Pub Date : 1900-01-01DOI: 10.25177/jeses.6.1.ra.10786
John W. Reeder
Starting 15 June 2020, a shallow earthquake swarm occurred in the Nateekin River valley just east of Makushin Volcano of Unalaska Island, Alaska, U.S.A. Focal mechanism determinations were made on the larger earthquake events. These correlated with four known fault groups originally recognized during 1980-85 field work in this region. These are (a) numerous N 54° W ± striking normal faults, (b) prominent N 74° W ± striking normal faults, (c) N 50° E ± strike-slip faults, and (d) a N 36° E ± striking reverse faults. These fault groups correlate with known dikes for the region, which suggest magmatic intrusions are associated with this earthquake swarm. These faults reflect a predictable fault structure for a regional maximum horizontal tectonic stress direction of N 54° W ± with a localized spreading rift zone associated with Makushin Volcano that is striking N 74° W ±. This rift zone has a reactivated landslide and numerous nearby small landslides caused by this June/July earthquake swarm. This swarm sheds insight into the faulting, volcanic and geothermal processes of the region. Key words: Shallow earthquake swarm in a volcanic rift zone; four different seismic focal (fault) mechanisms recognized; associated active faults and landslides observed; related Holocene dikes and volcanic activity; regional maximum horizontal tectonic stress and magmatic processes; extensive geothermal resources.
{"title":"Geologic aspects (faults, landslides and volcanic dikes) of the Nateekin River shallow earthquake swarm of 15 June 2020 near Makushin Volcano, Unalaska Island, Alaska, U.S.A.-siftdesk","authors":"John W. Reeder","doi":"10.25177/jeses.6.1.ra.10786","DOIUrl":"https://doi.org/10.25177/jeses.6.1.ra.10786","url":null,"abstract":"Starting 15 June 2020, a shallow earthquake swarm occurred in the Nateekin River valley just east of Makushin Volcano of Unalaska Island, Alaska, U.S.A. Focal mechanism determinations were made on the larger earthquake events. These correlated with four known fault groups originally recognized during 1980-85 field work in this region. These are (a) numerous N 54° W ± striking normal faults, (b) prominent N 74° W ± striking normal faults, (c) N 50° E ± strike-slip faults, and (d) a N 36° E ± striking reverse faults. These fault groups correlate with known dikes for the region, which suggest magmatic intrusions are associated with this earthquake swarm. These faults reflect a predictable fault structure for a regional maximum horizontal tectonic stress direction of N 54° W ± with a localized spreading rift zone associated with Makushin Volcano that is striking N 74° W ±. This rift zone has a reactivated landslide and numerous nearby small landslides caused by this June/July earthquake swarm. This swarm sheds insight into the faulting, volcanic and geothermal processes of the region. Key words: Shallow earthquake swarm in a volcanic rift zone; four different seismic focal (fault) mechanisms recognized; associated active faults and landslides observed; related Holocene dikes and volcanic activity; regional maximum horizontal tectonic stress and magmatic processes; extensive geothermal resources.","PeriodicalId":307656,"journal":{"name":"SDRP Journal of Earth Sciences & Environmental Studies","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130897455","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}
Pub Date : 1900-01-01DOI: 10.25177/jeses.6.1.ra.10782
J. Valette
The extraction of cashew nut shell liquid (CNSL) was investigated using five solvents (water, water-methanol mixture, acetone, methanol and hexane) under different extraction conditions. Effects of process parameters such as extraction cycle, pressure, solvent volume and extraction duration were investigated. The best yields of extraction (51.7%) were obtained with water-methanol mixture by using an accelerated solvent extractor (ASE) under pressure at 100 bars. The extraction obtained with water at atmospheric pressure was close to ASE extraction (49.8%). However, the composition of CNSL varied among these different operating conditions. Chemical composition of the extracted oil by ASE or by atmospheric pressure extraction showed minor difference in their composition. The quality of the analyzed extracts was almost equal in cardol, cardanol, anacardol and anacardic acid contents.
{"title":"Improvement of extraction methods of Malian Cashew nut shell liquid-siftdesk","authors":"J. Valette","doi":"10.25177/jeses.6.1.ra.10782","DOIUrl":"https://doi.org/10.25177/jeses.6.1.ra.10782","url":null,"abstract":"The extraction of cashew nut shell liquid (CNSL) was investigated using five solvents (water, water-methanol mixture, acetone, methanol and hexane) under different extraction conditions. Effects of process parameters such as extraction cycle, pressure, solvent volume and extraction duration were investigated. The best yields of extraction (51.7%) were obtained with water-methanol mixture by using an accelerated solvent extractor (ASE) under pressure at 100 bars. The extraction obtained with water at atmospheric pressure was close to ASE extraction (49.8%). However, the composition of CNSL varied among these different operating conditions. Chemical composition of the extracted oil by ASE or by atmospheric pressure extraction showed minor difference in their composition. The quality of the analyzed extracts was almost equal in cardol, cardanol, anacardol and anacardic acid contents.","PeriodicalId":307656,"journal":{"name":"SDRP Journal of Earth Sciences & Environmental Studies","volume":"320 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116357662","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}
Pub Date : 1900-01-01DOI: 10.25177/jeses.6.2.ra.10797
Jiting Wang
In recent years, with the rapid development of the global economy, heavy metals have been widely used in industrial production and daily life because of their unique properties. This, however, has simultaneously led to heavy metal pollution due to various reasons. After entering the aquatic environment, heavy metals are not easily decomposed by microorganisms and become toxic when they reach a certain concentration. Heavy metals can easily enter the liver and other vital organs of aquatic organisms, where they accumulate and severely affect the growth and reproduction of these organisms. They can also threaten human health through the food chain. Therefore, heavy metal pollution has potential ecological and health risks. This paper summarizes the sources and hazards of heavy metals in water, the pattern of enrichment of heavy metals in aquatic organisms, the toxic effects of heavy metals on aquatic organisms, the tolerance mechanism of aquatic animals to heavy metals, and the factors affecting the toxicity of heavy metals. The authors put forward three feasible suggestions for the study of ecotoxicological effects of heavy metals on aquatic organisms in the future. The results of this study have considerable significance for aquaculture and environmental management and even for humans.
{"title":"A review on the ecotoxicological effects of heavy metals on aquatic organisms-siftdesk","authors":"Jiting Wang","doi":"10.25177/jeses.6.2.ra.10797","DOIUrl":"https://doi.org/10.25177/jeses.6.2.ra.10797","url":null,"abstract":"In recent years, with the rapid development of the global economy, heavy metals have been widely used in industrial production and daily life because of their unique properties. This, however, has simultaneously led to heavy metal pollution due to various reasons. After entering the aquatic environment, heavy metals are not easily decomposed by microorganisms and become toxic when they reach a certain concentration. Heavy metals can easily enter the liver and other vital organs of aquatic organisms, where they accumulate and severely affect the growth and reproduction of these organisms. They can also threaten human health through the food chain. Therefore, heavy metal pollution has potential ecological and health risks. This paper summarizes the sources and hazards of heavy metals in water, the pattern of enrichment of heavy metals in aquatic organisms, the toxic effects of heavy metals on aquatic organisms, the tolerance mechanism of aquatic animals to heavy metals, and the factors affecting the toxicity of heavy metals. The authors put forward three feasible suggestions for the study of ecotoxicological effects of heavy metals on aquatic organisms in the future. The results of this study have considerable significance for aquaculture and environmental management and even for humans.","PeriodicalId":307656,"journal":{"name":"SDRP Journal of Earth Sciences & Environmental Studies","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133297122","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}
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