Mechanism and process for the extraction of lithium from the high magnesium brine with N,N-bis(2-ethylhexyl)-2-methoxyacetamide in kerosene and FeCl3

Lianmin Ji,Licheng Zhang,Dong Shi,Xiaowu Peng,Jinfeng Li,Yuze zhang,Taoshan Xu,Lijuan Liao 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.113 No.-

The degradation of TBP has become a stumbling block to the industrial continuous production of lithiumchloride extraction from brines with high Mg/Li ratio by solvent extraction. To develop a more stable andmore efficient extraction system, a novel amide system, containing newly synthesized extractant N,N-bis(2-ethylhexyl)-2-methoxyacetamide (NBEHMOA), FeCl3 6H2O and sulfonated kerosene, was proposed inthis work. Compared with TBP and N523, NBEHMOA extracted Li+ and H+ in the sequence of TBP ˃NBEHMOA ˃ N523 and N523 ˃ TBP ˃ NBEHMOA respectively. The solution containing 5.5 mol/L LiCland 0.5 mol/L HCl was used as the eluent in the scrubbing process. A Li+ extraction efficiency of 96.7%and 22.31 g/L Li+ in the stripping solution were achieved by the whole process with counter-currenttwelve stages. The extraction mechanism investigated via FT-IR spectroscopy illustrated that the metalions Fe3+ and Li+ were mainly coordinated by the carbonyl C = O in NBEHMOA. This novel amide systemcan successfully achieve the cascade extraction effect for lithium, Li/Mg separation and avoid the generationof phase interface objects through counter-current extraction of lithium from brine at a lower acidity. This work provided a novel extraction system to recover lithium from the higher magnesium/lithiumratio brines.

Preparation of layered double hydroxides intercalated by tartaric acid anion and its application in boron adsorption

Lianmin Ji,Liang Cai,Yuze zhang,Xiaowu Peng,Dong Shi,Lijuan Li 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.123 No.-

Based on the exchangeability of anions between the layers of magnesium-based LDHs, LDHs intercalatedby tartaric acid anion (TA-LDH) was prepared by co-precipitation method to adsorb boron, and confirmedby XRD and FT-IR that TA had successfully entered the interlayer of LDH. The adsorption kinetics showedthat the adsorption efficiency of B was mainly controlled by the chemisorption mechanism. The thermodynamicsrevealed that the relationship between the equilibrium concentration of B in solution and theadsorption capacity of TA-LDH for B was consistent with the Freundlich model. Cl or Li+ in solution hadlittle effect on the adsorption of B by TA-LDH, while SO4 2 had a great effect on that compared with NO3-LDH. Boron adsorption was accomplished through the interaction between the hydroxyl of TA anion inthe interlayer and that of B(OH)3 and B(OH)4. The elution efficiency of TA-LDH was greater than 70% withammonium chloride used as the eluent. While TA-LDH still maintained a good adsorption capacity after 5cycles, and the solubility loss efficiencies of Mg2+ in a single adsorption and elution were 1.5% and 5.4%,respectively. Our study can provide a new idea and method for the development and utilization of magnesiumresources.

Cathode Materials LaNi1−xCuxO3 for Low Temperature Solid Oxide Fuel Cells

Juncai Sun,Chengli Wang,Song Li,Shijun Ji 한국세라믹학회 2008 한국세라믹학회지 Vol.45 No.12

New cathode materials LaNi1−xCuxO3 (typically LaNi0.8Cu0.2O3) were synthesized using a co-precipitation method. The structure and morphology of the powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The composite material [Ce0.8Sm0.2O2-ä(SDC) and carbonate (Na2CO3,Li2CO3)], NiO and LaNi1−xCuxO3 were used as the electrolyte, anode and cathode, respectively. The electrochemical performance of La-Ni-Cu-O perovskite oxide at low temperatures (400~550oC) was studied. The results showed that LaNi0.8Cu0.2O3 precursor powder prepared through a co-precipitation method and calcined at 860oC for 2 h formed uniform grains with diameters in the range of 400~500 nm. The maximum power density and the short circuit current density of the single cell unit at 550oC were found to be 390 mW/cm2 and 968 mA/cm2, respectively. New cathode materials LaNi1−xCuxO3 (typically LaNi0.8Cu0.2O3) were synthesized using a co-precipitation method. The structure and morphology of the powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The composite material [Ce0.8Sm0.2O2-ä(SDC) and carbonate (Na2CO3,Li2CO3)], NiO and LaNi1−xCuxO3 were used as the electrolyte, anode and cathode, respectively. The electrochemical performance of La-Ni-Cu-O perovskite oxide at low temperatures (400~550oC) was studied. The results showed that LaNi0.8Cu0.2O3 precursor powder prepared through a co-precipitation method and calcined at 860oC for 2 h formed uniform grains with diameters in the range of 400~500 nm. The maximum power density and the short circuit current density of the single cell unit at 550oC were found to be 390 mW/cm2 and 968 mA/cm2, respectively.

敎養 中國語 新探

李吉子 명지대학교 인문과학연구소 2000 인문과학연구논총 Vol.22 No.-

여성에서 왜 우울증이 많은가?

송지영,이광철 경희대학교 2002 慶熙醫學 Vol.18 No.3-4

라미부딘 내성 만성 B형 간염 환자에서의 아데포비어의 치료 효과

이지숙,장리라,이상욱,한병훈,윤병철 고신대학교의과대학 2008 고신대학교 의과대학 학술지 Vol.23 No.2

Backgrounds/Aims : Adefovir dipivoxil(ADV) has been shown to be effective against lamivudine resistant strain of hepatitis B virus. But continuation of lamivudine therapy or switching to Adefovir dipivoxil in patients with viral breakthrough after long term lamivudine therapy are controversial. To find efficacy of adefovir dipivoxil, we retrospectively assessed clinical course after lamivudine resistance in patients who changed adefovir dipivoxil and continued lamivudine therapy. Methods : 58 patients with lamivudine resistant HBV mutants after at least 6 months of lamivudine treatment were included in this study. 24 of the 58 patients were treated with ADV and rest of them were continued the lamivudine therapy after lamivudine resistance. The continuous lamivudine treatment group (n=34) was divided into two groups according to ALT count (ALT≧40, n=19 vs ALT<40, n=16) The clinical course and the biochemical and virological response of the switching adefovir group were compared with those of continuing lamivudine group. HBV genotypes and YMDD mutation site was anaylzed by TRUGENE HBV Genotyping. Results : At twelve months, the levels of median serum HBV DNA and ALT was decreased and albumin was improved significantly(P<0.01) in adefovir switching group compared with lamivudine sustained group, especially ALT was elevated more than 40. There is no significant differences between adefovir switching group and lamivudine sustained group (ALT<40, n=15). This study showed that adefovir dipivoxil reduces HBV replication and improves not only biochemical markers of disease activity, but also liver function. HBV genotypes of 58 patients were all C and rtM204I/V mutant was the most common. Conclusion : This study provides an evidence that adefovir dipivoxil can be effective in the treatment of lamivudine-resistant HBV mutants, especially ALT elevated.

웹 서버 보안 취약점 점검 방안 연구 동향

나현혜,이루리,이지윤,윤지혜,김윤정 서울여자대학교 컴퓨터과학연구소 2011 정보기술논문지 Vol.9 No.-

본 논문에서는 웹서버 보안 취약점 점검 방안에 대한 연구 동향을 조사하고 분석한다. 우선, 한국인터넷진흥원 인터넷침해대응센타에서 발표한 웹 취약점 공격동향에 대하여 살펴본다. 다음으로, 취약점 점검 항목에는 어떠한 것들이 있는지에 대해 소개하고, 예상 공격 시나리오와 그 공격들을 방어하는 방법에 대해 설명한다. 이들 점건 항목들은 주로 OWASO(Open Web Application Security Project)를 기반으로 한다. 그리고, 현재 이용되고 있는 웹 서버 보안 취약점 점건 도구들에 대하여 살펴본다. 본 연구 결과를 이용하여 웹서버를 안전하게 관리함으로써, 안전한 컴퓨터 및 네트워크 환경에 기여하고자 한다.

바터팽대부 선암의 β-catenin 표현

현연화,구지혜,이강,박선미,성노현 충북대학교 의과대학 충북대학교 의학연구소 2010 忠北醫大學術誌 Vol.20 No.1

Purpose : Carcinomas of the ampulla of Vater have either intestinal or pancreatobiliary type differentiation. The molecular pathogenesis of both histologic types of ampullary carcinoma are not yet well characterized. The role of β-catenin pathway is important in colorectal carcinogenesis and β-catenin protein expression is dysregulated in the early stage of the adenoma-carcinoma sequence. The aim of this study is to investigate the differences between dysregulated β-catenin expression in the carcinogenesis of two histologic types of carcinoma of the ampulla of Vater. Materials and Methods : We examined 24 cases of resected carcinoma of the ampulla of Vater. Serial sections of all carcinoma specimens were stained with antibodies to cytokeratins (CK7, CK20) and β-catenin. Normal expression of β-catenin was defined as exclusive membranous staining. Dysregulated expression of β-catenin was defined as cytoplasmic staining in more than 50% of tumor cells and/or nuclear staining. Results : Ten carcinomas (42%) were immunohistochemically intestinal type (CK7-, CK20+) and eleven carcinomas (46%) were pancreatobiliary type (CK+, CK20-). Three carcinomas were immunohistochmically other types (CK7+, CK20+ or CK7-, CK20-). Abnormal β-catenin was accumulated in nine cases (90%) of intestinal type. Among them, nuclear staining was noted in two cases with moderately and poorly differentiated histology respectively. In pancreatobiliary type, only one case (9%) with poorly differentiated histology showed abnormal β-catenin expression in tumor nuclei. Conclusion : Dysregulation of β-catenin expression may play critical role in the carcinogenesis of intestinal type, but not of pancreatobiliary type. Abnormal accumulation of β-catenin in tumor nuclei may be related to poorly differentiated histology in both types of ampullary carcinoma. 연구 목적: 바터팽대부에서 발생하는 선암의 대부분은 조직학적으로 장형과 췌담형으로 구성된다. 두 병변의 발암기전은 뚜렷하게 밝혀진 바는 없으나, 췌담형 선암은 췌담도 선암의 발암기전과 유사하고, 장형 선암은 장 선암의 발암기전과 유사하다고 추측한다. 대부분의 장 선암에서는 암 발생 초기에 세포 안에 β-catenin의 축적이 발생하며, 축적된 β-catenin이 전암 세포 또는 암 세포의 증식을 유발하는 중요한 역할을 한다. 그러나 대부분의 췌담도 선암의 발생 과정에서는 β-catenin 축적에 의한 세포 증식은 중요한 역할을 하지 않는다. 바터팽대부에서 발생하는 장형 선암과 췌담형 선암의 발암 과정의 유사점 또는 차이점을 규명하기 위하여, 장 선암의 발암 과정에서는 중요한 역할을 하지만 췌담도의 선암의 발암 과정에는 역할이 중요하지 않은 β-catenin의 축적으 면역조직화학 방법으로 비교하였다. 재료 및 방법: 충북대학교병원에서 외과적 수술로 절제한 바터팽대부에서 발생한 선암 24 예의 조직 slide를 현미경으로 관찰하고, 각 증례의 병변을 대표하는 조직의 paraffin 포매 block 한 개를 선택하여 박편을 제작하였다. 장형 선암과 췌담형 선암을 면역조직화학 방법으로 구분하기 위하여 각 박편에 통상적인 avidin-biotin immunoperoxidase 방법으로 cytokeratin 7과 cytokeratin 20 면역 염색을 하였으며, 발암기전의 차리를 알기 위하여 β-catenin 면역 염색을 하였다. β-catenin의 축적은 종양 세포의 50% 이상에서 세포질에 뚜렷하게 염색된 경우와 종양 세포의 핵에 염색된 경우를 양성으로 하였다. 결과: 10 예는 cytokeratin 7에 음성. cytokeratin 20에 양성이어서 장형 선암으로 분류하였다. 11 예는 cytokeratin 7에 양성. cytokeratin 20에 음성이어서 췌담형 선암으로 분류하였다. 3 예는 cytokeratin 7과 cytokeratin 20에 모두 양성 또는 모두 음성이엇 연구에서 제외하였다. 장형 선암은 9 예(90%)에서 β-catenin의 축적이 나타났다. 종양 세포 핵의 β-catenin 축적은 중등도 분화 암 3 예 중에서 1 예. 저등도 분화 암 1 예 중 1 예에서 관찰되었다. 고등도 분화 암에 동반된 선종 2 예에서도 종양 세포의 세포질에 β-catenin의 축적이 관찰되었다. 췌담형 선암은 11 예 중에서 1 예(9%)에서 β-catenin의 축적이 나타났으며 나머지 10 예는 세포막에만 염색되었다. β-catenin의 축적은 저등도 분화 암 1 예 중에서 1 예에 나타났으며 세포 핵에서 β-catenin의 축적이 나타났다. 결론: 바터팽대부에서 발생하는 장형 선종과 선암의 발암 과정에는 β-catenin의 축적이 중요한 역할을 하며, 장형 선암의 발암 과정은 장의 선종-선암 과정과 유사함을 시사하였다. 바터팽대부에서 발생하는 대부분의 췌담형 선암 세포에서는 β-catenin의 축적이 발생하지 않았으므로 췌담형 선암의 발암기전은 장형 선암의 발암기전과 다름을 시사하였다. 그러나 β-catenin의 종양 세포 핵 축적은 바터팽대부에서 발생하는 장형과 췌담형 선암의 악성화와 관계가 있었다.

Scalable graphene composite membranes for enhanced ion selectivity

Li, Siying,Lee, Jung-Hun,Hu, Qicheng,Oh, Tae-Sik,Yoo, Ji-Beom Elsevier 2018 Journal of membrane science Vol.564 No.-

<P><B>Abstract</B></P> <P>Unintended defects are a significant problem for mass production of graphene membranes. Herein, we report a method to fabricate scalable CVD graphene polymer membranes through the formation of a polysulfone (PSf) supporting layer, which is capable of duplicating the Cu morphology. Unintended defects were limited by minimizing defects associated with graphene wrinkles and eliminating polymer residues used in the transfer process. Consequently, the KCl leakage by diffusion of raw graphene membranes fabricated with this method was only ~ 0.5% that of the supporting membrane; there was also no water flux under a pressure of 20 bar. Excellent ion selectivity was achieved by controlling the duration of H<SUB>2</SUB> plasma treatment. The selectivity of KCl over NaCl was 2.61, the selectivity of KCl over MgCl<SUB>2</SUB> was 15.62, and the selectivity of NaCl over MgCl<SUB>2</SUB> was 5.98.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Polysulfone formed in Ethanol coagulation bath performed better permeability comparing to that formed in water coagulation bath. </LI> <LI> Cu foil morphology was duplicated by liquid phase PSf solution to minimize additional graphene wrinkles and unintended defects. </LI> <LI> ~ 0.5% KCl leakage by diffusion of raw graphene membranes that of the supporting membrane. </LI> <LI> Artificial graphene defects were enlarged and controlled with hydrogen plasma. </LI> <LI> The membrane exhibited an excellent selectivity among KCl, NaCl, MgCl<SUB>2</SUB> salts. </LI> </UL> </P>

Visible light assisted NO₂ sensing at room temperature by CdS nanoflake array

Li, Hua-Yao,Yoon, Ji-Won,Lee, Chul-Soon,Lim, Kyeorei,Yoon, Ji-Wook,Lee, Jong-Heun Elsevier 2018 Sensors and actuators. B, Chemical Vol.255 No.3

<P><B>Abstract</B></P> <P>A Highly ordered CdS nanoflake array was fabricated by CVD, and its gas sensing characteristics were investigated. The sensor exhibited high response (resistance ratio) of 89% to 5 part per million (ppm) nitrogen dioxide (NO<SUB>2</SUB>) under green LED illumination (wavelength 500–540nm, irradiance 21W/m<SUP>2</SUP>) with excellent selectivity and little interference by humidity. Moreover, the sensor showed promising potential for operating under fluorescent lamp and natural solar light, which can be used for medical diagnosis and indoor/outdoor environment monitoring. This performance is attributed to the low band gap energy (2.4eV) of CdS and the unique morphology of nanoflake array which can enhance both the light absorption and conductivity.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CdS NO<SUB>2</SUB> gas sensor operated under both fluorescent lamp and natural solar light. </LI> <LI> 2D nanoflake array CdS films for enhanced light absorption and charge transport. </LI> <LI> CdS gas sensor with high response to NO<SUB>2</SUB>, little influence by humidity. </LI> <LI> Elucidation of visible-light-enhanced NO<SUB>2</SUB> sensing mechanism. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>