• Animal Bioscience
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• 제34권3_spc호
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• pp.443-448
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• 2021

Objective: Astaxanthin is a natural super antioxidant. The present study was carried out to investigate the effect of astaxanthin rich Phaffia rhodozyma (PR) supplementation in diets on laying production performance, egg quality, antioxidant defenses and immune defenses in laying hens. Methods: A total of five hundred and twelve 60-week-old Lohmann Brown laying hens (2,243±12 g) were randomly assigned to four groups, each including 4 replicates with 32 birds per replicate. Astaxanthin rich PR was added to corn-soybean meal diets to produce experimental diets containing 0 (Control), 800 mg/kg, 1,200 mg/kg, and 1,600 mg/kg PR, respectively. The astaxanthin content in the diet was 0.96 mg/kg, 1.44 mg/kg and 1.92 mg/kg respectively. Results: Results showed that dietary PR supplementation tended to increase daily feed intake (p = 0.0512). There was no effect of astaxanthin rich PR on Haugh units, albumen height, egg shape index, eggshell strength, and eggshell thickness at weeks 6 (p>0.05). However, egg yolk color was significantly improved (p<0.05). In addition, astaxanthin rich PR supplementation significantly increased serum glutathione peroxidase and superoxide dismutase activity (p<0.05), increased serum immunoglobulin G content (p<0.05), and reduced malondialdehyde content (p<0.05) in laying hens. Conclusion: In conclusion, astaxanthin rich PR can improve the color of egg yolk, enhance the antioxidant defenses, and regulate the immune function.

• 한국융합학회논문지
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• 제12권2호
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• pp.185-191
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• 2021

본 자동차 실린더 블록 주조시 실린더 보어 내에서 발생하는 열로부터 구조적 변형을 방지하는데 필요한 워터 자켓 코어용 주물사의 특성을 분석하였다. 샌드 코어의 특성평가를 위하여 인장강도 시험기, 입도 지수(AFS-GFN), 광학현미경을 사용하였다. 주물사의 SiO2 함량이 높으면 고온팽창에 의한 치수 불량, 베이닝 불량이 발생하며, 너무 낮으면 코어 파손, 기포, 화학적 소착 등이 발생하였다. 입도 지수와 입형이 코어강도와 레진 소비량에 영향을 미치고, 이로 인한 불량 유형 변화가 발생하였다. 건조사가 염분이 높을수록 코어 강도는 감소하며, 알칼리성일수록 코어 강도가 감소하였다. 레진 함량 1.6~1.8%에서 1시간 경화 이후에 코어 강도 증가는 대략 최대를 보였다.

• International Journal of Knowledge Content Development & Technology
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• 제11권4호
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• pp.101-111
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• 2021

The world is going through the most unprecedented time with the outbreak of novel Coronavirus disease (COVID-19), which has become a threat to millions. A Coronavirus is a group of viruses that cause a variety of diseases in mammals and birds leading to a range of illnesses in humans including common cold and more severe forms like severe acute respiratory syndrome Coronavirus (SARS-CoV), Middle East respiratory syndrome Coronavirus (MERS-CoV) and COVID-19, which are life-threatening. The virus gets its name from its shape which takes the form of a crown with protrusions around it. In December 2019, a pneumonia outbreak was reported in the Wuhan City of China, which was later traced to a novel strain of Coronavirus and termed as Novel COVID-19. It typically causes flu-like symptoms including fever, cough and shortness of breath and is transmitted through human-to-human and there is no cure for it till now. Thus, this bibliometric study has been carried out to analyze the research progress in Coronavirus and literature published during a period of 30 years (1989-2019). Data for the study were fetched from Web of Science(WoS) multidisciplinary database and the publication trends in terms of total articles, productive countries, institutions, journals, productive authors, most cited articles and authors, etc have been analyzed. In total, 4917 articles were retrieved; these were from 711 sources and were contributed by 14442 authors. The collaboration index was 3.11, which clearly indicates that there has been a lot of collaboration in this field. The most preferred journal for the study period was "Journal of Virology" and the maximum contribution has been from the University of Hong Kong.

• Wind and Structures
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• 제34권2호
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• pp.185-197
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• 2022

This study aimed to analyze the wind-induced mechanical energy (WME) of a proposed super high-rise and long-span transmission tower-line system (SHLTTS), which, in 2021, is the tallest tower-line system with the longest span. Anew index - the WME, accounting for the wind-induced vibration behavior of the whole system rather than the local part, was first proposed. The occurrence of the maximum WME for a transmission tower, with or without conductors, under synoptic winds, was analyzed, and the corresponding formulae were derived based on stochastic vibration theory. Some calculation data, such as the drag coefficient, dynamic parameters, windshielding areas, mass, calculation point coordinates, mode shape and influence function, derived from wind tunnel testing on reducedscale models and finite element software were used in calculating the maximum WME of the transmission tower under three cases. Then, the influence of conductors, wind speed, gradient wind height and wind yaw angle on WME components and the energy transfer relationship between substructures (transmission tower and conductor) were analyzed. The study showed that the presence of conductors increases the WME of transmission towers and changes the proportion of the mean component (MC), background component (BC) and resonant component (RC) for WME; The RC of WME is more susceptible to the wind speed change. Affected by the gradient wind height, the WME components decrease. With the RC decreasing the fastest and the MC decreasing the slowest; The WME reaches the its maximum value at the wind yaw angle of 30°. Due to the influence of three factors, namely: the long span of the conductors, the gradient wind height and the complex geometrical profile, it is important that the tower-line coupling effect, the potential for fatigue damage and the most unfavorable wind yaw angle should be given particular attention in the wind-resistant design of SHLTTSs

• Advances in concrete construction
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• 제14권3호
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• pp.169-183
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• 2022

In this article, vibrational behavior and wave propagation characteristics in (FG) functionally graded plates resting on Kerr foundation with three parameters is studied using a 2D dimensional (HSDT) higher shear deformation theory. The new 2D higher shear deformation theory has only four variables in field's displacement, which means has few numbers of unknowns compared with others theories. The shape function used in this theory satisfies the nullity conditions of the shear stresses on the two surfaces of the FG plate without using shear correction factors. The FG plates are considered to rest on the Kerr layer, which is interconnected with a Pasternak-Kerr shear layer. The FG plate is materially inhomogeneous. The material properties are supposed to vary smoothly according to the thickness of the plate by a Voigt's power mixing law of the volume fraction. The equations of motion due to the dynamics of the plate resting on a three-parameter foundation are derived using the principle of minimization of energies; which are then solved analytically by the Navier technique to find the vibratory characteristics of a simply supported plate, and the wave propagation results are derived by using the dispersion relations. Perceivable numerical results are fulfilled to evaluate the vibratory and the wave propagation characteristics in functionally graded plates and some parameters such wave number, thickness ratio, power index and foundation parameters are discussed in detail.

• 한국작물학회지
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• 제27권1호
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• pp.87-93
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• 1982

담배 황색종 품종인 SC72와 Hicks를 교배하여 그 $F_1$잡종식물의 약으로부터 유기한 반수체식물을 배가시켜 얻은 30계통의 10개 양적형질에 대한 변이, 유전력, 유전상관 및 경로계수의 분석에 의하여 각형질들의 유전현상을 본바 그 결과를 요약하면 다음과 같다. 1. 교배친간 각 형질의 변이폭은 1.5~37.8%인데 비하여 반수체배가계통간에는 19.6%~100.1%로 현저히 크게 나타났고 평균치에 있어서는 교배친에 비하여 반수체배가계통들은 nicotine, 수확엽수 및 엽장폭비가 증가하는 경향이나 그외 특성들은 저하되는 경향이었다. 2. 유전력은 개화일수 및 수확엽수는 높게, reducing sugar, kg당 가격 및 수량은 낮게, 그외 형질들은 중간치를 나타내었다. 3. 유전상관의 값은 표현형상관보다 그 값이 다소 높은 경향이었고, 수량은 kg당 가격, 엽폭, 수확엽수 및 reducing sugar와는 정의 상관이었고, nicotine은 엽장폭비를 제외한 타형질과는 부의 상관을 나타내었다. 4. 수량과 각형질간의 경로계수를 분석한 결과 수확엽수와 엽폭이 수량에 미치는 직접효과가 컸으며, 간접효과는 개화일수와 초장이 크게 나타났다.

• Structural Engineering and Mechanics
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• 제86권1호
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• pp.1-16
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• 2023

The free vibration of temperature-dependent functionally graded plates (FGPs) resting on a viscoelastic foundation is investigated in this paper using a newly developed simple first-order shear deformation theory (FSDT). Unlike other first order shear deformation (FSDT) theories, the proposed model contains only four variables' unknowns in which the transverse shear stress and strain follow a parabolic distribution along the plates' thickness, and they vanish at the top and bottom surfaces of the plate by considering a new shape function. For this reason, the present theory requires no shear correction factor. Linear steady-state thermal loads and power-law material properties are supposed to be graded across the plate's thickness. Uniform, linear, non-linear, and sinusoidal thermal rises are applied at the two surfaces for simply supported FGP. Hamilton's principle and Navier's approach are utilized to develop motion equations and analytical solutions. The developed theory shows progress in predicting the frequencies of temperature-dependent FGP. Numerical research is conducted to explain the effect of the power law index, temperature fields, and damping coefficient on the dynamic behavior of temperature-dependent FGPs. It can be concluded that the equation and transformation of the proposed model are as simple as the FSDT.

• Structural Engineering and Mechanics
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• 제86권2호
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• pp.167-180
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• 2023

This work applies a four-known quasi-3D shear deformation theory to investigate the bending behavior of a functionally graded plate resting on a viscoelastic foundation and subjected to hygro-thermo-mechanical loading. The theory utilizes a hyperbolic shape function to predict the transverse shear stress, and the transverse stretching effect of the plate is considered. The principle of virtual displacement is applied to obtain the governing differential equations, and the Navier method, which comprises an exponential term, is used to obtain the solution. Novel to the current study, the impact of the viscoelastic foundation model, which includes a time-dependent viscosity parameter in addition to Winkler's and Pasternak parameters, is carefully investigated. Numerical examples are presented to validate the theory. A parametric study is conducted to study the effect of the damping coefficient, the linear and nonlinear loadings, the power-law index, and the plate width-tothickness ratio on the plate bending response. The results show that the presence of the viscoelastic foundation causes an 18% decrease in the plate deflection and about a 10% increase in transverse shear stresses under both linear and nonlinear loading conditions. Additionally, nonlinear loading causes a one-and-a-half times increase in horizontal stresses and a nearly two-times increase in normal transverse stresses compared to linear loading. Based on the article's findings, it can be concluded that the viscosity effect plays a significant role in the bending response of plates in hygrothermal environments. Hence it shall be considered in the design.

• The Korean Journal of Pain
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• 제36권2호
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• pp.208-215
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• 2023

Background: To evaluate the feasibility, inter-reader reliability, and intra-reader reliability for various morphological features reported to be related to iliotibial band friction syndrome (ITBFS) on knee magnetic resonance imaging (MRI). Methods: A total of 145 patients with a clinical diagnosis and knee MRI findings consistent with ITBFS were included in the "study group" and 232 patients without knee pathology on both physical examination and MRI were included in the "control group". Various morphologic features on knee MRI were assessed including the patella shape, patella height, lateral epicondyle anterior-posterior (AP) width, lateral epicondyle height, ITB diameter (ITB-d), and ITB area (ITB-a). Results: Patients in the study group had significantly higher lateral epicondyle height (13.9 mm vs. 12.92 mm, P = 0.003), ITB-d (2.9 mm vs. 2.0 mm, P = 0.022), and ITB-a (38.5 mm² vs. 23.8 mm², P < 0.001) than the control group. ITB-a showed higher area under the curve index (0.849 with 74.1% sensitivity and 72.4% specificity at a 30.3 mm² cutoff) than ITB-d (0.710 with 70.8% sensitivity and 61.2% specificity at 2.4 mm cutoff) and lateral epicondyle height (0.776 with 72.4% sensitivity and 67.8% specificity at 13.4 mm cutoff). However, only the inter-reader agreement for ITB-a (intraclass correlation coefficient = 0.65) was moderate, while the agreements for other morphologic features were good or excellent. Conclusions: Lateral epicondyle height seems to be a reliable and feasible morphologic feature for diagnosis of ITBFS.

• 대한토목학회논문집
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• 제29권3A호
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• pp.181-188
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• 2009

본 연구에서는 현수교의 합리적인 시공방안 결정 및 구조안전성 평가에 대한 기초자료를 제시하였다. 기 연구된 현수교의 해석모델 및 신뢰성이론을 바탕으로 초기형상해석, 자유진동해석, 시공변수를 고려한 시공단계해석 및 신뢰성해석 등을 수행 할 수 있는 수치해석프로그램을 개발하였다. 현수교의 시공방안은 보강형의 시공순서, 시공방향 및 주경간과 측경간의 동시 시공성 등의 다양한 시공변수를 고려하여 설정하였다. 시공방안에 따른 동적시공단계해석은 작성된 해석프로그램에 의해 수행하였으며 주요부재의 응답특성을 검토하여 각각의 시공방안에 대한 장 단점을 제시하였다. 시공단계별 구조신뢰성해석은 자연적 불확실성을 고려하여 신뢰성지수 및 파괴확률을 산정함으로써, 설정된 시공방안에 따른 현수교의 안전성을 정량적으로 평가하였다. 아울러, 인위적 불확실성을 고려하여 산정된 해석결과에 대해 재평가하였으며, 시공단계 위험성의 주요 퍼센트 분포를 빈도수 히스토그램을 이용하여 제시하였다.