Simultaneous fabrication of line and dot dual nanopatterns using miktoarm block copolymer with photocleavable linker

Block copolymers with various nanodomains, such as spheres, cylinders, and lamellae, have received attention for their applicability to nanolithography. However, those microdomains are determined by the volume fraction of one block. Meanwhile, nanopatterns with multiple shapes are required for the next-generation nanolithography. Although various methods have been reported to achieve dual nanopatterns, all the methods need sophisticated processes using E-beam. Here, we synthesized a miktoarm block copolymer capable of cleavage of one block by ultraviolet. Original cylindrical nanodomains of synthesized block copolymer were successfully transformed to lamellar nanodomains due to the change of molecular architecture by ultraviolet. We fabricated dual nanopatterns consisting of dots and lines at desired regions on a single substrate. We also prepared dual nanopatterns utilizing another phase transformation from spheres to cylinders in a block copolymer with higher interaction parameter. Since our concept has versatility to any block copolymer, it could be employed as next-generation nanolithography.112Ysciescopu

Applicability of Concrete–Steel Composite Piles for Offshore Wind Foundations

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Factors That Affect Suicidal Attempt Risk Among Korean Elderly Adults: A Path Analysis

Objectives: Among the Korean elderly (those 65 years of age and older), the suicide rate is 80.3/100 000 people, which is ten times higher than the Organization for Economic Cooperation and Development average. Because South Korea is rapidly becoming an aging population, this high elderly suicidal rate will only get worse. Although the size of the elderly suicide problem is quite large, previous research in South Korea has surveyed restricted areas and not the entire country. Even though the factors that affect elderly suicide are complicated, there has been little research into these influencing factors. Thus, this research uses the national survey data (Community Health Survey) that was obtained in 2009. Additionally, we analyze factors affecting elderly suicidal ideation and attempts as well as the paths of these effects. Methods: Community Health Survey data obtained by the Korea Centers for Disease Control and Prevention in 2009 was used for this study. We additionally examined the factors that affect suicide with chi-squared tests, t-tests, Pearson’s correlation test, and path analysis. Results: Depressive symptoms and suicidal ideation are the only factors that directly affect suicidal attempts. Demographic, behavioral, and physical activity factors have indirect effects on suicidal attempts. Conclusions: Depression has the strongest influence on suicidal ideation and attempts. Demographic, behavioral, and physical activity factors affect suicidal attempts mostly through depressive symptoms. In addition, there is a path that suggests that demographic, behavioral, and physical activity factors affect suicidal attempts not through depression symptoms but only through suicidal ideation. This means that the elderly who do not have depression symptoms attempt suicide according to their own situations and characteristics

Radiation Hardness Test of a Silicon Detector under Radiation Dose Rate of Nuclear Power Plant for In-Containment Coolant Leakage Detection System

An influence evaluation by background radiation on a silicon detector, which will be used to detect a coolant leakage, and installed in a containment building of a nuclear power plant, was performed and the result was discussed. The detector that consists of a silicon sensor and preamplifier mounted in a shielding structure which composed of a 5 cm lead cylinder will be installed in an annulus zone that is influenced by background radiation (neutron and gamma ray) from an operation of a nuclear reactor. Absorbed dose rates on a silicon sensor and preamplifier were calculated as 2.15 mGy/hr and 1.05 mGy/hr, respectively, by Monte Carlo N-Particle (MCNP) simulation. Data of background radiation had referred to a Final Safety Analysis Report (FSAR) of a nuclear power plant in the Republic of Korea. A silicon sensor and preamplifier were irradiated by a Co60 gamma radiation source equipped in a facility of Korea Atomic Energy Research Institute Advanced Radiation Technology Institute (KAERI ARTI) of the Republic of Korea. A Po-210 alpha source was used as a check source to evaluate a state of a function of the detector during gamma irradiation. Absorbed dose rates were about 22.92 mGy/hr and 6.6 mGy/hr on silicon sensor and preamplifier, respectively. Before and during gamma irradiation, a count rates from the check source wasn`t changed (from 18.4 cps to 18.4±0.2 cps after irradiation), and any degradations of function also weren`t observed. Even more harsh condition than calculated dose rates referred by the condition of background radiation of in-containment, the silicon detector maintained the ability of function of charged particles detection. Based on the result, it has been demonstrated that a silicon detector is a suitable detector for detecting charged particles from a leaked coolant even during interfered by the background radiation of a primary system of a nuclear power plant

Applicability of Concrete–Steel Composite Piles for Offshore Wind Foundations

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Photo-Responsive Order-Order phase transition of Miktoarm Block Copolymer Containing UV cleavable linker

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Photo-Induced Order-to-Order phase Transition of Block Copolymer to Fabricate Dual-Pattern Substrate via hydrogen bonding

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Perpendicularly Oriented Nanostructures of Sar-Shaped PMMA-b-PS Thin Film

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