47,625 research outputs found
Production of Biologically Active Human Granulocyte Colony Stimulating Factor in the Milk of Transgenic Goat
No full textJung Ho Ko, Chul Sang Lee, Seung Won Jin, Sang Tae Shin, Ja Shin Koo, Kyung Kwang Lee, Ook Joong Yo
The Korean War and U.S. Public Opinion: June 1950 to January 1951
No full textSubmitted by Henry Roberson ([email protected]) on 2011-10-17T21:32:52Z
No. of bitstreams: 1
Jung, Soo-ho - Fall '10.pdf: 453627 bytes, checksum: 92be39242b141f78245717efeaac760a (MD5)Made available in DSpace on 2011-10-17T21:32:52Z (GMT). No. of bitstreams: 1
Jung, Soo-ho - Fall '10.pdf: 453627 bytes, checksum: 92be39242b141f78245717efeaac760a (MD5
Ho-Jung Shin
No full text학위논문(석사)--아주대학교 일반대학원 :의학과,2017. 2Purpose: Obesity is associated with morbidity following gastric cancer surgery, but whether obesity influences morbidity after laparoscopic gastrectomy (LG) remains controversial. The present study evaluated whether body mass index (BMI) and visceral fat area (VFA) predict postoperative complications.
Materials and Methods: A total of 217 consecutive patients who had undergone LG for gastric cancer between May 2003 and December 2005 were included in the present study. We divided the patients into two groups (‘before learning curve’ and ‘after learning curve’) based on the learning curve effect of the surgeon. Each of these groups was sub-classified according to BMI (<25 kg/m2 and ≥25 kg/m2) and VFA (<100 cm2 and ≥100 cm2). Surgical outcomes, including operative time, quantity of blood loss, and postoperative complications, were compared between BMI and VFA subgroups.
Results: The mean operative time, length of hospital stay, and complication rate were significantly higher in the before learning curve group than in the after learning curve group. In the subgroup analysis, complication rate and length of hospital stay did not differ according to BMI or VFA; however, for the before learning curve group, mean operative time and blood loss were significantly higher in the high VFA subgroup than in the low VFA subgroup (P=0.047 and P=0.028, respectively).
Conclusions: VFA may be a better predictive marker than BMI for selecting candidates for LG, which may help to get a better surgical outcome for inexperienced surgeons.Ⅰ. INTRODUCTION 1
Ⅱ. MATERIALS AND METHODS 3
A. Patients 3
B. Estimation of body fat compartments 3
C. Surgical technique 4
D. Statistical Analysis 4
Ⅲ. RESULTS 5
A. Patients’ Characteristics 5
B. Correlation between body mass index and body fat compartments 5
C. Subgroup analysis according to body mass index and visceral fat area 5
D. Overall survival according to obesity status and surgeon experience 6
Ⅳ. DISCUSSION 7
REFERENCES 9
LIST OF FIGURES 12
LIST OF TABLES 14Maste
Jung Chang-ho
No full text학위논문(석사)--아주대학교 일반대학원 :기계공학과,2017. 2고성능의 제품들이 개발됨에 따라 고부하, 장시간 사용에 적합한 부품이 필요하게 되었고, 이에 따라 높은 피로저항을 갖는 소재가 필요하게 되었다. 그러나 이러한 요구에 부합하는 새로운 재료는 높은 비용이 요구되며, 가공 또한 높은 기술을 필요로 한다. 이러한 이유로 소재의 변경 없이 표면 경도와 피로저항을 높일 수 있는 표면 처리 공법은 효율적이며 경제적인 방법으로 제시 되고 있다. 이 논문에서는 기존의 고주파 미세단조 공법과 레이저를 이용한 열처리 공법을 동시에 적용한 예열보조 미세단조 공법을 적용 시 일어나는 효과를 연구하였다.
기존의 고주파수 미세단조 공법은 표면에 미세한 소성 변형을 일으켜 금속 표면의 경도와 압축 잔류 응력을 증가시키는 표면처리 기술이다. 이 공정을 통해 효과적이고 비교적 간편하게 표면의 경도와 피로저항을 높일 수 있지만, 낮은 경화층 형성으로 효과가 제한적이었다. 반면 레이저 표면 개질 기술은 비 접촉 상태에서 표면 경도를 끌어올리는 공법이나, 열에 의한 취성 증가 및 잔류 응력이 남는 문제점이 있다. 이 논문에서는 이 두 가지 방법을 합하여 온도조건에 따른 미세 단조 공법의 효과를 알아보았다. AISI 4140 금속에 대하여 소성 변형과 피로 파괴에 큰 영향을 미치는 요인인 온도를 조절하여 표면처리의 효과를 연구해 보았다.
온도를 변수로 설정하여 예열보조 미세단조 표면처리 시스템을 구성하였고, 예열용 열원으로는 금속 표면 열처리용 레이저를 사용하였다. 표면 처리 위치와 레이저 조사지점을 90°로 배치하여 선반에 장착된 시편을 가공 하였다. 총 5종류의 시편(무처리 시편, 일반 열처리 시편, 상온, 400 ℃, 550 ℃ 에서 예열 보조 미세단조 처리 시편)을 비교하였고 각 효과의 차이를 피로 수명을 기준으로 비교해 보았다. 이후 단조 처리한 시편의 파단면의 SEM 측정과 개재물에 대한 EDS 분석을 시행하여 피로 파괴에 영향을 주는 요인을 연구하였다. 이 결과 표면처리를 통해 수명이 변화되고, 550 ℃ 예열보조 미세단조 시편 및 열처리 시편에서 일부 수명이 상승한 것을 확인하였고, 잔류 응력과 경도 변화를 측정하여 공정에 따른 차이를 확인 하였다.
이후 예열보조 미세단조 공법의 충격 과정을 FEM 해석을 통해 분석 하였다. 1회 충격 시, 1회전 충격 시 시편에 생성되는 잔류 응력의 분포와 크기를 확인하였다. 이 결과 시편 표면에서부터 약 0.4 mm 깊이의 영역에 대하여 잔류 응력이 형성되었으며, 상온 예열보조 미세단조 처리의 경우 856 MPa 의 압축잔류응력이 형성되었고, 550 ℃ 예열보조 미세단조 처리의 경우 1157 MPa 의 보다 높은 압축잔류응력이 형성된 것을 확인하였다. 이후 경도 측정법을 통해 계산한 잔류 응력 수치와 해석상의 잔류 응력을 비교 하였다. 그 결과 대체적으로 잔류응력의 거동이 일치하는 경향을 확인하였고, 약 예열 보조 미세 단조 처리의 경우, 463.8 MPa, 550 ℃ 예열보조 미세단조 처리의 경우 716.4 MPa 의 응력이 측정 되었다.1. 서론 1
1.1 고수명 소재의 필요성 1
1.1.1 표면 처리 기술 1
1.2 기존기술의 장단점 소개 2
1.2.1 열처리 공정 2
1.2.2 레이저 공정 3
1.2.3 샷피닝 공정 3
1.2.4 고주파수 미세 단조 공정 4
1.3 기존의 연구 내용 5
1.4 논문의 연구 내용 소개 7
2. 표면처리 공정 8
2.1 시편 준비 8
2.1.1 초음파 피로 시험 시편 10
2.1.2 실험 구성 11
2.2 미세 단조 공정 12
2.2.1 실험 장치 소개 12
2.2.2 공정 조건 13
2.3 예열 보조 미세 단조 공정 17
2.3.1 실험 장치 소개 및 실험 장비 연계 방법 17
2.3.2 레이저 공정 조건 18
2.3.3 공정 적용 온도 시험 20
3. 공정에 따른 효과 분석 21
3.1 초음파 피로 시험 22
3.1.1 기초 이론 22
3.1.2 피로시험 조건 23
3.1.3 피로시험 결과 24
3.2 표면 경도(Micro Vickers Hardness) 측정 26
3.3 파단면 분석 28
3.4 EDS 측정 32
3.5 잔류응력 측정 34
4. FEM 해석 37
4.1 물성 측정 및 선정 37
4.2 해석 설정 45
4.2.1 FE Model 45
4.2.2 Mesh 45
4.2.3 Boundary Condition 47
4.2.4 Contact Property 47
4.3 1회 충격 해석 결과 및 비교 48
4.4 회전 충격 해석 결과 및 비교 53
4.5 온도에 따른 충격 해석 결과 및 비교 58
5. 결론 61
5.1 예열 보조 미세 단조 공정 결과 61
5.2 예열 보조 미세 단조 공정의 FEM 해석 결과 63
5.3 추후 연구사항 64
참고문헌 65Maste
Seung Ho Jung
No full text학위논문(석사)--아주대학교 일반대학원 :약학,2014. 8CONTENTS
1. Introduction 1
2. Materials and Methods 12
2.1. Materials 12
2.2. Preparation of rice starch. 12
2.2.1. Preparation of thermally modified glutinous rice starch (TMR). 12
2.2.2. Preparation of spray-dried thermally modified glutinous rice starch (SDTMR). 13
2.3. Preparation of coating solution. 13
2.4. Preparation of film. 16
2.5. Preparation of film-coated tablets. 16
2.6. Characterization 18
2.6.1. Characterization of TMR and SDTMR. 18
2.6.1.1. pH of TMR and SDTMR. 18
2.6.1.2. Loss-on-drying (LOD) of TMR and SDTMR. 18
2.6.1.3. Particle size of TMR and SDTMR. 18
2.6.1.4 .Scanning electron microscopy (SEM). 19
2.6.1.5. Powder X-ray diffraction (PXRD). 19
2.6.1.6. Differential scanning calorimetry (DSC). 19
2.6.2. Characterization of film. 20
2.6.2.1. Mechanical properties of film by texture analyzer. 20
2.6.2.2. Roughness of film by CLSM. 20
2.7. Preparation of film-coated tablet. 21
2.8. Morphology of cross-sections of coated tablets (SEM). 23
2.9. In vitro dissolution study. 23
2.10. HPLC analysis of SarpogrelateHCl. 23
3. Results and discussion 26
3.1. Characterization of TMR and SDTMR powder. 26
3.1.1. pH of TMR and SDTMR. 26
3.1.2. Water content of TMR and SDTMR by LOD. 26
3.1.3. Particle size analysis of TMR and SDTMR by HELOS analysis. 28
3.1.4. Surface image of TMR and SDTMR by SEM. 30
3.1.5. Crystallinity of TMR and SDTMR by PXRD. 32
3.1.6. Thermodynamics of TMR and SDTMR by DSC. 34
3.2. Characterization of film. 36
3.2.1. Mechanical properties of film. 36
3.2.2. Roughness of film. 39
3.3. Characterization of coated tablet. 43
3.3.1. Appearance and cross section of coated tablet. 43
3.3.2. Physical properties of coated tablet. 45
3.3.3. Morphology of cross-section of coated tablet by SEM. 47
3.3.4. Physical properties of coated tablet (glycerol). 49
3.4. In vitro dissolution study. 51
4. Conclusions 56
5. References 57
국문초록 60
감사의글 62
Figure List
Fig. 1. Chemical structures of (A) amylose and (B) amylopectin. 3
Fig. 2. Mechanism of thermal modification of rice starch. 5
Fig. 3. Mechanism of plasticizer in starch structure. 6
Fig. 4. The chemical structure of SarpogrelateHCl. 10
Fig. 5. Particle sizes of TMR and SDTMR powders. 29
Fig. 6. SEM photographs of TMR and SDTMR powders. 31
Fig. 7. PXRD diffractograms of TMR and SDTMR powders. 33
Fig. 8. DSC thermograms of TMR and SDTMR powders. 35
Fig. 9. Roughness of TMR and SDTMR films by CLSM image. 40
Fig. 10. Roughness of HPMC and SDTMR films by CLSM image. 41
Fig. 11. Appearance and cross-section of coated tablets by CLSM imaging. 44
Fig. 12. Cross-section of coated tablets by SEM image. 48
Fig. 13. Dissolution profiles of SarpogrelateHCl from coated tablets in distilled water. 53
Fig. 14. Dissolution profiles of SarpogrelateHCl from coated tablets in simulated gastric fluid (pH 1.2). 54
Fig. 15. Dissolution profiles of SarpogrelateHCl from coated tablets in simulated intestinal fluid (pH 6.8). 55
Table List
Table 1. Physicochemical properties of SarpogrelateHCl. 11
Table 2. Formulation compositions for the preparation of polymeric coating solution. 15
Table 3. Formulation composition of matrix tablets. 17
Table 4. Formulation composition of matrix tablets with API. 22
Table 5. Conditions for HPLC analysis of SarpogrelateHCl. 25
Table 6. pH and LOD of TMR and SDTMR. 27
Table 7. Mechanical properties of films. 38
Table 8. Roughness index of film. 42
Table 9. Physical properties of coated tablets. 46
Table 10. Physical properties of coated tablets. 50MasterSpray-dried thermally modified rice starch was tested for its feasibility as a film-forming material with a sustained-release profile. Various coating formulations were prepared using PEG8000, HPC-LF and glycerol as plasticizers. Opadry-1, Opadry-2 and HPMC (with PEG8000 as a plasticizer) were used as reference coating formulations. The film-forming properties of these formulations were tested via application on OHP film and checking various parameters, including elongation, tensile strength and thickness. Tablets were coated with the above-mentioned formulations and checked for the appearance of film and morphology using CLSM imaging. Various mechanical properties of the tablets, including hardness, friability and size dimensions, were also analyzed. The results from these tests were analyzed, and the formulation containing glycerol was found to be best coating formulation amongst them. SDTMR containing glycerol was also coated on tablets with different coating weight gains of 3 %, 6 %, 9 %, 12 % and 15 %. SEM imaging and dissolution tests were performed to check morphologies and sustained release behaviors of the coated tablets. Tablets with higher coating weight gains showed gradual decreases in drug release in the beginning. In pH 1.2 media, the tablets showed significant sustained release of drug compared to uncoated tablets. However, in water and pH 6.8 media, the drug release rates increased rapidly later in testing, and the time for total drug release was similar to that of uncoated tablets. We conclude that SDTMR with glycerol as a plasticizer can be utilized as a film-forming agent. Further tests on dissolution involving transfer of undissolved tablets from pH 1.2 media to pH 6.8 is required to better understand the sustained-release properties of this film
The Ho-Zhao problem
No full textGiven a poset P, the set Γ(P) of all Scott closed sets ordered by inclusion forms a complete lattice. A subcategory C of Posd (the category of posets and Scott-continuous maps) is said to be Γ-faithful if for any posets P and Q in C, Γ(P) ∼= Γ(Q) implies P ∼= Q. It is known that the category of all continuous dcpos and the category of bounded complete dcpos are Γ-faithful, while Posd is not. Ho & Zhao (2009) asked whether the category DCPO of dcpos is Γ-faithful. In this paper, we answer this question in the negative by exhibiting a counterexample. To achieve this, we introduce a new subcategory of dcpos which is Γ-faithful. This subcategory subsumes all currently known Γ-faithful subcategories. With this new concept in mind, we construct the desired counterexample which relies heavily on Johnstone’s famous dcpo which is not sober in its Scott topology
Synthesis and Lithographic Characterization of Poly(hydroxystyrene-co-tert-butyl acrylate-co-3-(t-butoxycarbonyl)-1-vinylcaprolactam
No full textThe 1961 Kampong Bukit Ho Swee fire and the making of modern Singapore
No full textBy 1970, Singapore’s urban landscape was dominated by high-rise blocks of planned public housing built by the People’s Action Party government, signifying the establishment of a high modernist nation-state. A decade earlier, the margins of the City had been dominated by kampongs, home to semi-autonomous communities of low-income Chinese families which freely built, and rebuilt, unauthorised wooden houses. This change was not merely one of housing but belied a more fundamental realignment of state-society relations in the 1960s. Relocated in Housing and Development Board flats, urban kampong families were progressively integrated into the social fabric of the emergent nation-state. This study examines the pivotal role of an event, the great Kampong Bukit Ho Swee fire of 1961, in bringing about this transformation. The redevelopment of the fire site in the aftermath of the calamity brought to completion the British colonial regime’s ‘emergency’ programmes of resettling urban kampong dwellers in planned accommodation, in particular, of building emergency public housing on the sites of major fires in the 1950s. The PAP’s far greater political resolve, and the timing of and state of emergency occasioned by the scale of the 1961 disaster, enabled the government to rehouse the Bukit Ho Swee fire victims in emergency housing in record time. This in turn provided the HDB with a strategic platform for clearing other kampongs and for transforming their residents into model citizens of the nation-state. The 1961 fire’s symbolic usefulness extended into the 1980s and beyond, in sanctioning the PAP’s new housing redevelopment schemes. The official account of the inferno has also become politically useful for the government of today for disciplining a new generation of Singaporeans against taking the nation’s progress for granted. Against these exalted claims of the fire’s role in the Singapore Story, this study also examines the degree of actual change and continuity in the social and economic lives of the people of Bukit Ho Swee after the inferno. In some crucial ways, the residents continued to occupy a marginal place in society while pondering, too, over the unresolved question of the cause of the fire. These continuities of everyday life reflect the ambivalence with which the citizenry regarded the high modernist state in contemporary Singapore
Morphology and Molecular Phylogeny of the Soil Ciliate Cyrtohymena seorakensis sp. n. (Ciliophora, Hypotricha, Oxytrichidae)
No full textOmar, Atef, Jung, Jae-Ho (2020): Morphology and Molecular Phylogeny of the Soil Ciliate Cyrtohymena seorakensis sp. n. (Ciliophora, Hypotricha, Oxytrichidae). Zootaxa 4758 (3): 561-572, DOI: 10.11646/zootaxa.4758.3.
Sociocultural aspects of tuberculosis: A literature review and a case study of immigrant tuberculosis
No full text- …
