• Steel and Composite Structures
• /
• v.36 no.1
• /
• pp.63-74
• /
• 2020

The present research investigates post-buckling behavior of geometrically imperfect tapered curved micro-panels made of graphene oxide powder (GOP) reinforced composite. Micro-scale effects on the panel structure have been included based on strain gradient elasticity. Micro-panel is considered to be tapered based on thickness variation along longitudinal direction. Weight fractions of uniformly and linearly distributed GOPs are included in material properties based on Halpin-Tsai homogenization scheme considering. Post-buckling curves have been determined based on both perfect and imperfect micro-panel assumptions. It is found that post-buckling curves are varying with the changes of GOPs weight fraction, geometric imperfection, GOP distribution type, variable thickness parameters, panel curvature radius and strain gradient.

• Acta Via Serica
• /
• v.5 no.1
• /
• pp.1-22
• /
• 2020

The paper discusses how the new EU Strategy towards Central Asia issued in May 2019 might be analyzed through the lens of the intensely debated transformations from the liberal to a post-liberal international order. The author claims that the EU's normative power is transforming from the post-Cold War predominantly liberal/ value-based approach, with democracy and human rights at its core, to a set of more technical tools and principles of good governance and effective management of public administration. The paper problematizes a nexus between the dynamics of the EU's nascent post-liberalism and the geopolitical challenges of the EU's growing engagement with illiberal regimes, focuses on direct encounters between the post-liberal EU and the illiberal elites in Central Asia, and seeks to find out the impact of these connections upon the EU's international subjectivity. In this context geopolitical dimensions of EU foreign and security policies, along with the specificity of the EU's geopolitical actorship in Central Asia, are discussed.

• Medical Lasers
• /
• v.9 no.2
• /
• pp.187-189
• /
• 2020

Cold atmospheric plasma (CAP) is a material that generates free radicals through the ionization of air. Despite the application in various medical fields, the efficacy and safety of CAP on post-inflammatory hyperpigmentation due to atopic dermatitis have not been reported. Herein, we report the improvement in post-inflammatory hyperpigmentation of atopic dermatitis, after CAP treatment of three sessions weekly, 10 minutes per session. We examined the clinical severity indexes before and after treatment, including the Investigator's Global Assessment, modified Atopic Dermatitis Antecubital Severity, Eczema Area and Severity Index, and pruritus visual analogue scores. Our results indicate that CAP alleviates the post-inflammatory hyperpigmentation and clinical severity of atopic dermatitis, and effectively improves the atopic skin lesion without severe safety issues. We believe that the previously reported anti-bacterial effects and production of interleukin-6 after CAP treatment are probably responsible for the underlying mechanisms leading to clinical improvement.

• Advances in nano research
• /
• v.8 no.3
• /
• pp.255-264
• /
• 2020

Buckling and post-buckling cases are often occurred in aorta artery because it affected by higher pressure. Also, its stability has a vital importance to humans and animals. The loss of stability in arteries may lead to arterial tortuosity and kinking. In this paper, post-buckling analysis of aorta artery is investigated under axial compression loads on the basis of Euler-Bernoulli beam theory by using finite element method. It is known that post-buckling problems are geometrically nonlinear problems. In the geometrically nonlinear model, the Von Karman nonlinear kinematic relationship is employed. Two types of support conditions for the aorta artery are considered. The considered non-linear problem is solved by using incremental displacement-based finite element method in conjunction with Newton-Raphson iteration method. The aorta artery is modeled as a cylindrical tube with different average diameters. In the numerical results, the effects of the geometry parameters of aorta artery on the post-buckling case are investigated in detail. Nonlinear deflections and critical buckling loads are obtained and discussed on the post-buckling case.

• Advances in nano research
• /
• v.9 no.3
• /
• pp.147-156
• /
• 2020

This research is related to nonlinear stability analysis of advanced microbeams reinforced by Graphene Platelets (GPLs) considering generic geometrical imperfections and thermal loading effect. Uniform, linear and nonlinear distributions of GPLs in transverse direction have been considered. Imperfection sensitivity of post-bucking behaviors of the microbeam to different kinds of geometric imperfections have been examined. Geometric imperfection is first considered to be identical as the first buckling mode, then a generic function is employed to consider sine-type, local-type and global-type imperfectness. Modified couple stress theory is adopted to incorporate size-dependent behaviors of the beam at micro scale. The post-buckling problem is solved analytically to derive load-amplitude curves. It is shown that post-buckling behavior of microbeam is dependent on the type geometric imperfection and its magnitude. Also, post-buckling load can be enhanced by adding more GPLs or selecting a suitable distribution for GPLs.

• Health Policy and Management
• /
• v.30 no.2
• /
• pp.139-141
• /
• 2020

Coronavirus disease 2019 (COVID-19) is currently in progress. Although it is difficult to predict the end of currently increasing COVID-19, it is expected to last for a long time. The COVID-19 is making a lot of changes. Due to physical distancing and living distancing, non-contacts such as wearing facial masks, online lectures, online medical services, telecommuting, and telemarketing are becoming common. In the era of post-COVID-19, online and offline will coexist. Many countries following China's lockdown strategy, which is agreed with the World Health Organization, should be changed to Taiwan's facial mask strategy for reducing the economic problems. The prolonging COVID-19 will add to the economic difficulties, and the US-China confrontation will be difficult to rebound the global economy. COVID-19, such as plaque, smallpox, and Spanish influenza, will be a historical momentum. How to respond to the crisis of COVID-19 and post-COVID-19 will determine the future of the world and Korea.

• Computers and Concrete
• /
• v.26 no.1
• /
• pp.21-30
• /
• 2020

Buckling and post-buckling behaviors of geometrically imperfect annular sector plates made from nanoparticle reinforced composites have been investigated. Two types of nanoparticles are considered including graphene oxide powders (GOPs) and silicone oxide (SiO₂). Nanoparticles are considered to have uniform and functionally graded distributions within the matrix and the material properties are derived using Halpin-Tsai procedure. Annular sector plate is formulated based upon thin shell theory considering geometric nonlinearity and imperfectness. After solving the governing equations via Galerkin's technique, it is showed that the post-buckling curves of annular sector plates rely on the geometric imperfection, nanoparticle type, amount of nanoparticles, sector inner/outer radius and sector open angle.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.24 no.4
• /
• pp.66-72
• /
• 2020

In this report, the post-curing and chemical aging ratio of propellants are described according to several aluminum contents. Under the same curing conditions, it was confirmed that the post-curing period of propellant having the aluminum content of 18 wt% was longer than the propellant having the 2 wt% of aluminum. On the other hand, in the chemical aging ratio analysis including post-curing, the propellant having the 18 wt% of aluminum was confirmed that the chemical aging proceeds slowly compared to the propellant having an aluminum content of 2 wt%.

• Journal of Environmental Policy
• /
• v.14 no.4
• /
• pp.3-21
• /
• 2015

This paper attempts to determine the most reasonable and agreeable option for new MRV framework in Post-2020 Climate Regime as well as to develop South Korea strategies to reflect our national circumstances and capacities appropriately. The options for MRV framework considered here are 1) Dual MRV and 2) Unified MRV. We reached the conclusion that the Unified MRV framework may be the most reasonable option in the 2015 agreement in line with the objectives of MRV. To this end, it is essential to develop effective stepwise strategies consisted of: 1) reaching a consensus internally on the Unified MRV framework, 2) developing detailed procedures and methodologies to make the major elements of the Unified MRV framework understandable and predictable, 3) delivering an overview and blueprint to make sure of the flexibility of the Unified MRV framework to reflect the Parties' capacities and national circumstances, 4) ensuring the financial and technical support schemes for developing countries to improve the capacity-buildings of MRV, and 5) developing a realistic road map to successfully implement the Unified MRV scheme within the required time frame. Korea, as a rational mediator between developed and developing countries, should play a leading role in reaching post-2020 agreement.

• Child Health Nursing Research
• /
• v.26 no.2
• /
• pp.267-276
• /
• 2020

Purpose: Caring for a vulnerable premature baby is a challenging task, but some mothers experience growth through that process. The purpose of this study was to investigate the factors influencing post-traumatic growth in mothers with premature infants admitted to the neonatal intensive care unit. Methods: A correlational research design was used and 105 mothers of premature infants were recruited from an online community. Data were collected from January 15 to January 25, 2019. Post-traumatic growth was measured using the Korean version of the Posttraumatic Growth Inventory. Data were analyzed using descriptive statistics, the t-test, analysis of variance, the Scheffé test, Pearson correlation coefficients, and hierarchical multiple regression. Results: The final model developed in this study explained 45.5% of post-traumatic growth (F=13.66, p<.001). Resilience (β=.54, p<.001) was the strongest predictor of post-traumatic growth, followed by the age of the mother when giving birth (β=.17, p=.028) and current employment status (β=.17, p=.049). Conclusion: For mother with premature infants to grow psychologically after their experience, it may be needed to support them to develop and strengthen their resilience through either education or their own support network.