• Title/Summary/Keyword: complete collapse

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Embedding Cobalt Into ZIF-67 to Obtain Cobalt-Nanoporous Carbon Composites as Electrode Materials for Lithium ion Battery

  • Zheng, Guoxu;Yin, Jinghua;Guo, Ziqiang;Tian, Shiyi;Yang, Xu
    • Journal of Electrochemical Science and Technology
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    • v.12 no.4
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    • pp.458-464
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    • 2021
  • Lithium ion batteries (LIBs) is a kind of rechargeable secondary battery, developed from lithium battery, lithium ions move between the positive and negative electrodes to realize the charging and discharging of external circuits. Zeolitic imidazolate frameworks (ZIFs) are porous crystalline materials in which organic imidazole esters are cross-linked to transition metals to form a framework structure. In this article, ZIF-67 is used as a sacrificial template to prepare nano porous carbon (NPC) coated cobalt nanoparticles. The final product Co/NPC composites with complete structure, regular morphology and uniform size were obtained by this method. The conductive network of cobalt and nitrogen doped carbon can shorten the lithium ion transport path and present high conductivity. In addition, amorphous carbon has more pores that can be fully in contact with the electrolyte during charging and discharging. At the same time, it also reduces the volume expansion during the cycle and slows down the rate of capacity attenuation caused by structure collapse. Co/NPC composites first discharge specific capacity up to 3115 mA h/g, under the current density of 200 mA/g, circular 200 reversible capacity as high as 751.1 mA h/g, and the excellent rate and resistance performance. The experimental results show that the Co/NPC composite material improves the electrical conductivity and electrochemical properties of the electrode. The cobalt based ZIF-67 as the precursor has opened the way for the design of highly performance electrodes for energy storage and electrochemical catalysis.

Risk Assessment of Cut Slope by Gravity Field Interpretation and Modelling (비탈면 위험도 평가를 위한 중력장 해석 및 모델링)

  • Choi, Sungchan;Kim, Sung-Wook;Choi, Eun-Kyoung;Lee, Yeong-Jae;Jang, Hyun-Ick
    • The Journal of Engineering Geology
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    • v.31 no.4
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    • pp.533-540
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    • 2021
  • Gravity field analysis and density modeling were performed to evaluate the internal state of the rock mass, which is the cause of cut slope collapse. The shape of the weathered zone and the depth of basement could be confirmed from the complete Bouguer anomaly and density model. The basement depth at the center of the cut slope calculated using the Euler deconvolution inverse method is 30 m, which is about 10 m deeper than the surrounding area. In addition, the depth of basement and the thickness of the weathered zone are similar to the boundary between low resistivity and high resistivity in dipole-dipole survey. From the study results, gravity field analysis and density modeling recognizes the internal state of the rock slope and can be used for slope safety analysis, and is particularly suitable as a method to determine the shape of weathered zones in interpreting the safety of cut slopes

Efficacy of UN's Sanctions on North Korea's Nuclear and North Korea's Regime Survival Strategy (유엔의 북핵 대북제재조치의 실효성과 북한의 체제생존전략)

  • KIM, JOO-SAM
    • Korea and Global Affairs
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    • v.2 no.1
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    • pp.69-92
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    • 2018
  • North Korea conducted a total of six nuclear tests from the 1st test of 2006 to September, 2017. North Korea developed an armed forces security strategy at the level of regime protection and defense to respond to U.S. hostile policy. However, it is certain that strategic goals of North Korea's nuclear test were to overcome a crisis in North Korea's regime through US-North Korea negotiation and complete nuclear armed forces for socialist unification on the Korean Peninsula. North Korea's continuous nuclear test is a direct factor in threatening peace on the Korean Peninsula and an indirect factor in security dynamics of Northeast Asia. The U.N. Security Council has enforced sanctions against North Korea through six resolutions against North Korea's reckless nuclear test for the past 10 years. However, Kim Jong-Un's regime is in a position to stick to simultaneous pursuit of nuclear and economic development in spite of anti-North sanction of international society including U.N. and U.S.A. It is understood that North Korea was stimulated to conduct intense nuclear test as U.N. and U.S.A's anti-North sanction was not effective on North Korea. Full-scale and local wars are expected as military options, one of anti-North sanctions of the Trump administration. The Trump administration has attempted diplomatic pressure strategy as a secondary boycott unlike previous administrations. Nevertheless, North Korea has stood against U.N. and U.S.A's anti-North sanction with brinkmanship tactics, announcing full-scale military confrontation against U.S. It is judged that North Korea will pursue simultaneous nuclear weapons and economic development in terms of regime survival. North Korea will have less strategic choices in that its regime may collapse because of realistic national strategy between U.S.A. and China.

An Outlook of the Oriental and Western Medical Diagnosis and Treatment on Large Bowel Cancer (대장암(大腸癌)의 동서의(東西醫) 결합(結合) 진치근황(診治近況))

  • Kim, Byeong-Ju;Moon, Goo
    • THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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    • v.5 no.1
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    • pp.1-17
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    • 1999
  • Large bowel cancer shows the 4-5th frequency in cancers that occurs in Korea. The western medicine cures the Large bowel cancer by radiation, surgery and chemotherapy. While, Oriental medicine cures the Large bowel cancer by Herb-drugs, acupuncture, moxa and et al. With just one way of treating Large bowel cancer can't be effective remedy. Because each medicine has a strength and weakness, it is effective treatment when two medicine combines and supplement each other. We got the following result about a trend of oriental and western combination treatment for Large bowel cancer through studding records. 1. In Large bowel cancer, colon cancer is referred hematochezia(腸風下血), rectal cancer is refereed enterotoxin(腸毒), and anal cancer is accumulation of pathogens in yin(結陰). 2. The western medicine treats Large bowel cancer patient with surgery first. They need on assembly treatment such as chemical, radiation and immune treatment. In oriental medicine, they treats Large bowel cancer patients with differentiation of symptom and signs and treatment(辨證施治) for example, insufficiency of spleen and stomach(脾胃虛弱), collapse of the spleen-ql(脾氣下陷), stagnation of blood stasis and toxic agent(瘀毒內結), reinforcing both qi and blood(脾血下陷), stagnation of damp-phlegm(痰濕凝結) and cure for them by acupuncture and moxa too. 3. In combination with oriental and western medical treatment princple of Large bowel cancer by each stage is as follows. First stage is cured with radical surgery and herb-drugs without chemotherapy. The intermediate and terminal stage patients is used radiation before surgery, or after palliative surgery cour with chemotherapy, radiation and Herb-drugs. In terminal stage patients, unable for surgery, is used combination between chemotherapy, palliative radiation and Herb-drugs. 4. After radiation surgery, the terminal stage patients who have extensively lymph node metastasis or local contraindication is able to undergo combination of Herb-durgs and chemotherapy. 5. The cure-effect with oriental and western medicine combination treatment was better than that just with oriental or western medical treatment. 6. The merits of oriental and western medicine combination treatment lengthen one's life and diminish the bad effect of chemotherapy and complete radiation treatment, prevent from relapsing, maintain the balance in their environment of body and improve immunity.

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Hypoadrenocortical Crisis-like Transient Hyponatremia and Hyperkalemia in a Near-Term Pregnant Dog (분만 직전의 개에서 급성 부신겉질저하증과 유사한 일과성 저나트륨혈증 및 고칼륨혈증 일례)

  • Kang Ji-houn;Kim Min-jun;Cho Min-haeng;Chang Dong-woo;Kang Hyun-gu;Kim Ill-hwa;Na Ki-jeong;Yang Mhan-pyo
    • Journal of Veterinary Clinics
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    • v.22 no.4
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    • pp.450-452
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    • 2005
  • A 3-year-old, 43kg, pregnant Great Pyrenese was examined for clinical signs of acute weakness and anorexia for 4 days. The dog was in lateral recumbency at referral. The rectal temperature was within reference range, and the respiratory and heart rates were 36 breaths/min and 58 beats/min, respectively. The abdomen was distended, and several puppies were palpated. The mean fetal head diameter was 2.8cm in the ultrasonographic examination. The initial complete blood count and serum biochemical examinations revealed mild dehydration, mud hyperglycemia, hypochloremia, hyperkalemia, hyponatremia, and low sodium-potassium ratio. Serum BUN and total cholesterol values were slightly high. Hypoadrenocortical crisis was suspected on the basis of signs of acute collapse, hyponatremia and hyperkalemia. Adrenal gland function was evaluated by an ACTH stimulation test. The baseline cortisol concentration was $18.6{\mu}g/dl$ and the concentration at 1 hour after administration of tetracosactrin (ACTH, Synacthen) was $8{\mu}g/dl$. The dog was treated for the correction of assumed hypoadrenocortical crisis and substantial hyperkalemia. In addition to rapid infusion with saline solution, other medications administered intravenously included sodium bicarbonate and cimetidine hydrochloride. The dog was monitored with repeated serum electrolyte examination. After clinical stabilization, cesarean section was performed. All of 13 puppies were delivered, and the dog recovered from anesthesia without complications. The values of postpartum blood tests returned to normal or within reference range. The dog remained healthily.

A Case of Long-Term Management of Insulinoma in a Maltese Dog (말티즈 개에서 인슐린종의 장기간 관리 증례)

  • Park, So-Young;Kang, Byeong-Teck;Kang, Ji-Houn;Chang, Dongwoo;Yang, Mhan-Pyo
    • Journal of Veterinary Clinics
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    • v.30 no.5
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    • pp.363-365
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    • 2013
  • A 15-year-old, spayed female Maltese dog weighing 2.80 kg was referred with seizure of unknown origin. At presentation, serum biochemistry showed marked hypoglycemia (46 mg/dL; reference interval [RI], 65-118 mg/dL). There were, however, no abnormalities on electrolytes, complete blood counts, urinalysis, survey radiographs, and abdominal ultrasonography. In the adrenocorticotropic hormone (ACTH) stimulation test, pre-ACTH and post-ACTH cortisol concentrations were within normal reference ranges. Serum insulin level was normal and fructosamine level was slightly lower than reference ranges. The clinical signs, including seizure and collapse caused by hypoglycemia, were gradually resolved with oral administration of prednisolone (PDS) twice daily. Forty five weeks later, serum biochemistry revealed hypoglycemia with markedly increased insulin level. On abdominal ultrasonography, increased heterogenous echogenecity with hypoechoic lesion was found within pancreatic parenchyma. Based on these findings, the dog was presumptively diagnosed to insulinoma. Hypoglycemic seizure was resolved with higher dose of PDS (1 mg/kg, q12h). At 688 days after first presentation, the patient was still alive without recurrence of hypoglycemic seizure. This case describes long-term management with PDS monotherapy in a Maltese dog with insulinoma.

Correlation Between Knowledge and Educational Needs Related to Recurrent in Coronary Artery bypass graft patients (관상동맥 우회술환자의 수술 후 재발 관련 지식과 교육요구도와의 상관관계)

  • 김희승;박민정
    • Journal of Korean Academy of Nursing
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    • v.30 no.3
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    • pp.549-559
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    • 2000
  • The purpose of this study was to investigate the correlation between the knowledge and educational needs related to recurrent in coronary artery bypass graft patients as a basis to provide an individual nursing education for the population. The subjects consisted of 110 patients who had coronary artery bypass graft(CABG) at Asan Medical Center in Seoul and Sechong hospital in Buchon. Data was obtained from a knowledge questionnaire and a learning needs questionnaire between November 1998 and February 1999. Data were analyzed using SAS program for Wilcoxon rank sum test and Spearman correlation coefficient. The results were as follows : 1. With regard to the 18 items to measure knowledge, the mean (median) of items 'don't know' was 4.9(4) items. The mean (median) of items answered wrong was 3.2(3) items. The number of items answered 'don't know' tend to show higher in those who had less education, blue color jobs and myocardiac infarction history than in their counter parts. There were higher frequency of items answered 'don't know' in those who had no hypertension 2. With regard to the level of knowledge by questionnaire about CABG, The most "I dont know" (59.1%) highly response was 'He has to be treated with anticoagulant drug to prevent revasculized vessel from obstructing.' The seond highest response (56.4%) was 'If you were hypotensive, the coronary attack would collapse. 'During the hospitalized day, the patient has complete bedrest.' The highest error probability was cholesterol has not to intake.', 'After surgery, the sexual life is need controlled for 1 year. 3. The mean of educational needs was 3.38. With regard to the level of learning needs by sentence about CABG, 'Food that benefit heart disease', 'Recurrence possibility of heart disease', 'Management method of operation site', 'Risk symptom that visit hospital or report immediately' were higher than other sentenses. With regard to the level of learning needs by factor 'food(5 items)', 'disease(9 items)' and 'exercise(3 items)' showed the highest than other factors. The educational needs by patients characteristics tend to show higher in males, under the age of 49, middle or high school degree, previous experience of admission with coronary artery disease, history of myocardial infarction, expierience of PTCA, history of cerebro-vascular accident, previous expierience of smoking than in their counter parts. 4. The number of items answered 'don't know', wrong and correct weren't correlated with the level educational needs. As the results, the number of items answered 'don't know' tend to show higher in those who had less educated, blue color jobs and myocardiac infarction history than in their counter parts. There were higher frequency of items answered 'don't know' in those who had no hypertension .There were higher frequency of items answered 'don't know' on anti-thrombolitic theraphy, hypotension and pain relief. Also there were higher frequency of items answered wrong on bed rest period, cholesterol intake, and sexual life. Educational needs were higher in young age group, had previous experience of procesure and history of other disease. And when we educate CABG patients, education for diet, recurrence possibility of disease, management methods of operation site and risk symptom should be emphasized.

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The Clay Mineralogy of some Low Productive Paddy Soils In Kyonggi-Do (경기도(京畿道) 저위생산답(低位生産畓)의 점토광물(粘土鑛物)에 관(關)한 연구(硏究))

  • Shim, Sang Chil;Kim, Tai Soon;Lee, Hyung Koo;Song, Ki Joon;Valencia, I.G.
    • Korean Journal of Soil Science and Fertilizer
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    • v.7 no.3
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    • pp.127-135
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    • 1974
  • The samples were taken from the following localities previously classified as "Akiochi" area: Yangpyung, Puchun, and Pyungtaik, all of Kyonggi-do province. Five soil profiles were described in the field, and taken to the laboratory for physical and chemical analysis and mineralogical analysis by X-ray diffraction. The predominant clay minerals consist mainly of illite, vermiculite, chlorites and intergrade with vermiculite, and kaolinite. Illite or mica was found present in all samples and in all horizons. This was identified by the 9.83 to $10{\AA}$ (0.01) and $3.32{\AA}$ (003) basal reflections, Interhorizontal variations in mineral content and crystallinity are illustrated in their respective Xray diffractogram. Comparing the peak intensity, of the $14{\AA}$, $10{\AA}$ and $7{\AA}$ indicated the degree of weathering from the surface to the lower horizons. In general, the weathering of illite on the surface produced less pronounced $10{\AA}$ and $14{\AA}$ peak as compared to the lower horizons. The same may be said with kaolinite. On K-saturation, the $14{\AA}$ peak broadening on the low angle side was observed. This is interpreted to be due to chlorization. Heat treament from $100^{\circ}C$, $200^{\circ}C$, $400^{\circ}C$, $600^{\circ}C$, and $800^{\circ}C$. caused significant changes in the different diffractograms. Heating caused collasped of the $14{\AA}$ to $10{\AA}$ and the appearance of scattered peaks between $10-14{\AA}$. This is interpreted to the presence of vermiculite chlorite intergradient. The complete collapse of the $14{\AA}$ at $800^{\circ}C$ to $10{\AA}$ with increased intensity was attributed to the preservce of vermiculite. The principal difference among the clay minerals in each horizon is the concomitant increase and decrease in intensity with depth of the $14{\AA}$, $10{\AA}$ and $7{\AA}$ diffraction spacings. Apparently the weathering of illite ($10{\AA}$) is resulting in the formation of vermiculite ($14{\AA}$) and the interstratified material being an intermediate stage and the beginning of the formation of vermiculite. Some broadening- in the 17 to $18{\AA}$ was observed in Puchun-1 Pyungtaik-1 and Pyungtaik-2 specially so in the lower horizon in the Ca or Mg-saturated sample. Heated treatment tend to shift this peak to $14{\AA}$ indicating the presence of regular layering of the interstratified complex. The high amount of extractable aluminum and iron coupled with low exchange capacity indicate that iron and aluminum plays an important role in the weathering of these soils and is responsible to the low exchange capacity, high acidity and high phosphate absorptive capacity. The results presented substantiated the weathering sequence of Jackson in that mica ${\rightarrow}$ vermiculite ${\rightarrow}$ chloritezed vermiculite ${\rightarrow}$ kaolinite.

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The Value of Preoperative MRI and Bone Scan in Percutaneous Vertebroplasty for Osteoporotic Vertebral Compression Fractures (골다공증성 척추체 압박골절에 대한 경피적 척추성형술시 자기공명영상과 골 주사 검사의 의의)

  • Kim, Se Hyuk;Lee, Wan Su;Seo, Eui Kyo;Shin, Yong Sam;Zhang, Ho Yeol;Jeon, Pyoung
    • Journal of Korean Neurosurgical Society
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    • v.30 no.7
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    • pp.907-915
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    • 2001
  • Objective : Percutaneous vertebroplasty is often complicated by the presence of multiple fractures or non-localizing pain in the patients with osteoporotic vertebral fractures. The purpose of this study is to estimate the value of preoperative radiologic studies in the localization of symptomatic vertebrae and to determine the factors which can influence on the clinical results. Materials and Methods : We retrospectively reviewed the clinical and radiologic data of 57 vertebrae in 30 patients underwent percutaneous vertebroplasty for osteoporotic vertebral compression fractures. Inclusion criteria was severe pain(McGill-Melzack score 3, 4 or 5) associated with the acute vertebral fractures and absence of spinal nerve root or cord compression sign. Acute symptomatic vertebral fracture was determined by the presence of signal change on MR images or increased uptake on whole body bone scan. Results : Pain improvement was obtained immediately in all patients and favorable result was sustained in 26 patients(86.7%) during the mean follow-up duration of 4.7 months(5 complete pain relief, 21 marked pain relief). Those who underwent vertebroplasty for all acute symptomatic vertebrae had significantly better clinical result than those who did not. Further vertebral collapse and eventual bursting fracture occurred in 1 vertebra which showed intradiskal leakage of bone cement and disruption of cortical endplate on postoperative CT scan. Conclusion : Preoperative MR imaging and whole body bone scan are very useful in determining the symptomatic vertebrae, especially in the patients with multiple osteoporotic vertebral fractures. To obtain favorable clinical result, the careful radiologic evaluation as well as clinical assessment is required. Control of PMMA volume seems to be the most critical point for avoiding complications.

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Experimental and analytical study of squat walls with alternative detailing

  • Leonardo M. Massone;Cristhofer N. Letelier;Cristobal F. Soto;Felipe A. Yanez;Fabian R. Rojas
    • Computers and Concrete
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    • v.33 no.5
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    • pp.497-507
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    • 2024
  • In squat reinforced concrete walls, the displacement capacity for lateral deformation is low and the ability to resist the axial load can quickly be lost, generating collapse. This work consists of testing two squat reinforced concrete walls. One of the specimens is built with conventional detailing of reinforced concrete walls, while the second specimen is built applying an alternative design, including stirrups along the diagonal of the wall to improve its ductility. This solution differs from the detailing of beams or coupling elements that suggest building elements equivalent to columns located diagonally in the element. The dimensions of both specimens correspond to a wall with a low aspect ratio (1:1), where the height and length of the specimen are 1.4 m, with a thickness of 120 mm. The alternative wall included stirrups placed diagonally covering approximately 25% of the diagonal strut of the wall with alternative detailing. The walls were tested under a constant axial load of 0.1f'cAg and a cyclic lateral displacement was applied in the upper part of the wall. The results indicate that the lateral strength is almost identical between both specimens. On the other hand, the lateral displacement capacity increased by 25% with the alternative detailing, but it was also able to maintain the 3 complete hysteretic cycles up to a drift of 2.5%, reaching longitudinal reinforcement fracture, while the base specimen only reached the first cycle of 2% with rapid degradation due to failure of the diagonal compression strut. The alternative design also allows 46% more energy dissipation than the conventional design. A model was used to capture the global response, correctly representing the observed behavior. A parametric study with the model, varying the reinforcement amount and aspect ratio, was performed, indicating that the effectiveness of the alternative detailing can double de drift capacity for the case with a low aspect ratio (1.1) and a large longitudinal steel amount (1% in the web, 5% in the boundary), which decreases with lower amounts of longitudinal reinforcement and with the increment of aspect ratio, indicating that the alternative detailing approach is reasonable for walls with an aspect ratio up to 2, especially if the amount of longitudinal reinforcement is high.