Effects of Quenching Methods and Aging Processes on the Crushing Properties and Microstructure of Al–Zn–Mg Alloy Thin-Walled Square Extrusions

Hui Guo,Jin Zhang,Cheng Wang,Yun‑lai Deng 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.8

In this study, the effects of different (online quenching and offline quenching) quenching methods and aging processes (T6and T73) on the crashworthiness and microstructural evolution of three Al–Zn–Mg alloys (G1–G3) were studied by conductingtensile test and axial compression tests at room temperature, combined with optical metallography, electron back scattereddiffraction, and transmission electron microscopy microstructural observations. The obtained results revealed that thecrushing properties of three different Al–Zn–Mg alloys subjected to different quenching methods and aging processes weresignificantly different. Their crushing energy absorption of are ranked as follows: G1 > G3 > G2. The highest total energyabsorption gap (between T6 and T73) is the G1 alloy, and the lowest one is the G3 alloy. The largest total energy absorptiongap between the two quenching methods is the G3 alloy, and the smallest one is the G1 alloy. The G2 alloy with the largesttotal amount of Zn + Mg has the highest number density of matrix precipitates, the largest precipitate gap (between T6 andT73) and the smallest precipitate gap between the two quenching methods. The G3 alloy with the largest Zn/Mg ratio hasthe smallest number density of matrix precipitates, the minimum precipitation gap (between T6 and T73) and the maximumprecipitation gap between the two quenching methods. The G1 alloy with the lowest Zn/Mg ratio has the smallest size ofgrain boundary precipitates and PFZ width, while their largest values are obtained for the G3 alloy with the maximum Zn/Mg ratio. As a crushing resistant structural material, the crushing properties is improved without reducing the strength. Theratio of Zn/Mg should be controlled within the range of 4.57–6.15, while the total amount of Zn + Mg should be controlledwithin the range of 6.18–7.01.

합금의 종류와 지대주 성분이 바형 유지 장치의 변연 적합도에 미치는 영향

이윤희,송영균,이준석 대한치과보철학회 2012 대한치과보철학회지 Vol.50 No.2

Purpose: The object of this study was to determine if the low-priced alloy and metal UCLA abutment could be available for manufacturing bar-retained framework of implant prosthesis. Materials and methods: Bar structure was classified into 4 groups, The specimen of group 1 and 2 were based on casting high noble metal alloys and noble metal alloys with gold UCLA abutment. The specimen of group 3 and 4 were based on casting noble metal alloys and base metal alloys with metal UCLA abutment. Cast bar structure was installed in an acrylic resin model and only the screw on the hexed abutment side was tightened to 20 Ncm. On the opposite side, vertical discrepancy was measured with stereo microscope from front, back, and lateral side of the implant-abutment interface. One-way ANOVA was performed to analyze the marginal fit discrepancy. Results: One-way ANOVA test showed significant differences among all groups (P<.05) except for Group 1 and 3. Among them, difference between Group 1 and 2 was noticeable. Measured vertical discrepancies were all below 70 ㎛ except to Group 2. Conclusion: Base metal alloy and metal UCLA abutment could be used as an alternative to high-priced gold alloy for implant bar-retained framework. 연구 목적: 합금의 종류와 지대주의 재질의 차이가 변연적합도에 미치는 영향을 비교 분석하고자 한다. 연구 재료 및 방법: 2개의 임플란트 유사체를 평행하게 위치시킨 후 아크릴릭 레진으로 포매하여 연구모형을 제작하였다. 바 구조물은 gold UCLA 지대주에 고귀금속 합금(high noble metal alloy)과 귀금속 합금(noble metal alloy)을, 그리고 metal UCLA 지대주에 고귀금속 합금과 비귀금속 합금(base metal alloy)을 이용하여 총 4 종류의 바 구조물을 7개씩 시편을 제작하였다. 주조된 바 구조물을 레진 모형에 장착하고 한쪽 지대나사를 조인 후, 반대쪽 임플란트-지대주 간극의 수직 거리를 앞, 뒤, 측면 3부위에서 입체 광학 현미경으로 관찰하여 기록하였다. 결과: 각 군들의 변연오차 평균값은 gold UCLA 지대주에 고귀금속 합금과 귀금속 합금을 사용했을 때 각각 13.69 ± 6.74 ㎛와 267.26 ± 65.85 ㎛이었으며, metal UCLA 지대주에 고귀금속 합금과 비귀금속 합금을 사용했을 때 26.19 ± 8.14 ㎛와 61.90 ± 33.65 ㎛이었다. One-way ANOVA를 이용하여 변연 적합도의 차이를 분석했을 때 고귀금속 함금을 사용한 군들을 제외하고, 모든 군간에 유의한 차이가 존재하였다(P<.05). Gold UCLA 지대주-귀금속 합금 조합을 제외하고 모두 70 ㎛ 이하의 수직오차를 보였다. 결론: 임플란트 바 유지 장치의 제작에 있어서 고귀금속 합금 대신 비귀금속 합금과 metal UCLA 지대주를 사용하는 것은 임상적 타당성이 있다고 판단된다.

쌍각자궁에서 4회 반복유산 후 만삭 둔위 분만 1예

홍정의,김윤숙,최승도,선우재근,배동한 순천향의학연구소 2008 Journal of Soonchunhyang Medical Science Vol.14 No.2S

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<남정팔난기> 유통 형태의 변화와 의미

최윤희 우리어문학회 2003 우리어문연구 Vol.21 No.-

<NamJeongPalNanGi> is the work which clearly shows a change of distribution form. <NarqJeongPalNanGi> is a long piece novel of 14 section 14 volume. It was published for commercial lent and in a woodblock-printed book form. This paper studies that features of <NamJeongPalNanGi> went thorough changes of distribution form, that is, a book of pen-manship, a woodblock-printed book form and a printing type. Furthermore, the paper considers how the tendency of the work was transformed while the distribution form changed and how is the sense of beauty of readers and writers which was reflected <NamJeongPalNanGi>. I have found a multilateral faces of <NamJeongPalNanGi> and aspects of changes of the work historically and contemporarily through the study. And it was an opportunity to inquire into one example of a movement and change of old novels in the late Yi Dynasty the, as well. Thus is the meaning of this paper. This paper was proceeded as follows. First, the paper studied each variant text forms of <NamJeongPalNanGi> and classified them. Secondly the paper considers what characteristics of each variant texts are and how those transformed and the meaning of these developments. <NamJeongPalNanGi> are classified 14seCtion 14volume type→3section 3volume type→woodblock→printed book type(㉮→㉯→㉰) in order. long piece novels such as, 14section 14volume, were shortened to 3section 3volume and this change did not mean only shortening of the length. Changes came from distribution form of variant texts are classified to the change of narration view a b u t a hero, the change of war-story narration, the change of the later part of hero's life narration. First of all, a multiple main Character appears in the ㉮type, and their role is pretty important. However, their role was deleted or shrinked in the ㉯type and ㉰type. as a result of this, it was focused on a person called HwangGeuk. A personal hero was emphasized and one character was focused. Secondly, changes appeared in GunDam. Various kinds of war, strategy, tactics, Taoistic magic were frequently described in ㉮tYpe. shortenings and eliminations took place in GunDam novel such as, the ㉯type and the ㉰type. The shortening and elimination of war-story show some features as follows, Shortenings and eliminations pretty often took place in war-stories with southern barbarians. On the contrary, Taoistic magic or disposition of troops were less deleted. This means that stories became focused on the popular imagination than the interest through emperical imagination. Lastly, the part of HuIlDam which had been largely described by one sixth of the whole novel was been sharply decreased or eliminated in the ㉯series (This paper has excluded the ㉰series from the reference). This means that concerns of writers and readers decreased in the ending and their life after the success of characters. That is, we realize that the interest of writers and readers transferred to distinguish themselves rather than the enjoyment after the success. In brief, we can find signs of features of a group of here novels which were woodblock-printed started to appear features which partially extricated after the 18th century. Woodblock-printed type(even though they are missing volume) became close to hero novels which sought for the distribution for commercial popularity in stead of being eliminated features of long piece novel. The feature of works changed according to the distribution form change and this change was the compromise with expectation of writers and readers. In conclusion, <NmJeongPalNanGi> shows that the relation between changes of novel formand the expectation of writers and readers.

설측 복합레진 색상이 치아 순측 색상에 미치는 영향

문승희,박수정,조현구,황윤찬,오원만,황인남 大韓齒科保存學會 2009 Restorative Dentistry & Endodontics Vol.34 No.4

본 연구는 순면 잔존 치질의 두께와 후방 복합레진의 색상이 최종 수복된 치아표면의 색상에 미치는 영향을 알아보고자 시행하였다. 배경판으로 사용될 복합레진은 Filtek Supreme (3M ESPE, St. Paul, U.S,A.)의 Al, A2, A6D, Bl, B2, B3,C1, C2 C6D를 선택하였다. 배경판으로 사용될 복합레진 시편은 직경 10 mm, 두께 4.5 mm로 각 shade당 한 개씩 제작하였다. 순면 잔존 치질은 상악 중절치 치관의 순면을 제외한 나머지 부위를 아크릴릭 레진을 이용하여 매몰 후 저속의 Diamond Wheel Saw (Isomet ; Buehler Ltd, Lake Bluff, U.S.A.)를 이용하여 주수 하에 순면으로부터 2.5 mm 두께로 절단하였다. 절단된 상아질측 표면을 2000번 사포로 연마하여 2.2 mm 두께의 시편을 얻었다. 분광광도계 Spectrolino^(Ⓡ) (Serial No. 3257-18522, GretagMacbeth, Regensdorf, Switzerland)를 이용하여 치아시편을 9개의 복합레진 시편위에 접촉면에 수분이 있는 상태로 위치시켜 치아 순면색상을 측정하였다. 그 후, 치아시편의 상아질 측면을 1.0 mm까지 0.3 mm 간격으로 연마하면서 복합레진 시편위에 위치시켜 동일한 방법으로 색상을 측정하였다. 모든 시편에서 L^(*)값과 b^(*)값은 배경색에 무관하게 치아시편의 두께가 두꺼워질수록 증가하는 양상을 보였으나(p <0.05), a^(*)값은 배경색에 무관하게 두께에 따른 유의한 차이를 보이지 않았다. In this study we evaluated the influence of both the thickness of residual enamel and the color of the composite resins applied to lingual surface on the labial surface color. Background plates were made by randomly (Al, A2, A6D, Bl, B2, B3, Cl, C2, C6D) selected colors of Filtek Supreme (3M ESPE, St. Paul, U.S.A.) composite resin. Crown portion of 9 maxillary central incisors were cut off and embedded with acrylic resin except labial surface. Samples of average thickness of 2.2 mm were obtained after cutting it in a thickness of 2.5 mm from the labial surface and sandpaper polish. The shade of composite resin background was measured using Spectrophotometer (Spectrolino^(Ⓡ), GretagMacbeth, Regensdorf, Switzerland). And CIE L^(*)a^(*)b^(*) value of 2.2 mm thickness tooth samples were measured on the 9 composite resin backgrounds. And then, the cutting side of tooth samples was ground to the extent of 1.9 mm, 1.6 mm, 1.3 mm, 1.0 mm and placed on composite resin backgrounds and measured L^(*)a^(*)b^(*) values with the same method. In all samples, L^(*) value and b^(*) value seemed to have a tendency of decreasing as thickness of tooth sample becomes thinner regardless of background colors (p < 0.05). But, a^(*) value didn't show the significant differences depending on the thickness.

《四庫全書總目提要》子部儒家類所反映的學術思想傾向

唐潤熙 韓國中國語文學會 2004 中國文學 Vol.41 No.-

The bibliographies of ≪The Bibliography of Complete Collection of Four Treasuries≫ are composed of Chinese chronical academic trend and concrete classic books. To understand the ≪The Bibliography of Complete Collection of Four Treasuries≫, we are supposed to conceive the assortments and the functions of it, which include the Chinese classical academic thoughts inside. This article focused on the Confucian bibliographies and explained the functions of bibliography such as revealing the origin of Confucian school, discriminating the core of Confucian school, discussing the change and development of the school, comparing the difference of the schools, and judging goods and bads. At the end we can tell that the Confucian bibliographies of ≪The Bibliography of Complete Collection of Four Treasuries≫ were influenced by the cultural policies of Qing Dynasty, intended to make Cheng and Zhu's new confucianism more important and Qing Dynasty more stable.

산유체모델에 의한 Building downwash 현상 해석

구윤서,최상민,이진호,윤희영 안양대학교 산업기술연구소 2000 自然科學硏究 Vol.7 No.-

본 연구에서는 굴뚝주변에 위치한 건물에 의한 세류현상을 보다 정확히 모사하기 위해서 전산유체모델을 이용하였다. 계산 신뢰도를 검증하기 위해서 전산모델 계산치와 1993년 Thompson의 추적자 실험에 의한 실측치 및 대기 환경영향평가에 많이 사용되는 ISCST3 모델 계산치와 각각 비교하였다. ISCST3에서는 건물의 영향을 고려하기 위하여 BPIP을 이용, 건물의 높이와 폭을 결정하여 모델링을 수행하였다. 전산유체모델에서는 건물을 형상화시키고 굴뚝에서 오염물질을 배출시켜 확산 계산을 하였다. 전산유체모델로 모사한 결과, 건물의 후면에 wake가 발생하는 것을 볼 수 있었고, wake zone의 길이는 건물 높이의 약 2배가 되었다. 오염물질 농도를 비교한 결과 ISCST에서는 최대 농도값과 착지점이 일치하지 않았으나, 전산유체모델로 계산한 결과는 추적자 실험치와 거의 일치한 값을 나타냈다. This study used the computational fluid dynamic(CFD) for describing a dispersion influenced by building downwash. We compared calculated concentrations with Thompson's tracer experiment and ISCST3 models. In calculating ISCST3 model, BPIP(Building Profile Input Program) was used to estimate building heights & widths corresponding to a specific wind direction. Results show that ISCST3 model is not appropriate to describe the building downwash but CFD model, which calculates the flow fields and dispersions simultaneously, is in good agreement with tracer measurements. In order to describe the dispersion induced by building wake near the stack, it is recommended to use CFD model.

좌측 전대뇌동맥 영역의 뇌경색 후 발생한 초피질성 혼합 실어증 1예

심미섭,이연수,김은희,이인숙,한설희 대한치매학회 2003 Dementia and Neurocognitive Disorders Vol.2 No.1

We present a case of transcortical mixed aphasia (TMA) presumably caused by left anterior cerebral artery infarction. A 53-year-old, right-handed woman suddenly developed speech disturbance and abnormal behavior. Her spontaneous speech was remarkably reduced to almost mutistic state and objective naming, comprehension, reading and writing were severely impaired. However, repetition of phonemes and sentences were fully preserved. She showed echolalia and completion phenomenon, which prompted us to make a diagnosis of TMA. Although the lesion was confined to extrasylvian area on MRI, SPECT demonstrated diminished blood flow left perisylvian cortices suggestive of functional isolation of speech area. In spite of her echolalic repetition, she couldn't repeat affective prosody, presumably, because of the left anterior corpus callosal lesion. Treatment with bromocriptine, a dopamine agonist helped her recovery of behavioral changes, namely abulia or akinetic mutism consisitent with mesial frontal syndrome.

Association of Polymorphisms in Stress-Related TNFα and NPY Genes with the Metabolic Syndrome in Han and Hui Ethnic Groups

Bu, De-Yun,Ji, Wen-Wu,Bai, Dan,Zhou, Jian,Li, Hai-Xia,Yang, Hui-Fang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.14

Background: Metabolic syndrome (MS) is a cluster of complicated disorders caused by the interactive influencing factors of heredity and environment, which predisposes to many cnacers. Results from epidemic research indicate that stress is tightly related to the pathogenesis of MS and neoplasia. This paper aims to investigate the association between psychological stress and MS with respect to the tumor necrosis factor alpha (TNF${\alpha}$) and neuropeptide Y (NPY) genes in the Han and Hui ethnic groups. Methods: All subjects for this case-control study matched strict enrollment criteria (nationality, gender and age) and lived in the city of Wu Zhong of Ningxia Province in China. The enrolled group contained 102 matched pairs of Hui ethnic individuals and 98 matched pairs of Han ethnic individuals. Enrolled subjects completed the general Symptom Checklist-90 (SCL-90). The TNF${\alpha}$-308G/A variant and NPYrs16147 polymorphism were detected in case (81 males, 119 females) and control (81 males, 119 females) groups by polymerase chain reaction (PCR) amplification. Results: Nine factors of the SCL-90 were found to be statistically different (p<0.05) between case and control groups. The homozygous mutant genotype (AA) and the mutant allele (A) of the TNF${\alpha}$-308G/A gene were less frequently observed in the control population compared to the case group. The odds ratio (95% confidence interval) in "Allele" for MS was 2.28 (1.47-3.53), p=0.0001, while "OR" was 1.11 (0.83-1.47), p=0.15, for the NPYrs16147 gene polymorphism. Conclusions: Psychological stress has been positively associated with MS. A previous study from our group suggested there were differences in the level of psychological stress between Hui and Han ethnic groups. Furthermore, we found that the stress-related TNF${\alpha}$ gene was associated with MS for both Han and Hui ethnic groups. In contrast, NPY may be a possible contributor to MS and associated cancer for the Han ethnic group.

Anti-Helicobacter pylori Activities of IgY

Yun-Hui Yang,Dongsun Park,Jangbeen Kyung,Dajeong Kim,Sun Hee Lee,Ehn-Kyoung Choi,Seock-Yeon Hwang,Yun-Bae Kim 한국실험동물학회 2012 한국실험동물학회 학술발표대회 논문집 Vol.2012 No.2