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The discovery of new natural gas resources in the Eastern Mediterranean fueled the tension in the region and led to a highly complicated crisis involving multiple actors. This study adopts a constructivist approach in analyzing the political economy of the Eastern Mediterranean energy crisis by relying on the role of identities and ideas in shaping economic decisions. The historical enmity between Turkey and Greece over Cyprus is at the heart of the crisis. Thus, the study focuses on the Turkey, Greece, and Cyprus triangle to reveal the impact of Turkey's image constructed by Greece and the Republic of Cyprus, on the political-economic aspect of the decisions of Greece and Greek Cypriots. To accomplish this objective, a two-stage content analysis was conducted by filtering the official statements of Greece and the RoC from their respective foreign ministries, utilizing the keyword "Eastern Mediterranean." By scrutinizing the official discourses and documents, the analysis aims to delve into the image of Turkey held by these actors. [ABSTRACT FROM AUTHOR]

Based on an elaboration of the resource potential and annual production of tight sandstone gas and shale gas in the United States and China, this paper reviews the researches on the distribution of tight sandstone gas and shale gas reservoirs, and analyzes the distribution characteristics and genetic types of tight sandstone gas reservoirs. In the United States, the proportion of tight sandstone gas in the total gas production declined from 20%--35% in 2008 to about 8% in 2023, and the shale gas production was 8 310x108 m3 in 2023, about 80% of the total gas production, in contrast to the range of 5%--17% during 2000--2008. In China, the proportion of tight sandstone gas in the total gas production increased from 16% in 2010 to 28% or higher in 2023. China began to produce shale gas in 2012, with the production reaching 250x108 m3 in 2023, about 11% of the total gas production of the country. The distribution of shale gas reservoirs is continuous. According to the fault presence, fault displacement and gas layer thickness, the continuous shale gas reservoirs can be divided into two types: continuity and intermittency. Most previous studies believed that both tight sandstone gas reservoirs and shale gas reservoirs are continuous, but this paper holds that the distribution of tight sandstone gas reservoirs is not continuous. According to the trap types, tight sandstone gas reservoirs can be divided into lithologic, anticlinal, and synclinal reservoirs. The tight sandstone gas is coal-derived in typical basins in China and Egypt, but oil-type gas in typical basins in the United States and Oman. [ABSTRACT FROM AUTHOR]

An uneven mixing of hydrogen-blended natural gas will lead to hydrogen embrittlement in distribution pipelines, thereby affecting the quality of terminal gas, and thus highlighting the importance of ensuring the uniformity of hydrogen and natural gas mixing. In this study, FLUENT software was used to simulate three different hydrogen filling modes, namely, T-tube, bending-tube, and static mixer, and the mechanisms underlying the mixing of hydrogen and natural gas under different filling modes were analyzed. In addition, we assessed the influences of gas velocity, hydrogen blending ratio, and mixer length and blade angle on the mixing effects of a static mixer. The results revealed that among the three mixing methods assessed, the static mixer has the best overall mixing effect. Increasing gas velocity was found to have no significant effect on the mixing of hydrogen and natural gas. With an increase of hydrogen blending ratio, the mixing uniformity of hydrogen and natural gas increased from 99.49% to 99.95%, whereas there was an increase from 84.12% to 99.05% when the length of static mixer was increased, and an increase from 59.53% to 99.78% in response to an increase in blade angle. Our findings in this study can provide a methodological reference for increasing the mixing uniformity of hydrogen and natural gas in hydrogen-blended natural gas pipeline networks, and thereby contribute to the safe and rapid development of the hydrogen energy industry. [ABSTRACT FROM AUTHOR]

Copyright of DYNA - Ingeniería e Industria is the property of Publicaciones Dyna SL and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper looks into natural gas as a factor influencing the dynamics of the energy market in Eastern Europe. The energy market as such is in fact the correlation between various interrelated markets which have different effects on the final consumers' prices and on the inflation. The Eastern European energy market is currently one of the fastest-growing energy markets. It consists of resource-rich and transit countries (Belarus, Bulgaria, Czech Republic, Hungary, Poland, Moldova, Romania, Russia, Slovakia and Ukraine) with a population of roughly 291 million people, that contributes significantly to the world's energy consumption and security. The dynamics of this market depend on the new infrastructure for transiting and storing natural gas as well as the big undergoing investments in renewable energy infrastructure. [ABSTRACT FROM AUTHOR]

Based on the organic geochemical data and the molecular and stable carbon isotopic compositions of natural gas of the Lower Permian Fengcheng Formation in the western Central Depression of Junggar Basin, combined with sedimentary environment analysis and hydrocarbon-generating simulation, the gas-generating potential of the Fengcheng source rock is evaluated, the distribution of large-scale effective source kitchen is described, the genetic types of natural gas are clarified, and four types of favorable exploration targets are selected. The results show that: (1) The Fengcheng Formation is a set of oil-prone source rocks, and the retained liquid hydrocarbon is conducive to late cracking into gas, with characteristics of high gas-generating potential and late accumulation; (2) The maximum thickness of Fengcheng source rock reaches 900 m. The source rock has entered the main gas-generating stage in Penyijingxi and Shawan sags, and the area with gas-generating intensity greater than 20×108 m³/km2 is approximately 6 500 km². (3) Around the western Central Depression, highly mature oil-type gas with light carbon isotope composition was identified to be derived from the Fengcheng source rocks mainly, while the rest was coal-derived gas from the Carboniferous source rock; (4) Four types of favorable exploration targets with exploration potential were developed in the western Central Depression which are structural traps neighboring to the source, stratigraphic traps neighboring to the source, shale-gas type within the source, and structural traps within the source. Great attention should be paid to these targets. [ABSTRACT FROM AUTHOR]

Copyright of Technikgeschichte is the property of Nomos Verlagsgesellschaft mbH & Co. KG and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] • Explores the impact of changes in energy sources on the economy and environment. • Focuses on highly natural gas-dependent European Union countries. • Applies novel quantile-based time series approaches (QQ, GQ, and QR). • Impact of gas alternatives varies by country, energy sources, and quantiles. • There is a trade-off for Finland and Germany in terms of the best gas alternative. This study evaluates the potential impacts of natural gas (NGC), renewable energy (RCC), and nuclear energy consumption (NCC) from an economic and environmental perspective for four European Union countries (Czechia, Finland, Hungary, and Germany), which have a reliance on Russia as well as use renewable and nuclear energy. In this context, quantile-based approaches are used; NGC, RCC, and NCC are considered as explanatory variables; and data between 1993/Q1 and 2021/Q4 is used. The findings show that (i) NGC has generally an accelerating impact on the economy and environment in all countries; (ii) RCC has a stimulating impact on the economy in Finland at all quantiles and in Czechia at higher quantiles. Also, it has a curbing impact on CO 2 emissions in Czechia at all quantiles and in Hungary and Germany at the higher quantiles; (iii) NCC has an increasing impact on the economy in Hungary and Germany at higher quantiles. Besides, it has a limiting impact on CO 2 emissions in Hungary at all quantiles, in Finland at higher quantiles, and in Czechia at middle quantiles; (iv) NGC, RCC, and NCC have a causal impact on both GDP and CO 2 emissions. The outcomes imply that the impact of the alternatives on GDP and CO 2 emissions varies by country, alternatives, and quantiles. RCC is the most suitable option for Czechia, NCC is the most suitable option for Hungary, and there is a trade-off for Finland and Germany. [ABSTRACT FROM AUTHOR]

Based on the methodology for petroleum systems and through the anatomy and geochemical study of typical helium-rich gas fields, the geological conditions, genesis mechanisms, and accumulation patterns of helium resources in natural gas are investigated. Helium differs greatly from other natural gas resources in generation, migration, and accumulation. Helium is generated due to the slow alpha decay of basement U/Th-rich elements or released from the deep crust and mantle, and then migrates along the composite transport system to natural gas reservoirs, where it accumulates with a suitable carrier gas. Helium migration and transport are controlled by the transport system consisting of lithospheric faults, basement faults, sedimentary layer faults, and effective transport layers. Based on the analysis of the helium-gas-water phase equilibrium in underground fluids and the phase-potential coupling, three occurrence states, i.e. water-soluble phase, gas-soluble phase and free phase, in the process of helium migration and accumulation, and three migration modes of helium, i.e. mass flow, seepage, and diffusion, are proposed. The formation and enrichment of helium-rich gas reservoirs are controlled by three major factors, i.e. high-quality helium source, high-efficiency transport and suitable carrier, and conform to three accumulation mechanisms, i.e. exsolution and convergence, buoyancy-driven, and differential pressure displacement. The helium-rich gas reservoirs discovered follow the distribution rule and accumulation pattern of "near helium source, adjacent to fault, low potential area, and high position". To explore and evaluate helium-rich areas, it is necessary to conduct concurrent/parallel exploration of natural gas. The comprehensive evaluation and selection of profitable helium-rich areas with the characteristics of "source-trap connected, low fluid potential and high position, and proper natural gas volume matched with helium's" should focus on the coupling and matching of the helium "source, migration, and accumulation elements" with the natural gas "source, reservoir and caprock conditions", and favorable carrier gas trap areas in local low fluid potential and high positions. [ABSTRACT FROM AUTHOR]

In the mid-21st century, natural gas will enter its golden age, and the era of natural gas is arriving. This paper reviews the development stages of global natural gas industry and the enlightenment of American shale gas revolution, summarizes the development history and achievements of the natural gas industry in China, analyzes the status and challenges of natural gas in the green and low-carbon energy transition, and puts forward the natural gas industry development strategies under carbon neutral target in China. The natural gas industry in China has experienced three periods: start, growth, and leap forward. At present, China has become the fourth largest natural gas producer and third largest natural gas consumer in the world, and has made great achievements in natural gas exploration and development theory and technology, providing important support for the growth of production and reserves. China has set its goal of carbon neutrality to promote green and sustainable development, which brings opportunities and challenges for natural gas industry. Natural gas has significant low-carbon advantages, and gas-electric peak shaving boosts new energy development; the difficulty and cost of development are more prominent. For the national energy security and harmonious development between economy and ecology under the carbon neutral goal, based on the principle of "comprehensive planning, technological innovation, multi-energy complementarity, diversified integration, flexibility and efficiency, optimization and upgrading", the construction of the production-supplystorage-marketing system has to be improved so as to boost the development of the natural gas industry. First, it is necessary to strengthen efforts in the exploration and development of natural gas, making projects and arrangement in key exploration and development areas, meanwhile, it is urgent to make breakthroughs in key science theories and technologies, so as to increase reserve and production. Second, it should promote green and innovative development of the natural gas by developing new techniques, expanding new fields and integrating with new energy. Third, there is a demand to realize transformation and upgrading of the supply and demand structure of natural gas by strengthening the layout of pipeline gas, liquefied natural gas and the construction of underground gas storage, establishing reserve system for improving abilities of emergency response and adjustment, raising the proportion of natural gas in the primary energy consumption and contributing to the transformation of energy consumption structure, realizing low-carbon resources utilization and clean energy consumption. [ABSTRACT FROM AUTHOR]

Based on the analysis of light hydrocarbon compositions of natural gas and regional comparison in combination with the chemical components and carbon isotopic compositions of methane, the indication of geochemical characteristics of light hydrocarbons on the migration features, dissolution and escape of natural gas from the Dongsheng gas field in the Ordos Basin is revealed, and the effect of migration on specific light hydrocarbon indexes is further discussed. The study indicates that, natural gas from the Lower Shihezi Formation (P1x) in the Dongsheng gas field displays higher iso-C5-7 contents than n-C5-7 contents, and the C6-7 light hydrocarbons are composed of paraffins with extremely low aromatic contents (<0.4%), whereas the C7 light hydrocarbons are dominated by methylcyclohexane, suggesting the characteristics of coal-derived gas with the influence by secondary alterations such as dissolution. The natural gas from the Dongsheng gas field has experienced free-phase migration from south to north and different degrees of dissolution after charging, and the gas in the Shiguhao area to the north of the Borjianghaizi fault has experienced apparent diffusion loss after accumulation. Long-distance migration in free phase results in the decrease of the relative contents of the methylcyclohexane in C7 light hydrocarbons and the toluene/n-heptane ratio, as well as the increase of the n-heptane/methylcyclohexane ratio and heptane values. The dissolution causes the increase of isoheptane values of the light hydrocarbons, whereas the diffusion loss of natural gas in the Shiguhao area results in the increase of n-C5-7 contents compared to the iso-C5-7 contents. [ABSTRACT FROM AUTHOR]

To improve the performance of hydrocyclones for in-situ natural gas hydrate recovery and desanding, this study analyzed the hydrocyclone's sensitivity factors, optimized the structural parameters, and investigated the adaptability to the reservoir and operating parameters through numerical simulations and experiments. Results showed that the optimal structural parameters were spiral pitch of 24 mm, vortex finder diameter of 36 mm, spigot diameter of 26 mm, number of spirals equals 5, and cone angle of 6°. Under the optimal parameter configuration, the efficiency of the hydrocyclone is exceeded 90%, and the pressure drop was within 0.5 MPa. When the inlet natural gas hydrate volume concentration, or the inlet sand volume concentration are increased, the separation efficiency and pressure drop changed only slightly. The natural gas hydrate hydrocyclone showed good adaptability to the reservoir and operating parameters. These findings provide theoretical guidance for the design and construction of natural gas hydrate in-situ separators. [ABSTRACT FROM AUTHOR]

The presence of a natural gas leak within a household carries the potential for fires and poses a risk of natural gas poisoning. Similar to how we approach other hazardous energy sources such as electricity and gasoline, it is crucial to exercise caution when dealing with natural gas exposure. To prevent potential hazards and dangerous situation, identified a smart gas detection system for rapid and accurate detection of gas leaks. The proposed gas leakage detection system combines advanced sensor technology, real-time monitoring, and automated alert mechanisms to ensure timely identification and response to gas leaks. The MQ2 sensor helps in detection of gas leakage. The MQ2 sensor possesses the capability to detect a wide range of gases, including methane, propane, carbon monoxide, and hydrogen. This versatility makes it an invaluable tool in ensuring safety and protecting against potential hazards and early identification of gas leaks. The collected data is analyzed using sophisticated algorithms to distinguish between normal background gas levels and potential leaks. NodeMCU, equipped with its Wi-Fi capabilities, functions as the central control unit of the system. The NodeMCU gathers real-time data from the gas sensors, constantly monitoring gas levels. It processes this data and sends it to the cloud or a central server using its internet connection. The system's ability to monitor in real-time ensures that any gas leaks detected are quickly reported to the relevant personnel or authorities through automated alerts. The fast notification system allows for quick actions, reducing the risks of accidents, saving lives, preventing property damage, and mitigating harm to the environment. [ABSTRACT FROM AUTHOR]

The global energy industry engages in exploration, drilling, production, and abandonment activities in pursuit of crude oil and natural gas. This paper provides a methodology to optimize the location and assignment of oil spill response containment systems to limit environmental damage. Utilizing 1,802 active offshore sites and 13 eligible service depots in the Gulf of Mexico's offshore energy basin, this study locates and assigns deployable land-based containment systems while evaluating the progressive enhancement of including additional service depots. The model solves the practical problem of locating and allocating oil spill containment systems to a global optimum. Adding service depots reduces the average distance, or travel time, of response vessels, which minimizes the dispersion of the oil spill. This study represents a critical component of a broader emergency oil spill response plan. Specifically, it addresses the preparation phase of a comprehensive oil spill response plan, which is preceded by the mitigation phase and followed by the response and recovery phases. [ABSTRACT FROM AUTHOR]

Copyright of Ankara Review of European Studies (ARES) / Ankara Avrupa Çalışmaları Dergisi (AAÇD) is the property of Ankara University European Union Research Centre and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The impact of special economic zones (SEZ) on the sustainability of their peripheral areas is rarely measured and discussed. This research was conducted to determine the sustainability level of the Arun Lhokseumawe SEZ generated to its surrounding area before and after the exhaustion of its natural gas resources. The statistical matching method and the Moran index used for the analysis involved 14 sustainability variables representing social, economic, and environmental dimensions. The method used includes building the sustainability index using village level data, statistical matching to find evidence of impact, and determination of the Moran index to describe its spatial patterns. Additionally, the index was used to describe the policy implication based on the current SEZ sustainability level. The results show that there is no upward trend in the sustainability index after three years of operation, except for an increase in the SEZ (inside) in 2018 which then declines again in 2021. This figure is lower than before natural gas depletion. It was found that, in 2008, the spatial pattern of the high sustainability index mainly spread to areas outside the Arun Lhokseumawe industrial area. Meanwhile, in 2021, the spatial pattern of a high sustainability index clustered near the Arun Lhokseumawe special economic zone. [ABSTRACT FROM AUTHOR]

The tightening in the international regulations is leading the energy production sector toward the usage of hydrogen, which is a zero-carbon energy carrier. In the field of gas turbine lifetime extension, a nonpremixed approach including hydrogen blending with conventional fuels is the most promising. However, high-temperature spots might occur, thus increasing thermo-mechanical stresses and NOx emissions. Therefore, a reliable evaluation of the impact of hydrogen blends in combustors characterized by nonpremixed flames is necessary. In the present work, a 40 MW heavy-duty multican combustor belonging to EthosEnergy is investigated by means of steady, reactive simulations by using the ANSYS® FLUENT® solver. The combustor geometry is simplified by removing the casing volume, being the flow split among the holes already available. Such simplification allows for paying major attention to the chemical kinetics thanks to the use of the extended reaction mechanism for natural gas developed by National University of Ireland Galway. Simulations include the assessment of the natural gas base load configuration together with hydrogen blends up to 50% in volume, while maintaining unaltered the turbine inlet temperature (TIT). The obtained data provide some retrofitting guidelines in the field of hydrogen usage in nonpremixed combustion and prove for a modified temperature field in the combustor core and close to the basket. A linear increase in NOx emission is also associated with hydrogen addition, thus suggesting the need for NOx abatement technologies (e.g., water injection). [ABSTRACT FROM AUTHOR]

Hydrogen as an essential part of future decarbonization of the energy industry makes it a crucial necessity to replace conventional, natural gas based concepts in gas turbine combustion. This paper presents an experimental study of a multi-tube jet flame burner. The study is carried out with natural gas and pure hydrogen fuel at gas turbine relevant conditions at atmospheric pressure. To identify key differences between hydrogen-air and natural gas-air flames on the overall robustness and flame flashback behavior, air bulk velocity (80-120 m/s), adiabatic flame temperature (1235-2089 K) and air inlet temperature (623-673 K) are varied over a wide range, covering a range of Reynolds numbers of 10,000-20,000. Depending on flame temperature, two different flame shapes are observed for natural gas-air flames. The shape of the hydrogen-air flame changes less over the range of flame temperatures tested, but is generally more compact. The process of fuel-air mixing is further investigated by concentration distribution measurements in a water tunnel setup. Therefore, planar laser-induced fluorescence is utilized for visualization. The measured concentration distributions confirm the overall good mixing quality but also give an explanation on the observed flashback behavior of the different burner designs at reacting tests. The findings of the study are composed in a flashback correlation combining the observed flashback drivers for the burner configurations investigated. [ABSTRACT FROM AUTHOR]

Based on the recent oil and gas discoveries and geological understandings on the ultra-deep strata of sedimentary basins, the formation and occurrence of hydrocarbons in the ultra-deep strata were investigated with respect to the processes of basin formation, hydrocarbon generation, reservoir formation and hydrocarbon accumulation, and key issues in ultra-deep oil and gas exploration were discussed. The ultra-deep strata in China underwent two extensional-convergent cycles in the Meso-Neoproterozoic Era and the Early Paleozoic Era respectively, with the tectonic-sedimentary differentiation producing the spatially adjacent source-reservoir assemblages. There are diverse large-scale carbonate reservoirs such as mound-beach, dolomite, karst fracture-vug, fractured karst and faulted zone, as well as over-pressured clastic rock and fractured bedrock reservoirs. Hydrocarbons were accumulated in multiple stages, accompanied by adjusting and finalizing in the late stage. The distribution of hydrocarbons is controlled by high-energy beach zone, regional unconformity, paleo-high and large-scale fault zone. The ultra-deep strata endow oil and gas resources as 33% of the remaining total resources, suggesting an important successive domain for hydrocarbon development in China. The large-scale pool-forming geologic units and giant hydrocarbon enrichment zones in ultra-deep strata are key and promising prospects for delivering successive discoveries. The geological conditions and enrichment zone prediction of ultra-deep oil and gas are key issues of petroleum geology. [ABSTRACT FROM AUTHOR]

• Effect of the operating parameters of a sweetening unit on CO 2 recovery efficiency has been studied and evaluated. • An equation relating the studied operating parameters and their interaction with CO 2 recovery efficiency was modeled. • Numerical optimization in Design Expert program is used to achieve the goal of maximizing CO 2 recovery efficiency. Amine processes are the advanced technology available today for the removal of carbon dioxide (CO 2) and hydrogen sulfide (H 2 S) acid gases. Methyldiethanolamine (MDEA) is a well-known tertiary amine used selectively for the removal of carbon dioxide from natural gas. There are many parameters that can affect the efficiency of separating these acid gases from natural gas. In this paper, we have studied, modeled, and optimized different operating parameters of sour gas feed and MDEA solution which affect the CO 2 recovery efficiency from an existing sweetening unit. These operating parameters are the sour gas feed temperature and pressure, volume ratio (%) of carbon dioxide in the feed gas, amine inlet temperature, and amine circulation rate. Actual data were collected from an industrial CO 2 sweetening unit over one year. These data were used to study the effect of the studied operating parameters on the recovery efficiency of CO 2 from the sweetening unit. All studied operating parameters were found to have an impact on the recovery efficiency of the removed gases. A response surface methodology approach was used in Design-Expert software version 13 to model the relationship between considered operating parameters and CO 2 recovery efficiency. In addition, Design Expert numerical optimization has been used to maximize CO 2 recovery efficiency. The results showed that the optimal range of sour gas feed temperature is 34.71 to 45.56 °C, sour gas feed pressure is 8.32 to 10.04 barg, the volume ratio (%) of carbon dioxide in the sour gas feed is 8.51 to 10.15, the temperature of the amine is 38.03 to 43.96 °C, and the amine circulation rate is 788.39 to 1122.35 m3/h. The presented work can be considered as a guideline for increasing the recovery efficiency of CO 2 for both new and existing sweetening units. [ABSTRACT FROM AUTHOR]

Given the increasing demand for clean natural gas energy, solidified natural gas (SNG) is regarded as a potential natural gas storage technology owing to its numerous advantages. In this work, the effects of the concentration of graphite nanoparticles (GNs) on the rate of hydrate formation, gas consumption, induction time, and morphology of methane hydrates under different pressures were studied. The results showed that under lower pressure, the low concentration of GNs increased the gas consumption of hydrates, but the hydrate formation rate decreased by 50% and the induction time increased. The addition of high concentration GNs decreased the hydrate formation rate significantly, there was no obvious induction period, and the final gas consumption changed little. At the same time, only a small amount of hydrate was formed, accompanied by a considerable volume of foam. Under higher pressure, the addition of GNs promoted the formation of hydrates, increased the rate of hydrate formation. Among them, the 0.3 wt% concentration of GNs showed the best promotion effect, and the final gas consumption was higher than that of other metal and oxide nanofluids. Therefore, under the proper pressure, using cheap GNs as promoters can not only effectively promote hydrate formation, but also save costs. [ABSTRACT FROM AUTHOR]

Natural gas (NG) represents a promising low-cost/low-emission alternative to diesel fuel when used in high-efficiency internal combustion engines. Advanced combustion strategies utilizing high EGR rates and controlled end-gas autoignition can be implemented with NG to achieve diesel-like efficiencies; however, to support the design of these next-generation NG ICEs, computational tools, including single- and multi-dimensional simulation packages will need to account for the complex chemistry that can occur between the reactive species found in EGR (including NOx) and the fuel. Research has shown that NOx plays an important role in the promotion/inhibition of large hydrocarbon autoignition and when accounted for in CFD engine simulations, can significantly improve the prediction of end-gas autoignition for these fuels. However, reduced NOx-enabled NG mechanisms for use in CFD engine simulations are lacking, and as a result, the influence of NOx chemistry on NG engine operation remains unknown. Here, we analyze the effects of NOx chemistry on the prediction of NG/oxidizer/EGR autoignition and generate a reduced mechanism of a suitable size to be used in engine simulations. Results indicate that NG ignition is sensitive to NOx chemistry, where it was observed that the addition of EGR, which included NOx, promoted NG autoignition. The modified mechanism captured well all trends and closely matched experimentally measured ignition delay times for a wide range of EGR rates and NG compositions. The importance of C2-C3 chemistry is noted, especially for wet NG compositions containing high fractions of ethane and propane. Finally, when utilized in CFD simulations of a Cooperative Fuels Research (CFR) engine, the new reduced mechanism was able to predict the knock onset crank angle (KOCA) to within one crank angle degree of experimental data, a significant improvement compared to previous simulations without NOx chemistry. [ABSTRACT FROM AUTHOR]

Putin's invasion of Ukraine has forced the EU to eradicate its energy dependence on Russia. This is a shift of historic proportions, particularly when it comes to natural gas, given the fact that Russia has been the EU's primary exporter since the collapse of the Soviet Union in 1991. By February 2023 almost all EU member states had imposed complete embargoes on the importation of Russian coal, crude oil, and oil products, whereas no consensus has thus far emerged at the EU level on the continuation of Russian gas exports. Despite the absence of a formal embargo on Russian natural gas, exports have drastically dropped since 2022, yet this does not necessarily entail that the EU will be able to achieve the goal of zero Russian gas exports by 2027, as is declared in its RepowerEU strategy. Through 2022, the EU has managed to cope with the loss of Russian gas exports by massively importing US LNG and, to a secondary extent, Norwegian pipeline gas. These exports though were contracted at a considerable premium and on a shortterm basis. Most EU states have not managed to replace Gazprom's long-term contracts with alternative gas imports that would be available at competitive prices and on a long-term basis. Herein lies an opportunity for the Republic of Cyprus (RoC), since the natural gas reserves discovered its Exclusive Economic Zone have the potential to offer a partial longterm alternative to the EU's dependency on Russia, but the window for the monetisation of these reserves is rapidly closing. Alternative EastMed exporters have already started to export to the EU, as well as to the East Med region, as early as 2020, whereas the first Cypriot exports cannot realistically reach any market before 2027. Nicosia's current plan to build a pipeline to Egypt in order to autonomously monetise the Aphrodite field is unlikely to offer Cyprus an export gateway to EU markets by 2027 and may even result to the stranding of the asset. At the same time a string of smaller discoveries in the RoC's western offshore blocks that took place between 2019-2022 are still at a very early stage of their potential development process and, if they are not developed jointly, they are also likely to be stranded. If a joint monetisation plan is indeed developed, these fields, namely Glaukos, Cronos and Zeus, are likely to begin exporting their gas by 2030 or, most likely, even later. [ABSTRACT FROM AUTHOR]

This article focuses on the changing nature of Russia-Turkey energy trade relations. The main argument of the article is that climate change, as well as EU institutions and environmental protection regulations, have been decisive in the long-term transformation of bilateral natural gas relations. The EU favors competitive market structures to combat climate change, and the EU Green Deal sets ambitious targets for renewable energy consumption. These variables establish grounds for legitimacy among EU members in the face of Russian dominance of the EU energy market. However, as discussed in this paper, the Russian government's main strategy to counter this opposition from the EU side is to circumvent the EU's institutional arrangements through its relations with Turkey. The final point to be discussed in this paper is the impact of the EU energy and environment policies on changes in Russian perceptions of Turkey. [ABSTRACT FROM AUTHOR]

Copyright of Rudarsko-Geolosko-Naftni Zbornik is the property of Faculty of Mining, Geology & Petroleum Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of DYNA - Ingeniería e Industria is the property of Publicaciones Dyna SL and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the context of the changes in the architecture of the global security of energy resources supply and the volatile changes in the natural gas market, the offshore sector of the Black Sea experienced a redesign regarding energy security. In the last ten years, the use of natural gas has increased a lot, in this sense the development of the Neptun Deep project has become a necessary variable for the consolidation of the energy security of Romania and the South-Eastern Europe region. By exploiting the potential of hydrocarbons in the Black Sea, Romania can become a regional provider of energy security. Also, in the context of the military developments between Russia and Ukraine that have led to major effects on global energy security, causing regional redefinitions in the direction of natural gas supply chains, Romania, through the development of the offshore sector in the Black Sea, can contribute to the redesign of regional energy security. Considering the significant potential of natural gas reserves that could become commercial exploitations, large-scale investments will be carried out within this project in the coming years. For this reason, a closer examination and analysis is required not only of natural gas as a resource but also of the economic consolidation and the potential for industrial rise that these investments would bring to Romania as a whole. [ABSTRACT FROM AUTHOR]

Because the helical axial flow gas-liquid mixing pump has the great advantage of conveying gas-liquid two-phase mixed medium, it has become the main core equipment for deep-sea oil and natural gas exploitation. The gas phase aggregation and bubble movement trajectory in the impeller channel have been widely studied, but the increase of medium flow resistance caused by flow separation has not been deeply discussed. Combined with the Euler multiphase flow model and the SST k-ω turbulence model, the numerical calculation of the helical axial flow gas-liquid mixed pump is carried out. Under design flow conditions Q = 100 m³/h, head H = 30 m, speed n = 4500 r/min, specific speed ns =213.6 r/min, and under different inlet gas content conditions, the influence of the bionic waveform leading edge blade on drag reduction characteristics of the helical axial flow gas-liquid mixed pump was investigated. By designing the blade with a leading-edge structure with different heights and pitches, the separation of the mixed medium and the suction surface is effectively suppressed, and the flow resistance of the medium in the 1/10 area of the inlet end of the blade is reduced. The results show that when the height A is 0.25%L and the pitch λ is 12.5%h, the maximum drag reduction rate in this region is 52.6%, the maximum increase in efficiency of the mixed pump is 2.2%, and the maximum increase in head is 4.8%. This study can provide technical support for flow drag reduction in gas-liquid mixed pump. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Economia e Sociologia Rural is the property of Sociedade Brasileira de Economia e Sociologia Rural and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper deals with issues related to the increase in the cost of purchasing energy, following the secondary effects related to the liberalization of the markets, which will lead the main clients from the business environment in Romania to conclude that the increase in the cost of energy is a consequence of the decisions established by the main players in the market, those who provide energy and natural gas, decisions aimed at maximizing their profit. In a much more detailed research, a series of remarks can be made, such as that at the basis of the increase in the purchase regarding the fluctuations in the cost of natural gas cost variations of energy and natural gas that consumers have to bear, there are a multitude of aspects imposed by the European Union. and energy, fluctuations that have proven to have created fluctuations in the business environment in our country over time. Following the research carried out, we can conclude that the main causes of the energy and natural gas market that create imbalances in the business environment are: - stock market fluctuations which in the current context have proven to be very dynamic and very unpredictable in extremely sudden changes; - energy import and transformations generated by cross-border flows; - the return to the consumption recorded before the pandemic period; - the reorganization of the geopolitical space based on the decisions imposed by the Russian Federation has a very big impact; - non-exploitation of natural gas stocks from warehouses to the maximum. [ABSTRACT FROM AUTHOR]

Copyright of Economía, Sociedad y Territorio is the property of El Colegio Mexiquense and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The partial oxidation of natural gas in HCCI engines in terms of a polygeneration process could be a promising technology to flexibly produce useful chemicals, heat, and work, depending on demand. Because natural gas is relatively inert, high intake temperatures or compression ratios are required to initiate its conversion which can result in a lower lifetime of the engine. Alternatively, small amounts of more reactive species such as ozone can be added to the initial mixture to provide radicals at more moderate conditions and initiate the main ignition. In this study, plug-flow reactor experiments are performed to assess the influence of ozone on the fuel conversion and product formation during the partial oxidation of methane and natural gas. Experiments are performed in the temperature range of 373 K to 973 K at 4 bar and equivalence ratios of 2. Molecular-beam mass spectrometry coupled with electron ionization is used as analytical technique to detect the mixture composition at the outlet of the reactor. The results show that even very small amounts of ozone can help to shift the conversion onset to much lower temperatures and increase the yields of useful chemicals. The data can further be used to improve reaction mechanisms describing the conversion of hydrocarbons in the presence of ozone. A literature ozone reaction mechanism has been implemented in two recent hydrocarbon mechanisms and the results of simulations using these mechanisms are compared to the experimental data with respect to the low-temperature intermediates which influence ignition. Predictions differ substantially from the experimental results identifying starting points for further investigations. The speciation data provided in this work contribute to extending the reaction kinetics of ozone assisted fuel conversion to higher pressure. [ABSTRACT FROM AUTHOR]

Gas injection has emerged over the recent decades as a promising technology to enhance oil recovery in various fields worldwide. The efficiency and success of a gas injection operation can be assessed through a number of vital experimental studies. Interfacial Tension (IFT) between the injected gas and the displacing fluid is a key parameter playing an eminent role in the foregoing studies. The main scope of this work is making a progress in modeling the IFTs between diverse n-alkanes and Methane (CH 4), Carbon Dioxide (CO 2), and Nitrogen (N 2) natural gases. For this purpose, two smart AI-based approaches of Cascaded Feedforward Neural Network (CFNN) and Decision Tree Learning (DT) were used to simultaneously model the IFTs between foregoing immiscible binary systems as a function of pressure, temperature, the gases properties, and the properties of the liquid. Several statistical measures and graphical descriptions were employed to aid the accuracy analysis of the proposed models. Both developed CFNN and DT networks represented desirable close-to-reality predictions in all binary systems. Besides, CFNN established itself as the most robust model for all studies binary systems with RMSE values of 0.5924, 0.5649, and 0.5870 mN/m, and R2 values of 0.9902, 0.9910, and 0.9904 for the train, test, and overall data, respectively. [ABSTRACT FROM AUTHOR]

Natural gas has been increasingly used as a source of energy and presents itself as a strong trend for the future. In this context, regarding the high cost of installing pipelines, the design of gas networks requires highlight quality solutions, relating not only financial indicators but also reliability and security concerning demand. Thus, this paper proposes an approach for the design of natural gas networks under conditions of uncertainty of load evolution over a time horizon. A predefined network topology is assumed, where the pipe diameters define the design variables. We propose a Multiobjective Variable Neighborhood Search (MOVNS)-based algorithm, which is evaluated considering a set of test instances defined from the TSPLIB library data. The proposed methodology is also applied to a real case study being the results compared to those obtained by three engineers of a gas company with six years of experience on average. The solutions are investigated from a dominance analysis perspective, considering the criteria: installation cost, minimum gas pressure, feasibility rate, average cost of failure, and sensitivity. The results indicate solutions relatively different from those obtained by the engineers, presenting more robust and safe networks under conditions of uncertainties of load evolution. [ABSTRACT FROM AUTHOR]

Russia is the main supplier of fossil energy to European countries. The impact of sanctions on fossil energy trade under the background of the Russia-Ukraine conflict has attracted global attention. Based on the data on fossil energy trade in 2020, this study simulates the impact of sanctions on national trade and global fossil energy trade patterns based on complex network theory and cascading failure model. In terms of negative impact, the crude oil trade has the largest potential impact, the natural gas trade has the largest direct loss and the coal trade has the least impact. To mitigate the impact of sanctions, Russia may shift its fossil-energy export focus to China and other Asian countries. The positive impact analysis shows that crude oil is the main source of benefits for energy exporting countries and the United States will become the biggest beneficiary among energy exporting countries. In addition, the study found that sanctions reshaped the pattern of global fossil energy trade, improved the trade efficiency and energy anti-control ability of European countries, and promoted the transfer of energy control centres from Europe to Asia. It is of great significance to study the impact of sanctions on global fossil energy trade to deal with geopolitical shocks, formulate energy trade policies and manage energy risks. • The sanctions have caused huge direct losses to the gas trade. • The biggest potential impact is on trade in crude oil. • Crude oil is a major source of profit for energy exporters. • The United States will be the biggest beneficiary. • Sanctions promoted the transfer of energy control centers from Europe to Asia. [ABSTRACT FROM AUTHOR]

The Russian-Ukrainian dispute over the natural gas transit and the subsequent disruptions in natural gas supply to some countries in South-East Europe (SEE) in 2006 and 2009 attracted considerable public and academic attention and it wouldn't be overstated to say that they have changed the direction of the entire energy policy of the European Union. Sixteen years after the first gas crisis, in light of the current energy crises and the military conflict between Ukraine and the Russian Federation, this paper attempts to illustrate the trends in the natural gas sector development in South-East Europe, to evaluate whether and how the role of the Russian natural gas supplies in the region's energy security has changed and to examine what measures have been taken for the security of natural gas supplies in the region over the years. The results show that although the amount of Russian natural gas delivered to the SEE countries still represents the greatest share of their total gas supplies, concerns over possible disruptions have been addressed by developing the interconnectivity in the region and commissioning new infrastructure creating alternative options for the routes and sources of supply. Nevertheless, there is still what to expect in regard to interconnectivity and market integration of the Western Balkans. [ABSTRACT FROM AUTHOR]

For the model of a multi-node energy market, the problem of maximizing social welfare is considered. Social welfare refers to the difference between the total utility of consumption and total production and transportation costs. Algorithms for solving this problem are proposed in our previous papers. These algorithms can be used to assess the prospects for gasification of arbitrary non-gasified regions of the country, if estimates of the initial parameters of the model are known - the functions of production costs and demand in nodes and the functions of transmission costs in lines. In this paper, methods for obtaining such estimates are proposed, as well as the results of the analysis of the prospects for gasification of Irkutsk oblast obtained using the described approaches are presented. [ABSTRACT FROM AUTHOR]

While migrating, animals make directionally persistent movements and may only respond to human‐induced rapid environmental change (HIREC), such as climate and land‐use change, once a threshold of HIREC is surpassed. In contrast, animals on other seasonal ranges (e.g., winter range) make more localized and tortuous movements while foraging and may have the flexibility to adjust the location of their range and the intensity of use within it to minimize interactions with HIREC. Because of these seasonal differences in movement, animals on seasonal ranges should avoid areas that contain any level of HIREC, however, during migration, animals should use areas that contain low levels of HIREC, avoiding it only once a threshold of HIREC has been surpassed. We tested this hypothesis using a decade of GPS collar data collected from migratory mule deer (Odocoileus hemionus; n = 56 migration, 143 winter) and pronghorn (Antilocapra americana; n = 70 migration, 89 winter) that winter on and migrate through a natural gas field in western Wyoming. Using surface disturbance caused by well pads and roads as an index of HIREC, we evaluated behavioral responses across three spatial scales during winter and migration seasons. During migration, both species tolerated low levels of disturbance. Once a disturbance threshold was surpassed, however, they avoided HIREC. For mule deer, thresholds were consistently ~3%, whereas thresholds for pronghorn ranged from 1% to 9.25% surface disturbance. In contrast to migration, both species generally avoided all levels of HIREC while on winter range. Our study suggests that animal responses to HIREC are mediated by season‐specific movement patterns. Our results provide further evidence of ungulates avoiding human disturbance on winter range and reveal disturbance thresholds that trigger mule deer and pronghorn responses during migration: information that managers can use to maintain the ecological function of migration routes and winter ranges. [ABSTRACT FROM AUTHOR]

Supersonic separation utilizes the cryogenics created by gas expansion to purify the mixture. This method is a novel carbon capture scheme. In this work, the models of N 2 -CO 2 (flue gas) and CH 4 -CO 2 (natural gas) are established to calculate the condensation flow. The condensation behavior of CO 2 in natural gas and flue gas is clarified respectively, and the difference between the two is compared for the first time. Under the same conditions, CO 2 in flue gas reaches the limit non-equilibrium state first, forming non-equilibrium condensation with limit nucleation rate of 7.78 × 1020 m−3s−1 and maximum droplet growth rate of 8.19 × 10−3 m s−1. However, the maximum droplet growth rate in natural gas is only 2.22 × 10−3 m s−1, which implies that the interphase mass transfer rate in flue gas is larger during the CO 2 condensation. In addition, the condensation behavior of CO 2 in natural gas is more sensitive to the changes of inlet parameters. This work provides an invaluable contribution to the development of supersonic carbon capture. • A Technology benefiting the decarbonization of natural gas and flue gas. • Non-equilibrium condensation of CO 2 in natural gas and flue gas. • Condensation of CO 2 in flue gas has a higher interphase mass transfer rate. • Condensation of CO 2 in natural gas is sensitive to inlet pressure and temperature. • Reducing inlet temperature is more effective for CO 2 capture in natural gas. [ABSTRACT FROM AUTHOR]