상하수도 미래비젼과 대한상하수도학회의 역할

김건하,현인환 대한상하수도학회 2018 상하수도학회지 Vol.32 No.6

Since its foundation in September 1986, the Korean Society of Water and Wastewater has made a significant contribution to the water sector in Korea over the past 30 years. The 30th anniversary commemorative committee reviewed the establishment goal of the society and its development strategy for organization and present the "Future Vision of Korean Society of Water and Wastewater" for the next 30 years. The future vision of the society is defined as "Aiming for the healthy life and preservation of the environment through the development of water and wastewater technology and experience." Promotion strategies for implementing the future vision are as follows: 1. Leading water and wastewater technology, 2. Develop water and wastewater policy, 3. Strengthen water and wastewater capacity, 4. Reinforce institutional governance. The driving target to be achieved through the implementation strategy is "To lead the global standards of water and wastewater." We also presented national issue, policy issue, and technical issues in the water sector. Climate change, unified Korea, water safety, and national welfare were selected as national issues related to water and wastewater. This approach was taken from the perspective of policy consumers such as citizens, civil society, experts, and local government/industry. By presenting policy issues and technical issues that address national issues, authors have proposed a future policy direction for the Korean Water and Wastewater Society to make critical contributions to national development.

가축 매몰지 사후관리 방법

김건하 한국환경농학회 2011 한국환경농학회 학술대회집 Vol.2011 No.1

IWA DipCon 2003 학술대회 참가기

김건하 대한토목학회 2003 대한토목학회지 Vol.51 No.9

Sustainability of the In Situ Bio-barriers for Contaminant Containment in Residual Soils

김건하,Jong Heun Kim 대한토목학회 2004 KSCE JOURNAL OF CIVIL ENGINEERING Vol.8 No.2

An iterative dynamic condensation method for the model reduction is presented in this paper. Dynamic condensation method has been widely applied to large finite element models for faster computation of the natural frequencies and mode shapes. It has also been used in correlation of test-analysis models, vibration control, and structural dynamic optimization. Based on the subspace iteration method, an iterative dynamic condensation technique is employed. The proposed method has three advantages compared with other iterative schemes proposed in the past: (1) The convergence is much faster than all these methods, especially when the eigenpairs of the reduced model are close to those of the full model. (2) Since the dynamic condensation matrix is independent of the eigenpairs of the reduced model, it is unnecessary to calculate the stiffness and mass matrices in every iteration. (3) The convergence of the iterative scheme can be proved simply. Two iteration schemes, which are based on the convergence of the eigenvalues of the reduced model, are introduced. Numerical examples are presented to verify the effectiveness of this technique.

Effects of methanesulfonic acid on electrolyte for vanadium redox flow batteries

김건하,김영권,김태은,권경중 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.99 No.-

Methanesulfonic acid (MSA) is investigated as an additive for improving the thermal stability andelectrochemical property of the vanadium redoxflow battery (VRFB) electrolyte. The effect of MSA on thethermal stability of the electrolyte is estimated by a storage test, inductively coupled plasma massspectrometry, and ultraviolet–visible spectrometry. Thermal stability tests show that MSA delays theformation of precipitates. The precipitates formed from the electrolyte are analyzed by X-ray diffraction,scanning electron microscopy, and energy-dispersive spectroscopy. The precipitates gained from the V(II)electrolyte at5 C and the V(V) electrolyte at 40 C have different physicochemical properties. Theinfluence of MSA on the electrochemical property is examined by cyclic voltammetry, linear polarization,and electrochemical impedance spectroscopy. According to the electrochemical analysis, MSA enhancesthe diffusion of the V(III) and V(IV) ions and the redox reaction rate of the V ions. Additionally, nuclearmagnetic resonance analysis is performed to understand the positive effect of MSA on the electrolyte. AVRFB full cell employing the electrolyte with MSA shows enhanced energy efficiency as well as highenergy density by improving electrolyte utilization.

Effect of Individual and District-level Socioeconomic Disparities on Cognitive Decline in Community-dwelling Elderly in Seoul

김건하,이혜아,박혜숙,이동영,조인호,최성혜,최경규,정지향 대한의학회 2017 Journal of Korean medical science Vol.32 No.9

This study was to investigate the effects of individual and district-level socioeconomic status (SES) on the development of cognitive impairment among the elderly. A 3-year retrospective observational analysis (2010–2013) was conducted which included 136,217 community-dwelling healthy elderly who participated in the Seoul Dementia Management Project. Cognitive impairment was defined as 1.5 standard deviations below the norms on the Mini-mental status examination. In the individual lower SES group, the cumulative incidence rate (CIR) of cognitive impairment was 8.7% (95% confidence interval [CI], 8.64–8.70), whereas the CIR in the individual higher SES group was 4.1% (95% CI, 4.08–4.10). The CIR for lower district-level SES was 4.7% (95% CI, 4.52–4.86), while that in the higher district-level SES was 4.3% (95% CI, 4.06–4.44). There were no additive or synergistic effects between individual and district-level SES. From this study, the individual SES contributed 1.9 times greater to the development of cognitive impairment than the district-level SES, which suggests that individual SES disparities could be considered as one of the important factors in public health related to cognitive impairment in the elderly.

콩고산 코발트 정광으로부터 제조한 매트의 고온고압침출

김건하,강가희,김수경,손정수,권경중,Kim, Gunha,Kang, Ga-hee,Kim, Sookyung,Sohn, Jeongsoo,Kwon, Kyungjung 한국자원리싸이클링학회 2015 자원리싸이클링 Vol.24 No.4

Cobalt is abundant only in some countries including Democratic Republic of the Congo. It would be necessary to secure overseas Co ores and Co extraction technology. Two kinds of matte varying the sulfur content were manufactured by smelting reduction of Co concentrate containing ~8 wt% Co, ~19 wt% Cu, and ~3 wt% Fe. The amount of Co, Cu and Fe was concentrated to 19~21 wt%, 39~41 wt%, and 7~9 wt% respectively in the resulting matte. High-pressure leaching of matte was performed in an autoclave with considering the effect of oxidizing agent, $H_2SO_4$ concentration as a lixiviant, and the amount of sulfur added to the matte. An oxidizing agent (oxygen) is necessary to improve Co leaching efficiency enabling usage of a dilute $H_2SO_4$ leaching agent. An increase in $H_2SO_4$ concentration prevents selective leaching of Co, and the sulfur content in matte has a minor influence on the Co leaching efficiency.

Role of Sand Capping in Phosphorus Release from Sediment

김건하,정우혁 대한토목학회 2010 KSCE JOURNAL OF CIVIL ENGINEERING Vol.14 No.6

Sand is the simplest capping material proposed to date to contain phosphorus in sediment in situ. This research was carried out to understand the role of sand capping in the speciation and release of phosphorus from sediment. Clean sand was laid on sediment sampled at a eutrophicated lake in one dimensional columns with different capping thicknesses. It could be understood from the experiments that sand capping with a thickness of less than 50 mm reduced the phosphorus concentration by over 85% and was effective in reducing the amount of phosphorus released from the sediment. Thicker sand capping reduces the amount of phosphorus released from the sediment to a greater extent. Since sand capping retards the release of phosphorus from the sediment, a higher fraction of non-apatite P (NA-P) was able to be converted into the less soluble Apatite-P (AP).

Effects of Non-Point Source Pollution on the Concentration of Pathogen Indicator Organisms in the Geum River Basin, Republic of Korea

김건하,Joong Hyun Yur 대한토목학회 2004 KSCE JOURNAL OF CIVIL ENGINEERING Vol.8 No.2

The pathogen indicator organism means pathogen associated non-pathogenic microorganisms for easier identification of the contamination. The pathogen indicator organisms can be used for estimating the impacts of non-point source pollution as their concentration is flow rate dependent. This study aims to determine the concentration of the pathogen indicator organisms in the Geum River basin and to understand the impacts of the non point source pollution on the water quality. In this study, total coliform, fecal coliform, and Escherichia coli concentrations were monitored at eight sites in the Geum River Basin. Total coliform concentration showed a high correlation with the flow rate, and a tendency of higher concentration for more agricultural land use in a monitored area. From the analysis of the relationship between flow rates and contaminant loads or concentration, two curves explained the relationships for the low flow and high flow conditions, respectively. Load duration curves were developed to estimate the impact of non-point source pollution on the water quality. From the load duration curve analysis, it can be understood that the water qualities of the Geum River are affected by non-point pollution significantly compare to the magnitude of point source pollution.

좌측 방사관 경색에 의해 발생한 자동-수의적 조절 해리를 보이는 하부 뇌신경마비와 조음불능증: Foix-Chavany-Marie증후군

김건하,윤영신,김용재,김정은,박기덕,최경규,정지향 대한신경과학회 2008 대한신경과학회지 Vol.26 No.4

Foix-Chavany-Marie Syndrome (FCMS) is characterized by anarthria and bilateral facio-pharyngo-glosso-masticatory paralysis with an automatic-voluntary dissociation, which usually develops in bilateral opercular lesions. We present a case of FCMS caused by unilateral subcortical lesion. A 54-year-old man was admitted due to acute right hemiparesis with anarthria. He had voluntary facial paresis but automatic-involuntary facial movements were preserved. MRI showed an acute left corona radiata infarction and PET revealed decreased glucose metabolism in left basal ganglia and fronto-parietal lobe.