• Title/Summary/Keyword: step-stress

Search Result 836, Processing Time 0.03 seconds

Analysis of Internal Pressure Capacity of Modular Containment Structure for Small Modular Reactor (소형 원자로용 모듈화 격납구조의 내압성능 분석)

  • Park, Woo-Ryong;Yhim, Sung-Soon
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.20 no.8
    • /
    • pp.362-370
    • /
    • 2019
  • The internal pressure capacity of a modular containment structure requires analysis to prevent the release of radioactive material in the case of an accident. To analyze the capacity, FEM models were prepared while considering the tendon arrangements and the contact surfaces between precast concrete modules, and then static analyses were carried out. The changing characteristics in the displacement and stress under step-wise loading were analyzed, along with the effects of selected parameters. For comparison, the capacity of a monolithic containment structure was also analyzed. Parametric analyses were done to suggest ranges of parameters such as the tendon force, tendon spacing, tendon location in concrete thickness direction, friction coefficient, and concrete thickness. The tendon force and frictional force provide a combined effect between contact surfaces of modules. The same level of internal pressure capacity can be secured even in the modular containment structure as in the monolithic containment structure by increasing the tendon force with additional tendons.

Experimental Study on the Drawbar Pull and Structural Safety of an Onion Harvester Attached to a Tractor (트랙터 부착형 양파수확기의 작업 속도에 따른 견인 부하와 구조 안정성에 관한 실험적 연구)

  • Shin, Chang-Seop;Kim, Jun-Hee;Ha, Yu-Shin;Park, Tusan
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.18 no.4
    • /
    • pp.16-25
    • /
    • 2019
  • Recently, due to labor shortages in rural areas within South Korea, the demand for upland-field machinery is growing. In addition, there is a lack of development of systematic performance testing of upland-field machinery. Thus, this study examined structural safety and drawbar pull based on soil properties, as a first step for systematic performance testing on the test bed. First, the properties of soil samples from 10 spots within the experimental site were examined. Second, the strain was measured and converted into stress on 8 points of an onion harvester that are likely to fail. More specifically, the chosen parts are linked to the power, along with the drawbar pull, using a 6-component load cell equipped between the tractor and the onion harvester. The water content of the soil ranged between 5.7%-7.5%, and the strength between 250-1171 kPa. The test soil was subsequently classified into loam soil based on the size distribution ratio of the sieved soil. The onion harvester can be considered as structurally safe based on the derived safety factor and the drawbar pull of 115-1194 kgf, according to the working speed based on agricultural fieldwork.

Geomechanical assessment of reservoir and caprock in CO2 storage: A coupled THM simulation

  • Taghizadeh, Roohollah;Goshtasbi, Kamran;Manshad, Abbas Khaksar;Ahangari, Kaveh
    • Advances in Energy Research
    • /
    • v.6 no.1
    • /
    • pp.75-90
    • /
    • 2019
  • Anthropogenic greenhouse gas emissions are rising rapidly despite efforts to curb release of such gases. One long term potential solution to offset these destructive emissions is the capture and storage of carbon dioxide. Partially depleted hydrocarbon reservoirs are attractive targets for permanent carbon dioxide disposal due to proven storage capacity and seal integrity, existing infrastructure. Optimum well completion design in depleted reservoirs requires understanding of prominent geomechanics issues with regard to rock-fluid interaction effects. Geomechanics plays a crucial role in the selection, design and operation of a storage facility and can improve the engineering performance, maintain safety and minimize environmental impact. In this paper, an integrated geomechanics workflow to evaluate reservoir caprock integrity is presented. This method integrates a reservoir simulation that typically computes variation in the reservoir pressure and temperature with geomechanical simulation which calculates variation in stresses. Coupling between these simulation modules is performed iteratively which in each simulation cycle, time dependent reservoir pressure and temperature obtained from three dimensional compositional reservoir models in ECLIPSE were transferred into finite element reservoir geomechanical models in ABAQUS and new porosity and permeability are obtained using volumetric strains for the next analysis step. Finally, efficiency of this approach is demonstrated through a case study of oil production and subsequent carbon storage in an oil reservoir. The methodology and overall workflow presented in this paper are expected to assist engineers with geomechanical assessments for reservoir optimum production and gas injection design for both natural gas and carbon dioxide storage in depleted reservoirs.

A study on Factors Influencing COVID-19 on depression and anxiety in university students (코로나-19가 대학생의 우울과 불안에 미치는 영향 요인 연구)

  • Chun, Yeol-Eo;Hwang, Hye-Young;Lee, Ha-Neung
    • Journal of the Korea Convergence Society
    • /
    • v.13 no.4
    • /
    • pp.583-591
    • /
    • 2022
  • In this study, the depression and anxiety of university students in the COVID-19 situation were identified, and the effects on depression and anxiety were indicated. Subjects were chosen randomly, and for the method a step selection multiple regression analysis was used. As a result of checking the factors affecting the subjects' general characteristics, stress level, preventive rule compliance level, and daily vitality level on depression and anxiety, the factors that had significant influence on depression were CPDI(𝛽=.230, p=.000), and K-ANX(𝛽=.472, p=.000). Other factors such as CPDI(𝛽=.276, p=.000), EDAS(𝛽=-.127, p=.019) and K-DEP(𝛽=.482, p=.000) were analyzed to have significant effects on anxiety. Therefore, the results of this study are thought to be meaningful as basic data that can be used to establish educational and counseling activities that help university students adjust to society and academically in the COVID-19 situation.

Students' Responses and Self-understanding in Liberal Arts and Personality Class (교양과 인성 수업에 나타난 학생들의 반응과 자기 이해)

  • Park, Joo Eun;Park, Sung Hae
    • The Journal of the Convergence on Culture Technology
    • /
    • v.8 no.4
    • /
    • pp.289-296
    • /
    • 2022
  • The purpose of this study was to examine the students' responses and self-understanding in the liberal arts and personality class, one of the compulsory liberal arts subjects at S University. The results of the study are as follows. First, the degree of influence on students' positive change in this class was higher than normal using a five-step Likert scale. In particular, as a result of the film discussion conducted by the researcher, satisfaction was very high. Second, as a result of picture test analysis, changes in coping ability through stress and resource scales were seen in the students, and it was an opportunity for students to understand themselves by looking into their minds. This study presented example of classes that can cultivate students' personality through literature, art, and video, and cultivate their qualities as global citizens, such as responsibility, leadership, cooperation, consideration, communication, and empathy, through discussion.

In silico genome wide identification and expression analysis of the WUSCHEL-related homeobox gene family in Medicago sativa

  • Yang, Tianhui;Gao, Ting;Wang, Chuang;Wang, Xiaochun;Chen, Caijin;Tian, Mei;Yang, Weidi
    • Genomics & Informatics
    • /
    • v.20 no.2
    • /
    • pp.19.1-19.15
    • /
    • 2022
  • Alfalfa (Medicago sativa) is an important food and feed crop which rich in mineral sources. The WUSCHEL-related homeobox (WOX) gene family plays important roles in plant development and identification of putative gene families, their structure, and potential functions is a primary step for not only understanding the genetic mechanisms behind various biological process but also for genetic improvement. A variety of computational tools, including MAFFT, HMMER, hidden Markov models, Pfam, SMART, MEGA, ProtTest, BLASTn, and BRAD, among others, were used. We identified 34 MsWOX genes based on a systematic analysis of the alfalfa plant genome spread in eight chromosomes. This is an expansion of the gene family which we attribute to observed chromosomal duplications. Sequence alignment analysis revealed 61 conserved proteins containing a homeodomain. Phylogenetic study sung reveal five evolutionary clades with 15 motif distributions. Gene structure analysis reveals various exon, intron, and untranslated structures which are consistent in genes from similar clades. Functional analysis prediction of promoter regions reveals various transcription binding sites containing key growth, development, and stress-responsive transcription factor families such as MYB, ERF, AP2, and NAC which are spread across the genes. Most of the genes are predicted to be in the nucleus. Also, there are duplication events in some genes which explain the expansion of the family. The present research provides a clue on the potential roles of MsWOX family genes that will be useful for further understanding their functional roles in alfalfa plants.

Angelica keiskei Improved Beta-amyloid-induced Memory Deficiency of Alzheimer's Disease (아밀로이드 베타로 유발한 알츠하이머병 모델에서 신선초의 기억력 개선 효과)

  • Lee, Jihye;Kim, Hye-Jeong;Kim, Dong-Hyun;Shin, Bum Young;Jung, Ji Wook
    • The Korea Journal of Herbology
    • /
    • v.34 no.3
    • /
    • pp.1-7
    • /
    • 2019
  • Objectives : Amyloid ${\beta}(A{\beta})$ could induce cognitive deficits through oxidative stress, inflammation, and neuron death in Alzheimer's disease (AD). This study was investigated the effect of Angelica keiskei KOIDZUMI (AK) on memory in $A{\beta}$-induced an AD model. Methods : AK was extracted uses 70% ethanol solvent. Total polyphenol and flavonoids content were obtained by the Folin-Ciocalteu and the Ethylene glycol colorimetric methods, respectively. The antioxidant activities were assessed through free radical scavenging assays using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazolin-6-sulfonic acid) (ABTS) methods. Intracerebroventrical (i.c.v) injection of $A{\beta}$ 1-42 was used to induce AD in male ICR mice, followed by administrations of 5, 10 or 20 mg/kg AK on a daily. Animals were subjected to short and long term memory behavior in Y-maze and passive avoidance test. Results : The total polyphenol and flavonoids contents of the AK extract were $88.73{\pm}6.36mg$ gallic acid equivalent/g, $84.21{\pm}5.04mg$ rutin equivalent/g, respectively. The assays of DPPH and ABTS revealed that AK extract in treated concentrations (31.25, 62.5, 125, 250, 500, $1000{\mu}g/m{\ell}$) increased antioxidant activity in a dose-dependent manner. Oral administration of AK extract significantly reversed the $A{\beta}$ 1-42-induced decreasing of the spontaneous alternation in the Y-maze test and $A{\beta}$ 1-42-induced shorting of the step-through latency in the passive avoidance test. Conclusions : The findings suggest that AK indicated the antioxidant protective effects against $A{\beta}$-induced memory deficits, and therefore a potential lead natural therapeutic drug or agent for AD.

Comparative Study on Facial Skin Conditions Before and After Washing Face with Placenta CP Soap (자하거 저온숙성비누의 세안전·후 안면피부상태 비교연구)

  • Jin Suk Koo
    • The Korea Journal of Herbology
    • /
    • v.38 no.2
    • /
    • pp.35-41
    • /
    • 2023
  • Objectives : Washing face is the first step in skin beauty and health. I wanted to study the cleansing effect by using Placenta cp (cold process) soap. The skin condition is greatly influenced by the external environment such as lifestyle, drinking, smoking, and stress etc. I tried to measure the skin change state without environmental factors. Methods : In order to examine the effect before and after washing face under the same conditions, the same water and towel were used in the same place. The skin test was performed before and 10 minutes after washing. As a control group, a case of washing with water and foam cleanser. I compared and analyzed three cases: water washing, F/C (foam cleanser) washing, and Placenta cp soap washing. Results : In the case of water washing, it was significantly reduced in pores and increased in facial temperature. In the case of F/C washing, the facial temperature was significantly increased, but the decrease in moisture. In the case of washing with Placenta cp soap, significant reductions in T-zone and U-zone oil content, reduction in pore size, and increase in facial skin temperature were observed. Conclusion : In the case of Placenta cp soap, it is thought to be suitable for oily skin type, because of significant decrease in T-zone and U-zone oil content. It is thought to have the effect of increasing blood circulation in the facial skin and to reduce pores for oily skin types.

Analysis of Laterally Loaded Pile-Bent Structure with Varying Cross-sectional Area (변단면 파일벤트 구조의 수평거동 분석)

  • Jeong, Sang-Seom;Sung, Chul-Gyu;Ko, Jun-Young;Kim, Soo-Il
    • Journal of the Korean Geotechnical Society
    • /
    • v.25 no.4
    • /
    • pp.69-75
    • /
    • 2009
  • The load distribution and deformation of pile-bent structures are investigated using a numerical study. A numerical analysis that takes into account the effects of varying cross-sectional area was performed for different pier diameters, loading steps, and soil conditions. Through the comparison study, it is shown that the location of maximum bending moment is almost the same per each loading step, regardless of varying cross-sections. However, the member force (i.e., stress of pile material) has the largest value at the ground surface when the cross-section is changed. Based on the results obtained, it is found that the location of maximum member force influences highly the behavior of pile-bent structure with varying cross-sections for repair works.

The Acetylation-based synthesis of 3,3',4',5,5',7-hexaacetate myricetin and evaluation of its anti-inflammatory activities in lipopolysaccharide-induced RAW264.7 mouse macrophage cells

  • Kristina Lama;Hyehyun Hong;Tae-Jin Park;Jin-Soo Park;Won-Jae Chi;Seung-Young Kim
    • Journal of Applied Biological Chemistry
    • /
    • v.66
    • /
    • pp.29-38
    • /
    • 2023
  • Recent studies have highlighted the link between diseases and inflammation across our lifespan. Our sedentary lifestyle, high-calorie diet, chronic stress, chronic infections, and exposure to pollutants and xenobiotics, collectively intensify the course and recurrence of infections and inflammation in our bodies, promoting the prevalence of chronic diseases and aging. Given such phenomena and considering additional factors such as the frequency of prescription, and easy access to over-the-counter drugs, the need for anti-inflammatory therapeutics is ever-increasing. However, the readily available anti-inflammatory treatment option comes with a greater risk of side effects or high cost (biologics). Therefore in this growing competition of discovering and developing new potent anti-inflammatory drugs, we focused on utilizing the established knowledge of traditional medicine to find lead compounds. Since lead optimization is an indispensable step toward drug development, we applied this concept for the production of potent anti-inflammatory compounds achieved by structural modification of flavonoids. The derivative obtained through acetylation of myricetin, 3,3',4',5,5',7-hexaacetate myricetin, showed a greater inhibitory effect in the production of pro-inflammatory mediators such as nitric oxide, Prostaglandin E2, and pro-inflammatory cytokines like interleukin-6, interleukin1β, in lipopolysaccharide-stimulated RAW264.7 mouse macrophage cells compared to myricetin. The increased potency of inhibition was in conjunction with an increased inhibitory effect on inducible nitric oxide synthase and cyclooxygenase-2 proteins. Through such measures, this study supports lead optimization for well-established lead compounds from traditional medicine using a simpler and greener chemistry approach for the purpose of designing and developing potent anti-inflammatory therapeutics with possibly fewer side effects and increased bioavailability.