• Title/Summary/Keyword: growth behavior

Search Result 2,662, Processing Time 0.025 seconds

Evaluation of Fracture Behavior of Adhesive Layer in Fiber Metal Laminates using Cohesive Zone Models (응집영역모델을 이용한 섬유금속적층판 접착층의 모드 I, II 파괴 거동 물성평가)

  • Lee, Byoung-Eon;Park, Eu-Tteum;Ko, Dae-Cheol;Kang, Beom-Soo;Song, Woo-Jin
    • Composites Research
    • /
    • v.29 no.2
    • /
    • pp.45-52
    • /
    • 2016
  • An understanding of the failure mechanisms of the adhesive layer is decisive in interpreting the performance of a particular adhesive joint because the delamination is one of the most common failure modes of the laminated composites such as the fiber metal laminates. The interface between different materials, which is the case between the metal and the composite layers in this study, can be loaded through a combination of fracture modes. All loads can be decomposed into peel stresses, perpendicular to the interface, and two in-plane shear stresses, leading to three basic fracture mode I, II and III. To determine the load causing the delamination growth, the energy release rate should be identified in corresponding criterion involving the critical energy release rate ($G_C$) of the material. The critical energy release rate based on these three modes will be $G_{IC}$, $G_{IIC}$ and $G_{IIIC}$. In this study, to evaluate the fracture behaviors in the fracture mode I and II of the adhesive layer in fiber metal laminates, the double cantilever beam and the end-notched flexure tests were performed using the reference adhesive joints. Furthermore, it is confirmed that the experimental results of the adhesive fracture toughness can be applied by the comparison with the finite element analysis using cohesive zone model.

A Study on the Heat Release Characteristics of Fire Load for Performance Based Design of Multiplexes: A Focus on the Heat Release Rate and Fire Spread Rate of Cinema Seats (복합영상관의 성능위주설계를 위한 가연물의 연소발열특성 연구: 객석의자의 열발생률 및 연소확산속도를 중심으로)

  • Nam, Dong-Gun;Jang, Hyo-Yeon;Hwang, Cheol-Hong;Lim, Ohk-Kun
    • Fire Science and Engineering
    • /
    • v.34 no.1
    • /
    • pp.11-17
    • /
    • 2020
  • As performance-based design (PBD) has a direct impact on evacuation safety assessments, designing fire scenarios based on real fire tests is essential. To improve the reliability of the PBD for fire safety in multiplexes, information on fire behavior, such as heat release rate (HRR) and fire spread rate, are provided in this study by conducting a standard fabric flammability test. To this end, several chairs were arranged in a pattern that resembled a theater-style seating. The peak HRR and heating value per unit mass for each chair ranged from 415 kW to 988 kW and 15.2 MJ/kg to 23.8 MJ/kg, respectively. The heating values per unit mass of the new and old chairs were 23.6 MJ/kg and 16.7 MJ/kg, respectively. As the quantity of plastic and cushioning materials in the new chairs was more than that of the old ones, the new chairs were more vulnerable to fire hazards. Furthermore, when the chairs were arranged in a line, the fire spread rate was observed to be 0.39-0.42 m/min, regardless of the ignition location. Finally, a fire growth curve showing the peak HRR and fire spread rate was also demonstrated.

Secretion and Expression of Matrix Metalloproteinase-2 and 9 from Bone Marrow Mononuclear Cells in Myelodysplastic Syndrome and Acute Myeloid Leukemia

  • Chaudhary, Ajay K;Chaudhary, Shruti;Ghosh, Kanjaksha;Shanmukaiah, Chandrakala;Nadkarni, Anita H
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.17 no.3
    • /
    • pp.1519-1529
    • /
    • 2016
  • Background: Matrix metalloproteinase -2 (gelatinase-A, Mr 72,000 type IV collagenase, MMP-2) and -9 (gelatinase-B, Mr 92,000 type IV collagenase, MMP-9) are key molecules that play roles in tumor growth, invasion, tissue remodeling, metastasis and stem-cell regulation by digesting extracellular matrix barriers. MMP-2 and -9 are well known to impact on solid cancer susceptibility, whereas, in hematological malignancies, a paucity of data is available to resolve the function of these regulatory molecules in bone marrow mononuclear cells (BM-MNCs) and stromal cells of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Objectives: The present study aimed to investigate mRNA expression and gelatinase A and B secretion from BM-MNCs in vitro and genotypic associations of MMP-2 (-1306 C/T; rs243865), MMP-9 (-1562 C/T; rs3918242), tissue inhibitor of metalloproteinase -1 (TIMP-1) (372T/C; rs4898, Exon 5) and TIMP-2 (-418G/C; rs8179090) in MDS and AML. Results: The study covered cases of confirmed MDS (n=50), AML (n=32) and healthy controls (n=110). MMP-9 mRNA expression revealed 2 fold increased expression in MDS-RAEB II and 2.5 fold in AML M-4 (60-70% blasts). Secretion of gelatinase-B also revealed the MMP-9 mRNA expression and ELISA data also supported these data. We noted that those patients having more blast crises presented with more secretion of MMP-9 and its mRNA expression. In contrast MMP-9 (-1562 C/T) showed significant polymorphic associations in MDS (p<0.02) and AML (p<0.02). MMP-9 mRNA expression of C/T and T/T genotypes were 1.5 and 2.5 fold increased in MDS and AML respectively. In AML, MMP-2 C/T and T/T genotypes showed 2.0 fold mRNA expression. Only MMP-9 (-1306 C/T) showed significant 4 fold (p<0.001) increased risk with chemical and x-ray exposed MDS, while tobacco and cigarette smokers have 3 fold (p<0.04) risk in AML. Conclusions: In view of our results, MMP-9 revealed synergistic secretion and expression in blast crises of MDS and AML with 'gene' polymorphic effects and is significantly associated with increased risk with tobacco, cigarette and environmental exposure. Release and secretion of these enzymes may influence hematopoietic cell behavior and may be important in the clinical point of view. It may offer valuable tools for diagnosis and prognosis, as well as possible targets for the treatments.

Expression of Transcription Factor FOXC2 in Cervical Cancer and Effects of Silencing on Cervical Cancer Cell Proliferation

  • Zheng, Chun-Hua;Quan, Yuan;Li, Yi-Yang;Deng, Wei-Guo;Shao, Wen-Jing;Fu, Yan
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.4
    • /
    • pp.1589-1595
    • /
    • 2014
  • Objective: Forkhead box C2 (FOXC2) is a member of the winged helix/forkhead box (Fox) family of transcription factors. It has been suggested to regulate tumor vasculature, growth, invasion and metastasis, although it has not been studied in cervical cancer. Here, we analyzed FOXC2 expression in cervical tissues corresponding to different stages of cervical cancer development and examined its correlation with clinicopathological characteristics. In addition, we examined the effects of targeting FOXC2 on the biological behavior of human cervical cancer cells. Methods: The expression of FOXC2 in normal human cervix, CIN I-III and cervical cancer was examined by immunohistochemistry and compared among the three groups and between cervical cancers with different pathological subtypes. Endogenous expression of FOXC2 was transiently knocked down in human Hela and SiHa cervical cells by siRNA, and cell viability and migration were examined by scratch and CCK8 assays, respectively. Results: In normal cervical tissue the frequency of positive staining was 25% (10/40 cases), with a staining intensity (PI) of $0.297{\pm}0.520$, in CIN was 65% (26/40cases), with a PI of $3.00{\pm}3.29$, and in cancer was 91.8% (68/74 cases), with a PI of $5.568 {\pm}3.449$. The frequency was 100% in adenocarcinoma (5/5 cases) and 91.3% in SCCs (63/69 cases). The FOXC2 positive expression rate was 88.5% in patients with cervical SCC stage I and 100% in stage II, showing significant differences compared with normal cervix and CIN. With age, pathologic differentiation degree and tumor size, FOXC2 expression showed no significant variation. On transient transfection of Hela and SiHa cells, FOXC2-siRNA inhibition rates were 76.2% and 75.7%; CCK8 results showed reduced proliferation and relative migration (in Hela cells from $64.5{\pm}3.16$ to $49.5{\pm}9.24$ and in SiHa cells from $60.1{\pm}3.05$ to $44.3{\pm}3.98$) (P < 0.05). Conclusion: FOXC2 gene expression increases with malignancy, especially with blood vessel hyperplasia and invasion degree. Targeted silencing was associated with reduced cell proliferation as well as invasion potential.

A Study of father's care giving in infancy (아버지의 영아 돌봄에 관한 문헌연구)

  • Kim, Young-Hee
    • Korean Parent-Child Health Journal
    • /
    • v.1
    • /
    • pp.75-87
    • /
    • 1998
  • These days social and economical changes have influence on the structure of family and the role of family members. Working mothers and widowers with children are increasing because of economical difficulties. Support from relatives are decreasing because of the conspicuous trend toward nuclear families. According to these reasons androgynous fathers are required. Today's fathers in Korea socially and culturally have learned about traditional parenting, but they are changing their fathering styles to meet the demands of the times. However they don't have their own fathering models. Therefore nurses who hold an advantageous position to teach and support from clinic have to encourage them to care their infants. The purposes of this study were to define father's care giving in infancy, understand influencing factors on fathering, and the differences between fathering and mothering, then contribute to nursing implementation for supporting fathers. This study was designed to review references about father's care giving. The results were follows: Six aspects of parent participation were direct care. indirect care, play, decision-making concerning the child, amount of time of sole responsibility for the child and overall availability to the child. Direct care involved feeding, bathing, going to child if child awakens. dressing, putting child to bed, taking child to doctor, nurse, or dentist, transporting child to and from sitter, day care, or school, washing child's hair. Indirect care involved cleaning up after child, preparing child's food, fixing child's broken playthings, washing child's clothes, arranging baby-sitting, shopping for child's toys and clothes, transporting baby-sitter to and from your home. Young fathers were gradually participating in direct care like feeding, taking child to doctor. Father's care giving stimulated mothering and promoted parent-infant relationship. Influencing factors of fathering would be divided into father characteristics, surrounding factors, infant attributes. Father characteristics were age, role perception, relationship with parent. Surrounding factors were the opportunity of early contact, support system, spouse's expectation, marital adjustment, feeding type, past experience of care giving. Infant attributes were temperament, behavior, age, sex. The differences between fathering and mothering were reviewed. Fathers were poor at care giving. but their caring was similar to mother's. This subtle difference positively worked upon infant's growth and development. On the basis of these theoretical data, nurses can empower fathers to cooperate with mothers in caring infants.

  • PDF

Development of Water Hammer Simulation Model for Safety Assessment of Hydroelectric Power Plant (수력발전설비의 안전도 평가를 위한 수충격 해석 모형 개발)

  • Nam, Myeong Jun;Lee, Jae-Young;Jung, Woo-Young
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.21 no.1
    • /
    • pp.760-767
    • /
    • 2020
  • Sustainable growth of hydroelectric power plants is expected in consideration of climate change and energy security. However, hydroelectric power plants always have a risk of water hammer damage, and safety assurance is very important. The water hammer phenomenon commonly occurs during operations such as rapid opening and closing of the valves and pump/turbine shutdown in pipe systems, which is more common in cases of emergency shutdown. In this study, a computational numerical model was developed using the MOC-FDM scheme to reflect the mechanism of water hammer occurrence. The proposed model was implemented in boundary conditions such as reservoir, pipeline, valve, and pump/turbine conditions and then applied to simulate hypothetical case studies. The analysis results of the model were verified using the analysis results at the main points of the pipe systems. The model produced reasonably good performance and was validated by comparison with the results of the SIMSEN package model. The model could be used as an efficient tool for the safety assessment of hydroelectric power plants based on accurate prediction of transient behavior in the operation of hydropower facilities.

Plagiarism dispute Cases of Fashion Design and Undergraduate Students' Perceptions Regarding Plagiarism of Fashion Design (패션디자인의 표절 분쟁 사례와 대학생들의 패션디자인 표절에 대한 인식)

  • Kim, Jang-Hyeon
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.21 no.10
    • /
    • pp.480-489
    • /
    • 2020
  • Controversy and legal disputes over counterfeit fashion designs have recently arisen in the fashion industry. The purpose of this study is to examine cases of counterfeiting disputes over fashion designs, and how the perception of counterfeit fashion designs is fostered from the learner's point of view, suggesting implications for the counterfeiting problem. As a result of this study, first, counterfeiting disputes over fashion design started from a lack of utilization of the Design Protection Act and the ambiguity in counterfeit design criteria. Second, the negative perceptions of counterfeit designs were mainly about unethical behavior, inhibiting the growth of the fashion industry, and reducing consumers' willingness to buy the genuine article. Positive perceptions were mainly about the process of creation, the promotion of a developmental environment for the fashion industry, and the expansion of opportunities to promote new designs. The most common perception was the absence of clear criteria for judgments about counterfeiting. Third, the implications of the counterfeiting problem in fashion design require effective institutional improvement in the fashion industry, the establishment of standards to deal with counterfeiting, the development and practical introduction of education proposals regarding intellectual property rights, and changing the perception of counterfeiting in the fashion industry.

Motives, Strategies and Patterns of Foreign Direct Investment : The Case of Japanese and Korean Firms

  • Park, Kang-H.;Lim, Yong-Taek
    • International Commerce and Information Review
    • /
    • v.7 no.4
    • /
    • pp.387-407
    • /
    • 2005
  • This paper is to study globalization motives and strategies of Japanese and Korean industries by analyzing the causes and patterns of foreign direct investment (FDI) of the firms of the two countries during the 1980s and 1990s. First we develop a FDI function from the profit maximizing model of firms. Then we use regression analysis to determine internally driving-out factors and externally-inducing factors. Japanese FDI strategy has gone through three different stages; from natural resource-seeking investment in the 1950s and 1960s to market-expansion investment in the 1970s and 1980s and to a combination of cost-reducing (low-cost labor-seeking) investment and market-penetrating investment in the 1990s. On the other hand, Korean FDI behavior has gone through four different stages; from the learning stage with small investments in the 1970s, to natural resource-seeking investment in the early and mid 1980s, to the growth stage in the late 1980s and the early 1990s, to the maturity stage of the mid and late 1990s. The last two stages were characterized by a combination of cost-reducing investment and market-seeking investment. As a late comer, Korea began its FDI two decades later than Japan, but caught up the patterns of Japanese FDI by the mid 1990s and is in a competing position with Japan. Our findings show that both Japanese FDI and Korean FDI in Asia and other developing countries tendto be in labor-intensive sectors where their firms are losing their comparative advantages at home. The main motive for FDI into these regions is low-cost resource seeking. On the other hand, both Japanese FDI and Korean FDI in the U.S. and Europe tend to be knowledge-intensive sectors where Japanese and Korean firms attempt to internalize transaction and information costs by globalizing its production. The main motive for FDI into these regions is market-seeking. Firms in both countries have increased their investments in Mexico and Western and Eastern Europe in order to penetrate large economic blocs such as the EU and NAFTA area. Korean firms are more aggressive in expanding into new and untested markets than are their counterpart in Japan. Evidence of this can be seen in the scarcity of Japanese FDI and abundance of Korean FDI in Eastern Europe and China.

  • PDF

A CASE REPORT AND RIVIEW OF LITERATURE ON OSSIFYING FIBROMA IN MAXILLA (상악골에 발생한 화골성 섬유종의 증례보고 및 문헌고찰)

  • Lee, Sang-Chull;Kim, Yeo-Gab;Ryu, Dong-Mok;Yoon, Ok-Byung
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.11 no.2
    • /
    • pp.29-39
    • /
    • 1989
  • Ossifying fibroma is a relatively slow growing tumor, and likely to have presented for some years before its clinical diognosis. The usually well circumscribed nature of ossifying fibroma in jaws lends itself to relative ease of excision and hence the favorable therapeutic results. On occasion, however, particulary in juvenile patient, if maxilla the tumor assumes an aggressive behavior. In that case, because the tumor grows invasively, resection with a margin of healthy tissue is indicated. The case presented is 34 - year old female. The patient had noticed a gradual swelling of the right side of the face approximately 2 months in duration correlation with a intermittent pain on the right maxillary molar area. Palpation disclosed firm swelling on the right anterior and lateral walls of the maxillary sinus extended to the maxillary tuberosity area. The radiographic examination revealed soft tissue mass with multiple dense round calcifications with destruction of anterior and posterolateral wall of the right maxillary sinus and right alveolar process, and hard palate. The mass totally obliterated maxillary sinus and extended to the pterygopalatine fossa. The histologic diagnosis from the biopsied specimen revealed ossifying fibroma. The tumor mass was resected by subtotal maxillectomy procedure due to a recent rapid infiltrative growth. In 5 months of postoperative follow - up period, the patient has favorable prognosis.

  • PDF

Mineralogical Characteristics of Calcite observed in the KAERI Underground Research Tunnel (고준위폐기물 지하처분연구시설(KURT)에서 관찰되는 방해석의 광물학적 특징)

  • Lee, Seung-Yeop;Baik, Min-Hoon;Cho, Won-Jin
    • Journal of the Mineralogical Society of Korea
    • /
    • v.19 no.4 s.50
    • /
    • pp.239-246
    • /
    • 2006
  • KAERI Underground Research Tunnel (KURT) was recently constructed through the site investigation from the yea. of 2003 at KAERI site, Dukjin-dong, Yuseong-gu, Daejeon city. The geo-logic setting of the site has been slightly metamorphosed. There are small fractures developed in the rock and several kinds of secondary filling minerals exist in the fractures. We examined mineralogical characteristics of fracture-filling calcite, which is not only largely distributed, but also can significantly affect the radionuclides migration. The calcite is found along fractures like other secondary minerals, forming thick veins in part. Most calcite-filled fractures contain quartz, iron oxides, and dolomite as minor minerals. The calcite crystals show an characteristic appearance with an uniformly oriented growth, coated with goethite on the edge and the etch-pit sites of their surface. Some calcite crystals have been newly formed by the precipitation of elements dissolved from the tunnel shotcrete wall, and their morphology changed according to the chemistry and flow of groundwater. The calcite can modify the groundwater chemistry and significantly affect the sorption behavior of radionuclides. The characteristic crystal structure and surface morphology of the calcite examined in the KURT site will be used as important basic data for the radionuclide migration experiment in the future.