AIMS Geosciences最新文献_第2页

Minimizing the displacement of integrated system of wind and tidal turbines based on the soil types under cyclic loads 循环荷载作用下基于土壤类型的风潮轮机综合系统位移最小化研究

IF 1.3

AIMS Geosciences Pub Date : 2023-01-01 DOI: 10.3934/geosci.2023028

Navid Majdi Nasab, A. Wang

{"title":"Minimizing the displacement of integrated system of wind and tidal turbines based on the soil types under cyclic loads","authors":"Navid Majdi Nasab, A. Wang","doi":"10.3934/geosci.2023028","DOIUrl":"https://doi.org/10.3934/geosci.2023028","url":null,"abstract":"Hybrid offshore platforms are complex structures that need to tolerate cyclic loads. These loads occur when the turbine is working between cut-in and cut-out speeds and depend on the turbine's rotational speeds. However, selecting a proper soil for the structure to be secured in is very important for the stability of the hybrid system. This study aimed to calculate the displacement of an integrated offshore structure capable of supporting a hybrid assembly of one wind plus two tidal turbines under cyclic loads. The monopile has been found to be a suitable foundation type, as the most inexpensive solution in water depths less than 30 meters, for integrating both types of turbines. The deflection of the structure was compared for different types of soil with finite element analysis. Several simulations were conducted using OPTUM G3 software for calculating the stability of each type of soil in the rotational speed range of turbines. The results enable determining the amount of deflection for each soil type. The displacement range for soft clay is 0.0052 to 0.0098 m, and displacement is between 0.007 and 0.0158 m for medium sand. The minimum displacement of firm clay, which is 0.0115 meters at 5 rpm, is higher than all minima of other soil types. Thus, soft clay and medium sand show more stability, and firm clay is less stable in the rotational speed range of the turbines.","PeriodicalId":43999,"journal":{"name":"AIMS Geosciences","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70251986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Prioritizing climate adaptation at the local level in Ghana 优先考虑加纳地方一级的气候适应

AIMS Geosciences Pub Date : 2023-01-01 DOI: 10.3934/geosci.2023033

Kirk B Enu, Albert Ahenkan, Emmanuel Ackom

{"title":"Prioritizing climate adaptation at the local level in Ghana","authors":"Kirk B Enu, Albert Ahenkan, Emmanuel Ackom","doi":"10.3934/geosci.2023033","DOIUrl":"https://doi.org/10.3934/geosci.2023033","url":null,"abstract":"<abstract> <p>The increasing intensity and frequency of climate impacts exacerbate pressures on front-line local communities. This calls for location-specific adaptation strategies. Alignment of strategies with respective National Climate Change Strategy is key for the overall sustainability of initiatives and local communities. The work presented in this paper examines the adoption and prioritization of climate adaptation policies at the local level based on a case study of the Adansi North District (AND) in Ghana. An assessment of the extent to which climate adaptation policies are captured and budgeted for was done via a review of the district’s medium-term development and key political actors were interviewed to assess the level of priority they place on climate adaptation. Findings from the study reveal that 41% of the locally adopted policies directly align with stipulated national level policies. We attribute the adoption of climate policies in AND to local political actors having higher education which has afforded them good understanding of the climate change phenomenon, being experienced professionals and having to work within institutional rubrics that make climate policy formulation a requirement. However, little priority is given to these policies for implementation, mainly through the non-allocation of funds. We account for this with the weak environmental advocacy in the district and exchange between actors on adaptation. Furthermore, partisan actors who already wield veto powers and can promote policies that may not necessarily support adaptation measures, often do so, since their interest is to become popular among electorates who also prefer infrastructure over environmental policies. We conclude that although climate adaptation policies are fairly adopted and budgeted for in AND, they have not received commensurate priority for implementation. Recommendations are proposed for addressing this.</p> </abstract>","PeriodicalId":43999,"journal":{"name":"AIMS Geosciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135445080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on the spatial variation of sensitivity of soil nutrient system in Xinjiang, China 新疆土壤养分系统敏感性的空间分异研究

AIMS Geosciences Pub Date : 2023-01-01 DOI: 10.3934/geosci.2023034

Yang Sheng, Dehua Sun, Weizhong Liu

{"title":"Study on the spatial variation of sensitivity of soil nutrient system in Xinjiang, China","authors":"Yang Sheng, Dehua Sun, Weizhong Liu","doi":"10.3934/geosci.2023034","DOIUrl":"https://doi.org/10.3934/geosci.2023034","url":null,"abstract":"<abstract> <p>Previous studies have explored the long time series and large-scale cultivated land nutrient sensitivity and its spatial differentiation characteristics in arid zones from human activities in the context of climate change. This study is based on 10-year interval data on soil nutrient content of cultivated land in the oasis in Xinjiang, China, cultivated land use intensity (LUI) and climate data sets. Using sensitivity and GIS analysis methods, this paper studies soil nutrient sensitivities and their spatial distribution patterns in the context of LUI and climate change. The results showed significant response differences and spatial heterogeneity regarding the sensitivity of soil nutrient systems to LUI and climate change. Among them, soil nutrients were the most sensitive to temperature changes, followed by LUI, while precipitation was the weakest. Soil nutrient sensitivity showed a decreasing spatial distribution pattern from the northeast to the southwest. The soil nutrient system had a strong adaptability to LUI and climate change. However, there were differences in different sensitivity states. These results provide scientific guidance for the spatial selection and implementation of soil fertility enhancement and land remediation projects in similar arid areas.</p> </abstract>","PeriodicalId":43999,"journal":{"name":"AIMS Geosciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136303868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Design basis for Arctic infrastructure facilities 北极基础设施设计基础

IF 1.3

AIMS Geosciences Pub Date : 2023-01-01 DOI: 10.3934/geosci.2023006

Liv Brita Hætta Myrmel, O. Gudmestad

{"title":"Design basis for Arctic infrastructure facilities","authors":"Liv Brita Hætta Myrmel, O. Gudmestad","doi":"10.3934/geosci.2023006","DOIUrl":"https://doi.org/10.3934/geosci.2023006","url":null,"abstract":"A discussion related to the selection of a proper design basis for Arctic infrastructure facilities is presented. The design basis, which must be sufficiently robust to ensure safe operations of the facilities during their planned lifetime, should include relevant information available from the local and indigenous people of the area. The need to properly document all data and assumptions made when preparing the design basis is highlighted, and it is emphasized that, in the case of the upgrading of the facilities, all new data collected must be included in the database. Documentation of all updating is necessary and must be available to all involved during maintenance activities and for possible later upgrading of the facilities. This database must be available digitally, as access to the basics for the design may be of particular concern in the sparsely populated Arctic region, where the distribution of paper copies takes a long time, particularly in the case of emergency situations. Therefore, this database must be protected from cyberattacks. A \"Plan B\" is needed to ensure that a backup of the fully updated design basis documents, as well as documentation of the \"as built\" facilities, is available at any time.","PeriodicalId":43999,"journal":{"name":"AIMS Geosciences","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70250377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Theoretical evaluation of the power efficiency of a moored hybrid floating platform for wind and wave energy production in the Greek seas 希腊海域用于风能和波浪能源生产的系泊混合浮动平台功率效率的理论评估

IF 1.3

AIMS Geosciences Pub Date : 2023-01-01 DOI: 10.3934/geosci.2023009

Kimon Kardakaris, D. Konispoliatis, T. Soukissian

{"title":"Theoretical evaluation of the power efficiency of a moored hybrid floating platform for wind and wave energy production in the Greek seas","authors":"Kimon Kardakaris, D. Konispoliatis, T. Soukissian","doi":"10.3934/geosci.2023009","DOIUrl":"https://doi.org/10.3934/geosci.2023009","url":null,"abstract":"In this study, an extreme value analysis of wind and wave parameters is presented for three specific locations in the Greek seas that are known to be advantageous in terms of joint power production (both offshore wind and wave) and bathymetric conditions. The analysis is conducted via the Peak-Over-Threshold method, examining wind speed, significant wave height and peak wave period data from the ERA5 reanalysis dataset. Moreover, a multi-purpose floating platform suitable for offshore energy production is presented, which combines wind and wave energy resources exploitation and can be adequately utilized at the selected locations. The analysis is built to incorporate the solutions of the diffraction, motion-dependent and pressure-dependent radiation problems around the floating structure, along with the mooring line and wind turbine (WT) characteristics. Subsequently, a coupled hydro-aero-elastic analysis was performed in the frequency domain, while a dynamic analysis was conducted in order to evaluate the mooring characteristics. Lastly, offshore wind output and absorbed wave energy values were estimated, and different types of mooring systems were compared in terms of efficiency. It has been concluded that the wind energy capacity factor is higher than 50% in all the examined locations, and by the mooring system comparison, the tension-leg platform (TLP) represents the best-case scenario for wave energy absorption.","PeriodicalId":43999,"journal":{"name":"AIMS Geosciences","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70250439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Thermodynamic and geochemical studies of formation water in Rag-e Sefid oil and gas field, Iran 伊朗拉格-塞菲德油气田地层水热力学与地球化学研究

IF 1.3

AIMS Geosciences Pub Date : 2023-01-01 DOI: 10.3934/geosci.2023031

Seyed Hossein Hashemi, Abas Niknam, A. K. Torghabeh, Nuno Pimentel

{"title":"Thermodynamic and geochemical studies of formation water in Rag-e Sefid oil and gas field, Iran","authors":"Seyed Hossein Hashemi, Abas Niknam, A. K. Torghabeh, Nuno Pimentel","doi":"10.3934/geosci.2023031","DOIUrl":"https://doi.org/10.3934/geosci.2023031","url":null,"abstract":"Nowadays, the concentration of mineral cations and anions in the formation water of oil and gas fields is a challenging issue for oil industry technicians managing the formation of mineral deposits during water injection operations. For this reason, the analysis of formation water mineral ions during exploitation operations can be a valuable solution for the efficient management of oil production. Therefore, in this research, the thermodynamic and geochemical evaluation of formation water in the Reg-e Sefid oil and gas field is considered. Based on the results of this study, the formation of calcium sulfate and calcium carbonate can be expected due to the concentration of mineral ions dissolved in the formation water in the Reg-e Sefid oil and gas field according to the StimCad2 software. Also, based on the evaluation of ion ratios, the studied oil and gas field formation has ideal conditions for hydrocarbon production. Based on the results obtained from the comparison of the water and rock formation of the Rag-e Sefid oil and gas field, the source of ions (except calcium and magnesium ions) is related to ancient sea water.","PeriodicalId":43999,"journal":{"name":"AIMS Geosciences","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70251621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Post-pandemic scenarios. The role of the Italian National Recovery and Resilience Plan (NRRP) in reducing the gap between the Italian Central-Northern regions and Southern ones 流行后的场景。意大利国家恢复和恢复力计划在缩小意大利中北部地区与南部地区之间差距方面的作用

IF 1.3

AIMS Geosciences Pub Date : 2023-01-01 DOI: 10.3934/geosci.2023030

Stefania Palmentieri

{"title":"Post-pandemic scenarios. The role of the Italian National Recovery and Resilience Plan (NRRP) in reducing the gap between the Italian Central-Northern regions and Southern ones","authors":"Stefania Palmentieri","doi":"10.3934/geosci.2023030","DOIUrl":"https://doi.org/10.3934/geosci.2023030","url":null,"abstract":"The Covid-19 pandemic and the Ukraine crises fit into the difficult Italian context, which have already been marked by a deep socioeconomic gap between the Centre-North and the South of the country. After a brief examination of the causes that have led to this gap, starting from the analysis of geographical studies on the subject and elaborations of data provided by important research centres in the field, this study aims to point out the sectors of Southern Italy present greater criticalness and backwardness compared to the rest of the country. Then, we identify the most suitable programmatic lines to increase investments in such sectors, as already provided for the Italian National Recovery and Resilience Plan (NRRP—in Italy PNRR), a program with which the government intends to manage Next Generation EU funds or NGEU (the economic recovery and revitalization tool introduced by the European Union to restore the losses caused by the pandemic). The article concludes with a reflection on the main reasons for the difficulties that the NRRP is encountering by implementing this program, mainly related to the insufficient allocation of resources and competencies of the territorial authorities that are entrusted with the task of managing and planning policies to rebalance the country*s growth potential.","PeriodicalId":43999,"journal":{"name":"AIMS Geosciences","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70252060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Geotechnical characterization of index and deformation properties of Stockholm clays 斯德哥尔摩粘土指标及变形特性的岩土力学表征

IF 1.3

AIMS Geosciences Pub Date : 2023-01-01 DOI: 10.3934/geosci.2023015

S. Hov, David Gaharia

{"title":"Geotechnical characterization of index and deformation properties of Stockholm clays","authors":"S. Hov, David Gaharia","doi":"10.3934/geosci.2023015","DOIUrl":"https://doi.org/10.3934/geosci.2023015","url":null,"abstract":"This paper describes the geotechnical characteristics of index and deformation properties of Stockholm clays. These clays exhibit large variations both geographically and with depth. The clays range from highly organic clays with high plasticity to silty clays with low plasticity. First, the geological conditions of the clays are outlined to qualitatively explain the typical soil stratigraphy encountered in the Stockholm area. Second, two large generic databases are presented, containing 3,500 and 1,600 data points, respectively. The data originates from routine testing and constant rate of strain oedometer tests conducted in commercial projects. The data is analyzed and compared with results from high quality block sampling. It is seen that a common feature of the clays are low undrained shear strengths, and consequently low yield stresses and oedometer moduli. Further, several deformation properties such as preconsolidation pressure and several oedometer moduli is shown to depend on the soils natural water content and its plasticity. Differences in sample quality is shown to highly affect some properties, highlighting the importance of quality sampling and handling of samples. Criteria for sample quality for this type of clay is proposed based on the oedometer moduli before and after the preconsolidation pressure. The paper can hopefully work as a useful reference to engineers working on similar soils worldwide.","PeriodicalId":43999,"journal":{"name":"AIMS Geosciences","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70250158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimistic expectations and life satisfaction as antecedents of emigration attitudes among Bulgarian Millennials and Zoomers 乐观的期望和生活满意度是保加利亚千禧一代和千禧一代移民态度的先决条件

IF 1.3

AIMS Geosciences Pub Date : 2023-01-01 DOI: 10.3934/geosci.2023016

Diana I Bakalova, Ekaterina E Dimitrova

{"title":"Optimistic expectations and life satisfaction as antecedents of emigration attitudes among Bulgarian Millennials and Zoomers","authors":"Diana I Bakalova, Ekaterina E Dimitrova","doi":"10.3934/geosci.2023016","DOIUrl":"https://doi.org/10.3934/geosci.2023016","url":null,"abstract":"The purpose of this paper is to examine the predictive power of optimistic expectations and satisfaction with life in the country of origin and residence—Bulgaria, over attitudes towards emigration among young Bulgarians with regard to their generational belonging and age differences (i.e. Generation Y or Millennials and Generation Z or Zoomers). Although the correlation between satisfaction with life and migration (attitudes) has been studied in many countries, it has not been examined to date in Bulgaria (a sending, rather than receiving Eastern European country) in the light of optimistic expectations and age differences. Within a cross-sectional survey (N = 1200), representative of young Bulgarians aged 18–35 years—Zoomers aged 18–25 years (N = 444) and Millennials aged 26–35 years (N = 756), carried out in September-October 2021, optimistic expectations for individual development in Bulgaria, satisfaction with life in the country and emigration attitudes were measured using originally designed scales. The findings suggest that the more optimistic expectations about one's own career development and material security in the country are associated with higher satisfaction with life in Bulgaria and reasonably, with more negative attitudes towards emigration. Interestingly, optimistic expectations turned out a stronger antecedent of Zoomers' emigration attitudes compared to those of Millennials and life satisfaction—a stronger predictor of Millennials' emigration attitudes compared to those of Zoomers. Although no significant age differences in life satisfaction were found, Zoomers turned out significantly more optimistic about their future in the country, but also more attuned to emigration compared to Millennials. Young people with previous emigration experience were found to be significantly more likely to emigrate in comparison to those without prior emigration experience. The findings have some important interdisciplinary implications, both for psychological theory and for demographic policy.","PeriodicalId":43999,"journal":{"name":"AIMS Geosciences","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70250319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Prediction of blast-induced air overpressure using a hybrid machine learning model and gene expression programming (GEP): A case study from an iron ore mine 利用混合机器学习模型和基因表达编程(GEP)预测爆炸引起的空气超压:以某铁矿为例

IF 1.3

AIMS Geosciences Pub Date : 2023-01-01 DOI: 10.3934/geosci.2023019

Mohammad Mirzehi Kalateh Kazemi, Zohreh Nabavi, M. Khandelwal

{"title":"Prediction of blast-induced air overpressure using a hybrid machine learning model and gene expression programming (GEP): A case study from an iron ore mine","authors":"Mohammad Mirzehi Kalateh Kazemi, Zohreh Nabavi, M. Khandelwal","doi":"10.3934/geosci.2023019","DOIUrl":"https://doi.org/10.3934/geosci.2023019","url":null,"abstract":"Mine blasting can have a destructive effect on the environment. Among these effects, air overpressure (AOp) is a major concern. Therefore, a careful assessment of the AOp intensity should be conducted before any blasting operation in order to minimize the associated environmental detriment. Several empirical models have been established to predict and control AOp. However, the current empirical methods have many limitations, including low accuracy, poor generalizability, consideration only of linear relationships among influencing parameters, and investigation of only a few influencing parameters. Thus, the current research presents a hybrid model which combines an extreme gradient boosting algorithm (XGB) with grey wolf optimization (GWO) for accurately predicting AOp. Furthermore, an empirical model and gene expression programming (GEP) were used to assess the validity of the hybrid model (XGB-GWO). An analysis of 66 blastings with their corresponding AOp values and influential parameters was conducted to achieve the goals of this research. The efficiency of AOp prediction methods was evaluated in terms of mean absolute error (MAE), coefficient of determination (R2), and root mean square error (RMSE). Based on the calculations, the XGB-GWO model has performed as well as the empirical and GEP models. Next, the most significant parameters for predicting AOp were determined using a sensitivity analysis. Based on the analysis results, stemming length and rock quality designation (RQD) were identified as two variables with the greatest influence. This study showed that the proposed XGB-GWO method was robust and applicable for predicting AOp driven by blasting operations.","PeriodicalId":43999,"journal":{"name":"AIMS Geosciences","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70251108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3