The saturation of the compacted bentonite buffer in the deep geological repository can cause bentonite swelling,intrusion into rock fractures,and erosion.Inevitably,erosion and subsequent bentonite mass loss due to gr...The saturation of the compacted bentonite buffer in the deep geological repository can cause bentonite swelling,intrusion into rock fractures,and erosion.Inevitably,erosion and subsequent bentonite mass loss due to groundwater inflow can aggravate the overall integrity of the engineered barrier system.Therefore,the coupled hydro-mechanical interaction between the buffer and rock during groundwater inflow and bentonite intrusion should be evaluated to guarantee the long-term safety of deep geological disposal.This study investigated the effect of bentonite erosion and intrusion on the elastic wave propagation characteristics in jointed rocks using a quasi-static resonant column test.Jointed rock specimens with different joint conditions(i.e.joint surface saturation and bentonite filling)were prepared using granite rock discs sampled from the Korea Underground Research Tunnel(KURT)and Gyeongju bentonite.The long-wavelength longitudinal and shear wave velocities were measured under different normal stress levels.A Hertzian-type power model was used to fit the wave velocities,and the relationship between the two fitted parameters provided the trend of joint conditions.Numerical simulations using three-dimensional distinct element code(3DEC)were conducted to better understand how the long-wavelength wave propagates through wet bentonite-filled rock joints.展开更多
BACKGROUND Few studies have been conducted on sex differences in the incidence, pathophysiology, and prognosis of gastric cancer(GC).AIM To analyze the differences in GC characteristics according to sex in patients wh...BACKGROUND Few studies have been conducted on sex differences in the incidence, pathophysiology, and prognosis of gastric cancer(GC).AIM To analyze the differences in GC characteristics according to sex in patients who underwent surgical treatment for GC.METHODS A total of 2983 patients diagnosed with gastric adenocarcinoma who received surgical treatment at the Seoul National University Bundang Hospital between 2003 and 2017 were included.Baseline clinicopathological characteristics, histologic type of GC, overall and GC-specific survival rates, and associated risk factors were analyzed.RESULTS Among the 2983 patients, 2005(67.2%) and 978(32.8%) were males and females, respectively.The average age of the female group(59.36 years) was significantly younger than that of the male group(61.66 years;P < 0.001).Cancer of the gastric body(P < 0.001) and diffuse-type histology(P < 0.001) were more common in females than in males.This trend was more prominent in females younger than 60 years of age, with a significantly higher proportion of diffuse-type cancer than in the male group.Regardless of sex, diffuse-type GC was more common in younger patients, and the proportion of intestinal-type GC increased with age.The overall survival rate was significantly higher in females(P < 0.001).However, this difference disappeared for GC-specific survival(P = 0.168), except for the poor GC-specific survival rate in advanced-stage cancer(stage Ⅲ or above) in females(P = 0.045).The risk factors for GC-related mortality were older age, upper location of GC, and diffuse-or mixed-type histology.In terms of comorbidities, more males died from diseases other than GC, including other malignancies such as lung cancer, hepatocellular carcinoma, and pancreatic cancer, and respiratory diseases such as interstitial lung disease and chronic obstructive pulmonary disease, while there were relatively more cardiovascular or cerebrovascular deaths in females.CONCLUSION Sex-based differences in GC were observed in clinicopathological features, including age at diagnosis, tumor location, histologic type, survival rate, and comorbidities.展开更多
Social concerns regarding the safety of high-level radioactive waste have increased with growing public awareness of environmental issues and nuclear power.The performance assessment of deep geological disposal system...Social concerns regarding the safety of high-level radioactive waste have increased with growing public awareness of environmental issues and nuclear power.The performance assessment of deep geological disposal systems is crucial to reduce the uncertainties associated with high-level radioactive waste disposal and enhance the overall public confidence in nuclear safety.Accordingly,the Korea Atomic Energy Research Institute(KAERI)has undertaken various studies on the development of a deep geological disposal system for high-level waste and disposal safety evaluation.The KAERI Underground Research Tunnel(KURT),South Korea's only underground research laboratory dedicated to radioactive waste disposal,was constructed in 2006 and expanded in 2015.Since its construction,numerous in-situ experiments have been conducted and are currently underway in the KURT.The KURT plays a significant role in assessing the feasibility,safety,stability and appropriateness of a deep geological disposal system in South Korea and also provides an opportunity to revitalize industrial-academic-scientific cooperation between related institutions.This report summarizes two key in-situ experiments and international joint research conducted between 2007 and 2017 to assess the performance of the engineered and natural barriers of the KURT.The research experiences from the in-situ tests conducted at the KURT will provide crucial information on the safety and feasibility validation of the deep geological disposal system and will be an important contributor to the success of the Korean high-level radioactive waste disposal program in the future.展开更多
基金funding support from the Nuclear Research and Development Program of the National Research Foundation of Korea(Grant Nos.2021M2E1A1085193 and 2020M2C9A1062949).
文摘The saturation of the compacted bentonite buffer in the deep geological repository can cause bentonite swelling,intrusion into rock fractures,and erosion.Inevitably,erosion and subsequent bentonite mass loss due to groundwater inflow can aggravate the overall integrity of the engineered barrier system.Therefore,the coupled hydro-mechanical interaction between the buffer and rock during groundwater inflow and bentonite intrusion should be evaluated to guarantee the long-term safety of deep geological disposal.This study investigated the effect of bentonite erosion and intrusion on the elastic wave propagation characteristics in jointed rocks using a quasi-static resonant column test.Jointed rock specimens with different joint conditions(i.e.joint surface saturation and bentonite filling)were prepared using granite rock discs sampled from the Korea Underground Research Tunnel(KURT)and Gyeongju bentonite.The long-wavelength longitudinal and shear wave velocities were measured under different normal stress levels.A Hertzian-type power model was used to fit the wave velocities,and the relationship between the two fitted parameters provided the trend of joint conditions.Numerical simulations using three-dimensional distinct element code(3DEC)were conducted to better understand how the long-wavelength wave propagates through wet bentonite-filled rock joints.
基金Supported by National Research Foundation of Korea
文摘BACKGROUND Few studies have been conducted on sex differences in the incidence, pathophysiology, and prognosis of gastric cancer(GC).AIM To analyze the differences in GC characteristics according to sex in patients who underwent surgical treatment for GC.METHODS A total of 2983 patients diagnosed with gastric adenocarcinoma who received surgical treatment at the Seoul National University Bundang Hospital between 2003 and 2017 were included.Baseline clinicopathological characteristics, histologic type of GC, overall and GC-specific survival rates, and associated risk factors were analyzed.RESULTS Among the 2983 patients, 2005(67.2%) and 978(32.8%) were males and females, respectively.The average age of the female group(59.36 years) was significantly younger than that of the male group(61.66 years;P < 0.001).Cancer of the gastric body(P < 0.001) and diffuse-type histology(P < 0.001) were more common in females than in males.This trend was more prominent in females younger than 60 years of age, with a significantly higher proportion of diffuse-type cancer than in the male group.Regardless of sex, diffuse-type GC was more common in younger patients, and the proportion of intestinal-type GC increased with age.The overall survival rate was significantly higher in females(P < 0.001).However, this difference disappeared for GC-specific survival(P = 0.168), except for the poor GC-specific survival rate in advanced-stage cancer(stage Ⅲ or above) in females(P = 0.045).The risk factors for GC-related mortality were older age, upper location of GC, and diffuse-or mixed-type histology.In terms of comorbidities, more males died from diseases other than GC, including other malignancies such as lung cancer, hepatocellular carcinoma, and pancreatic cancer, and respiratory diseases such as interstitial lung disease and chronic obstructive pulmonary disease, while there were relatively more cardiovascular or cerebrovascular deaths in females.CONCLUSION Sex-based differences in GC were observed in clinicopathological features, including age at diagnosis, tumor location, histologic type, survival rate, and comorbidities.
基金supported by the Nuclear Research and Development Program of the National Research Foundation of Korea(2021M2E1A1085193).
文摘Social concerns regarding the safety of high-level radioactive waste have increased with growing public awareness of environmental issues and nuclear power.The performance assessment of deep geological disposal systems is crucial to reduce the uncertainties associated with high-level radioactive waste disposal and enhance the overall public confidence in nuclear safety.Accordingly,the Korea Atomic Energy Research Institute(KAERI)has undertaken various studies on the development of a deep geological disposal system for high-level waste and disposal safety evaluation.The KAERI Underground Research Tunnel(KURT),South Korea's only underground research laboratory dedicated to radioactive waste disposal,was constructed in 2006 and expanded in 2015.Since its construction,numerous in-situ experiments have been conducted and are currently underway in the KURT.The KURT plays a significant role in assessing the feasibility,safety,stability and appropriateness of a deep geological disposal system in South Korea and also provides an opportunity to revitalize industrial-academic-scientific cooperation between related institutions.This report summarizes two key in-situ experiments and international joint research conducted between 2007 and 2017 to assess the performance of the engineered and natural barriers of the KURT.The research experiences from the in-situ tests conducted at the KURT will provide crucial information on the safety and feasibility validation of the deep geological disposal system and will be an important contributor to the success of the Korean high-level radioactive waste disposal program in the future.
