing rates (<270 t d−1 km−2) when compared to the extremely high values occurring in the peripheral sectors (up to 1,300 t d−1 km−2) of the Larderello geothermal systems, possibly suggesting an incipient propagation of such a system, likely wider than previously thought. Plain Language Summary: High‐temperature geothermal areas are specific zones on Earth where the geothermal gradient is greater than the average global value (∼30°C km−1). This is due to the existence of cooling magma source(s) at depth, providing heat that is transmitted to fluid reservoir(s) located at intermediate levels continuously and naturally fed by recharging fluids, and sealing rock(s) at shallower levels that maintain reservoir temperature and pressure. These geothermal areas commonly show steam‐dominated manifestations at the surface, accompanied by relevant degassing of carbon dioxide likely originated from different feeding systems (biogenic, thermometamorphic, and mantellic). Defining sources, processes, and transport mechanisms governing the CO2 emissions from soils is challenging but pivotal to understand the geothermal fluid origin, dynamics, and relation with the geological structures. To unravel these processes, we combined geochemical and structural measurements performed at the Larderello‐Travale‐Radicondoli (LTR) geothermal field (Italy). Distinct geothermal sectors were investigated according to their geochemical characteristics, CO2 degassing rates, and geological‐structural features, to understand how CO2 is transported and modified during its journey from the deep geothermal reservoir(s) to the surface, exploiting the permeability of fault zones and/or fractured rocks. Results suggest that the LTR geothermal system might be wider than previously thought, indicating a higher geothermal potential. Key Points: Extensive CO2 soil degassing measurements and carbon isotopic composition in the Larderello geothermal system were carried outHydrothermalized hot‐ and cold‐degassing areas are controlled by structural settingRegional transfer zones enhance the circulation of deep‐seated geothermal fluids [ABSTRACT FROM AUTHOR]

Brackish water is usually consumed by almost all population in southern Algeria as fresh water despite its high salinity. This region has a significant potential of solar energy and enormous reserves of brackish groundwater which can be exploited by solar desalination systems to supply small communities by potable water. In the current paper, we propose a new contribution to improve the performance of the conventional solar distiller using abundant local dune sand as heat storage medium and photo-catalytic additive within the absorber plate. Experimental results carried out at Ouargla's University show that — The yield is proportional to some extent certain value with the sand surface density. — For a particle's diameter ≤0.08 mm, the optimal value of the sand surface density is (sand 2.815 kg/m2 of absorber area); this leads to a daytime improvement of 61.46% on the yield compared to the baseline case. — Moreover, adding (charcoal 0.563 kg/m2 of absorber area) to the brackish water within each unit increases the output by a mean of 13.82%. After sunset, the distillation process continues for significant time. — Finally, after an economical and physical analysis, the distillate is produced with low cost and high quality. [ABSTRACT FROM AUTHOR]

Double-diffusive convection, in which a fluid is acted upon by two fields (such as temperature and salinity) that affect the density, has been widely studied in areas as diverse as the oceans and stellar atmospheres. Assuming classical Fickian diffusion for both heat and salt, the evolution of temperature and salinity are governed by parabolic advection–diffusion equations. In reality, there are small extra terms in these equations that render the equations hyperbolic (the Maxwell–Cattaneo effect). Although these corrections are nominally small, they represent a singular perturbation and hence can lead to significant effects when the underlying differences of salinity and temperature are large. In this paper, we investigate the linear stability of a double-diffusive fluid layer and show that amending Fick's law for the temperature, or the salinity, alone can lead to new modes of oscillation and to very large changes in the preferred wavelength of oscillatory convection at onset. In particular, the salt finger regime of classical double diffusion is here replaced by Maxwell–Cattaneo oscillations when the salt concentration is very high. The more complicated case when both laws are amended is left to a future paper, now in preparation. [ABSTRACT FROM AUTHOR]

Microplastics are a widespread contaminant found not only in various natural habitats but also in drinking waters. With spectroscopic methods, the polymer type, number, size, and size distribution as well as the shape of microplastic particles in waters can be determined, which is of great relevance to toxicological studies. Methods used in studies so far show a huge diversity regarding experimental setups and often a lack of certain quality assurance aspects. To overcome these problems, this critical review and consensus paper of 12 European analytical laboratories and institutions, dealing with microplastic particle identification and quantification with spectroscopic methods, gives guidance toward harmonized microplastic particle analysis in clean waters. The aims of this paper are to (i) improve the reliability of microplastic analysis, (ii) facilitate and improve the planning of sample preparation and microplastic detection, and (iii) provide a better understanding regarding the evaluation of already existing studies. With these aims, we hope to make an important step toward harmonization of microplastic particle analysis in clean water samples and, thus, allow the comparability of results obtained in different studies by using similar or harmonized methods. Clean water samples, for the purpose of this paper, are considered to comprise all water samples with low matrix content, in particular drinking, tap, and bottled water, but also other water types such as clean freshwater. [ABSTRACT FROM AUTHOR]

This paper presents a workflow for delineating a risk‐based area of review (AOR) to support a US Environmental Protection Agency (EPA) Class VI permit for a carbon dioxide (CO2) storage project. The approach combines semianalytical solutions for estimating formation fluid leakage through a hypothetical leaky wellbore with the results of physics‐based numerical reservoir simulations. The workflow is demonstrated using a case study for a hypothetical 180,000‐metric‐ton‐per‐year storage project located in the Plains CO2 Reduction (PCOR) Partnership region, which includes all or part of 10 states in the United States and four Canadian provinces. Under the scenario where the leaky wellbore is open to a saline aquifer (thief zone) between the overlying seal (cap rock) and the underground sources of drinking water (USDW), the risk‐based AOR is no larger than the areal extent of the CO2 plume in the storage reservoir because the pressure buildup in the storage reservoir beyond the CO2 plume is insufficient to drive formation fluids up a hypothetical leaky wellbore into the USDW. However, even under the conservative assumption that the leaky wellbore is not open to a thief zone, the incremental leakage beyond the areal extent of the CO2 plume is less than 400 m3 over 20 years. The approach outlined in this paper is designed to be protective of USDWs and comply with the Safe Drinking Water Act requirements and provisions for the EPA Class VI Underground Injection Control (UIC) Program (Class VI Rule) and North Dakota Administrative Code Chapter 43‐05‐01. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this paper, a saltwater intrusion model, in view to study the dynamics of the interface between the saltwater and the freshwater in a coastal aquifer, is established. This dynamic is caused by an injection of saltwater and a freshwater pumping through a well located in a given position. From the flow model in each phase, we defined an appropriate hypothesis to obtain our global model based only on the height of the interface. The numerical simulation of our model led us to study the effect of the parameters and obtain some empirical laws of the pollution time versus the distance well-injection area and pollution time versus the pumping flow. [ABSTRACT FROM AUTHOR]

Salt spray splashing on the structural surfaces of ships is a common difficulty in polar navigation. In this paper, experiments are designed to study the variation in the growth peak of pure water droplets on the surface of a hydrophobic coating with a contact angle of 90°, and the numerical simulation method is verified according to the experiment. The variation in the growth peak calculated by the numerical simulation is consistent with the experiment, and the calculation error of the freezing time obtained by numerical simulation is less than 10% of that of the experiment. The freezing processes of droplets with salinity levels of 0, 10, 20, 30, 40, and 10 μL on the surfaces of the hydrophilic, hydrophobic, and super hydrophobic plates are studied. The freezing time of the droplets is calculated, along with the effects of the wall temperature, surface contact angle, and salinity on the freezing time and freezing process of the droplets. The results show that the freezing time increased dramatically with increasing salinity. The influence of the contact angle and substrate temperature on the freezing process was also concentrated. All these results contribute to a better understanding of the icing mechanism on marine surfaces. [ABSTRACT FROM AUTHOR]

Salinity in deltaic systems is expected to increase in the near future due to sea level rise. This will cause severe environmental consequences because salinity can be detrimental to agriculture, aquaculture and human consumption. Tidal dynamics are important in regulating salinity in river deltas. However, there is still uncertainty about the influence of different tidal amplitudes on deltas' salinity. This paper investigates the impact of various tidal amplitudes on the spatiotemporal salinity distribution in deltas through three-dimensional idealized modelling. Numerical simulations are carried out with a common hydrograph and different tidal ranges. Both tide-influenced and river-dominated cases were considered. Results suggest that small increases in the tidal amplitude in river-dominated or low tidal regimes cases can have positive effects against salinization. Tide-induced mixing helps to increase freshwater areas and volumes. The water in the delta remains fresh for longer periods in scenarios representative of microtidal regimes. Further increases in the tidal amplitude to meso- and macrotidal levels reverse these effects and reduce freshwater areas and volumes. Results were used to test how salinity correlates with channel orders and river discharge in the presence of tides. These correlations are controlled more by bathymetry than tidal forcing. This study provides important insights into how changes in tidal range could impact spatiotemporal salinity distributions in deltas. [ABSTRACT FROM AUTHOR]

Sanctuaries devoted to Asclepius were established and operated for almost a thousand years in various Greek and Roman cities throughout the Mediterranean region. The Asclepieion sanctuary in Lentas (formerly known as Ancient Lebena) in Crete was famous for receiving water from a sacred spring. In Ancient Lebena, Levinaion was a famous centre for hydrotherapy, physiotherapy, and a psychiatric hospital. In the present paper, we aim to assess the hydrochemical status of this sacred spring that holds a prominent position in archaeological and historical studies. The main objectives of this study are: Initially, to present supervisory evidence (archaeological, geological, hydrochemical) of an area that was a water resource management model for many centuries, carrying out therapeutic work. The second objective is to present and compare hydrochemical data in the last century, i.e., from 1915 to 2021. The third objective is to highlight and warn of an incipient saltwater intrusion in the area along the Lentas coast. The fourth objective is to propose an alternative and sustainable form of water resources management in the region that requires the study and rational utilization of the sporadic small water springs in the region. Our study focuses on a basic hydrochemical analysis of spring and borehole water in the remains of Levinaion in the Lentas region, and their comparison with sparse historical data of the sacred spring water, aiming to interpret the impact of the changes in the spring water resources that occurred in recent decades due to urban modernization. Our results highlight (i) visible fluctuations in chemical composition of borehole water samples; (ii) a neutral to alkaline pH in borehole waters and an alkaline pH in spring waters; (iii) undetectable arsenic in Lentas borehole water, unlike historical data of Lentas spring water; (iv) low values of dissolved radon in Lentas borehole water and the spring water of Kefalovrysa; and (v) a timeless constant and hypothermic nature of the water of both the sacred spring and borehole of Lentas, and also of the Kefalovrysa spring. The recorded historical data, i.e., from 1915 to 1957, due to the absence of substantial anthropogenic activity in the area, can be used as reference values (natural background levels, NBLs) for the Lentas area. Our findings emerge with the need to bring again the flowing spring water of the sacred spring of Lentas in its original form through sustainable management and re-discover its beneficial therapeutical effects. [ABSTRACT FROM AUTHOR]

Given the high human demand for freshwater and its consequent scarcity, desalination processing seems to be a key solution, given the vast amount of seawater on the planet. Currently, desalination plants provide about 95 million m3/day freshwater in 177 countries worldwide. However, desalination is an energy-intensive, demanding technique that generally uses fossil fuels and contributes to global warming via greenhouse gas emissions. Freezing/melting desalination (F/M) uses about 70% less thermal energy than the boiling process. Unfortunately, this technique is rarely used, mainly because of salt separation problems at low temperatures close to 0 °C. Most models have determined their results assuming a saline concentration value of the retained liquid; however, there is a significant disagreement in this value. This study proposes a unidimensional model based on thermal and mass diffusion evolution. The model predicts the successful separation of salt-free ice to avoid salt diffusion before encapsulation; the process depends on temperature, saline gradients, and time. The calculations in this paper are based on the salt concentration in the liquid-solid interface, which has been extensively studied, achieving an accurate performance of the proposed model. [ABSTRACT FROM AUTHOR]

Aristino-Traianoupolis area hosts one of the most significant water-dominated low-temperature geothermal fields in Greece. It is located on the southwestern uplifted margin of the Tertiary Evros Delta molassic basin, 10 km east of the town of Alexandroupolis (Thrace, NE Greece). The upper hydrothermal system of the Aristino Geothermal Field (AGF), one of the most promising in continental Greece, contains fluids with temperatures ranging from 51 to 99 °C, within a series of overlapping aquifers at very low depths (100–430 m). The main geothermal anomaly for temperatures higher than 90 °C covers an area of 6 km2, to a maximum prospected depth of 500 m below ground surface. The scattered regional anomaly exceeds 50 km2 and is characterized by excessively high and abruptly changing thermal gradient (42 to 450 °C/km) and heat flow (80–800 mW/m2), that are both typical of a fault-controlled hydrothermal system. Since 1993, the AGF has undergone non-systematic geothermal investigation, with emphasis on low-depth (100–500 m) drilling. This paper provides, for the first time, a synthetic and detailed evaluation of all available temperature data gathered in the last 25 years. The steady-state temperature logs reveal the dominant role of conduction for the upper geothermal system, accompanied, in most cases, by rapidly changing and abnormally high thermal gradients (100–450 °C/km), triggered, most probably, by a deeper system of higher temperature. This hypothesis is also supported by the applied chemical geothermometers, which suggest initial fluid temperatures at 140–150 °C, the hydrochemical characteristics of the fluids hosted in the deeper and most promising investigated reservoir (ignimbrite) of the upper system, and the extrapolated temperatures from the conductive temperature–depth profiles. The lower widespread medium enthalpy hydrothermal system should extend at depths 500–1000 m within volcanics and the expected Eocene limestones and basal clastic series of the Tertiary sequence that have filled the basin. Nevertheless, these assumptions need to be verified by appropriate investigations and new drillings at depths greater than 600–700 m, which would confirm the presence of a productive medium enthalpy reservoir. [ABSTRACT FROM AUTHOR]

Although natural CO2 -rich groundwaters of eastern Belgium have been known for centuries, the exact origin of their gas is still unclear. This paper presents the results of a sampling campaign in Belgium (Spa, Stoumont, Malmedy): 30 samples of both carbogaseous and non-carbogaseous groundwaters were analyzed for major elements, CO2 content and carbon isotopic composition. Among them, 13 samples were also analyzed for 3He/4He and 4He/20Ne ratios. The combination of δ13C (between ca. -9‰ VPDB Vienna Pee Dee Belemnite and -2‰ VPDB), CO2/3He ratio (between 1.9×108 and 2.9×109) and 3He/4He (between 0.92 and 2.70 Ra) shows with a high level of confidence that the CO2 in the carbogaseous groundwater of Spa and Bru has a mantle origin. It can likely be attributed to the degassing of mantle from the neighboring Eifel volcanic fields, located at a distance of 100 km eastwards. The identity and nature of the deep-rooted fractures that act as CO2 transport pathways to the surface are still to be clarified, but several major thrust faults exist in the Rhenish Massif and could connect the Eifel volcanic fields with the studied area. [ABSTRACT FROM AUTHOR]

Impact-generated hydrothermal systems are a potential habitat for life on Earth and other planetary bodies. The ubiquity of impact craters on Mars makes them of particular interest for the search for life on this planet although their viability as a habitat is not well understood. To better understand such systems, two analogue impact structures on Earth were investigated, as their dominantly basaltic target rock makes them similar to impact structures in the Martian crust: the Vista Alegre and Vargeão Dome impact structures in Brazil. The goals of this paper are to 1) better understand the Vista Alegre and Vargeão Dome impact structures, and 2) understand how impact-generated hydrothermal systems on Earth can be compared with similar systems on Mars. To enable comparison, the software HYDROTHERM is used to reconstruct the hydrothermal evolution of both impact systems on Earth. Permeability, porosity, thermal conductivity, and initial temperature distributions are varied to simulate slow--, medium-, and fast-cooling models. The medium cooling rate models are then adapted to Martian conditions and scaled to 1×, 2×, 4×, and 8× the size on Earth, also adapting the impact energy and initial heat distribution, to check the comparability using similar target rocks. Finally, target rocks are changed to a basaltic composition only, to check how a lower-permeability Martian surface composition would affect the hydrothermal system. The models indicate between 150 and 650 thousand years (ka) of hydrothermal activity for both the Vista Alegre and Vargeão Dome impact structures. Due to the limited availability of water in the initial, high-temperature situation in the crater centre, water flux first increases and then decreases, although after 650 kyr the water flux towards the crater centre remains active in Vargeão Dome only. This sustained water flux is likely related to the low relative pressure in the crater centre due to the lack of overlying rock in comparison to outside the crater, as well as the direct connection of an underlying sandstone aquifer with high-permeability, fractured basalt in the centre of the structure. The Martian models with the same lithologies as on Earth show overall lower water flux and contain permafrost, which prevents the water flux within the aquifer from outside the crater towards the crater centre as seen in Vargeão Dome. The cooling times increase with scaling from 1× to 8× the size to ∼0.2 and 5 Myr, respectively. With only basalts in the target, cooling times reach ∼0.2 to 9 Myr. However, in that case, the water flow only remains active for up to the first Myr, and a minimum crater diameter of approximately 40 km is needed to achieve surface water fluxes close to those in Vargeão Dome and Vista Alegre. Below the Martian surface, hydrothermal system activity can persist for millions of years, providing potential for supporting life. Unfortunately, these parts of the system are currently unreachable for both sampling and spectroscopic techniques, and the short lifetime and low water fluxes at the surface related to the permafrost layers do not favour impact-generated hydrothermal systems on present-day Mars as targets for the search for life. However, these systems are highly dependent on the rock types and related permeabilities and could have provided habitats before 3.5 Ga, when the planet was warmer and liquid water was present at the surface. • This is the first fluid-flow model of terrestrial impact craters in basaltic targets. • This is the first direct comparison of fluid-flow models for impact-generated hydrothermal systems on Earth and Mars. • This is the first time a (semi)quantitative limit is set for impact-generated hydrothermal systems on Mars. • The paper provides new insights into impact-generated hydrothermal systems on Mars and their potential as a habitat. [ABSTRACT FROM AUTHOR]

This paper presents a study on the salinity determination and flow rate estimation in a two-phase air-water system. For this purpose, an automated air-water test loop capable of generating different flow patterns in a horizontal pathway was utilized to do numerous experiments at varying flow rates. A nuclear measuring setup, comprising Cs-137 and Am-241 as radiation sources, one NaI (Tl) scintillation detector to register transmission counts of Cs and three scintillator detectors for registering transmission and scattering counts from Am, was prepared. A pressure drop pipe was also employed for flow rate measurement, with MLPs were selected as the processing element. Notable innovations of this paper can be considered from two perspectives. Firstly, a novel paradigm in nuclear measurement geometry. This novelty uses the benefits of three scintillator detectors to extract features with the maximum potential for classifying and determining salinity. Secondly, there is a new method in data processing and utilizing optimum features to achieve the best performance in predicting flow rates. Results in flow rate prediction independent of salinity and flow regime indicate that the proposed paradigm and method are reliable for using in industrial fields related to multi-phase metering. • This paper proposes a novel paradigm in nuclear measurement geometry. • This paper employs seven ANNs to develop the optimal prediction model. • The combination of wavelet transform and statistical features shows the best performance to determine the flow rates. • The results indicated that the proposed prediction model achieved an MAE of less than 4/237 L/min and an MRE% of 4/842 % for predicting flow rates. [ABSTRACT FROM AUTHOR]

With the high demand for basic resources such as electricity, communication, water supply, and gas in cities, most cities in my country are vigorously developing underground integrated pipe gallery. When constructing pipe gallery in coastal areas, it is necessary to consider the impact of groundwater level on structural calculations. There is still a lack of systematic research in domestic and foreign literature. Relying on the Qingdao West Coast New Area Project, this paper uses a combination of laboratory tests and MIDAS GTS/NX numerical simulation to study the influence of groundwater in the coastal area on the stress and deformation characteristics of the integrated pipe gallery. The results show that (1) the Mises stress on the roof and bottom of the integrated pipe gallery increases continuously with the rise of the groundwater level. Due to the effect of the effective stress, the Mises stress on the side wall shows a decreasing trend. (2) Due to the influence of the construction form of the cross-section interface, the maximum principal stress of each part of the M side is always smaller than that of the N side; with the continuous increase of groundwater level, the maximum principal stress at each part of the N and M sides of the pipe gallery structure joint gradually increases. (3) The overall structure of the pipe gallery floats up. Under the action of the buoyancy force, the bottom plate moves upward, and the surface displacement rises continuously with the rise of the groundwater level. (4) When the groundwater depth is the same, the analysis of the test results and the numerical simulation calculation results are basically consistent, which further verifies the validity of the numerical simulation calculation and has reference value. (5) The engineering example shows that in order to reduce the service life of the integrated pipe gallery, the impact of groundwater on the integrated pipe gallery cannot be ignored. [ABSTRACT FROM AUTHOR]

Tahe oil field is a typical fissure cave carbonate reservoir with a temperature of up to 120~140 °C and a total salinity of formation water of (20~25) × 104 mg/L. In this paper, AM/AMPS was selected as the polymer, 1, 5-dihydroxy naphthol as the cross-linking agent, and polypropylene fiber as the system stabilizer to synthesize a novel gel plugging agent independently; the gel has good thermal stability at a high temperature of 130 °C and increased salinity of 20 × 104 mg/L, and has a dense and relatively stable three-dimensional network structure under a scanning electron microscope. The performance evaluation of the gel plugging agent indicated that: the gel dehydration rate increased gradually with the increase in temperature and salinity, making it suitable for reservoirs with temperatures below 140 °C and formation water salinity below 250,000 mg/L; the viscosity of the gel bulk was 125.3 mPa∙s, the post-gelatinizing viscosity was 42,800 mPa∙s, and the gelatinizing time at 120 °C, 130 °C and 140 °C was 10–20 h, 8–18 h, and 7–16 h, respectively. [ABSTRACT FROM AUTHOR]