This study replicates and extends Lee-Ellis’s (2009) work by examining how different scoring methods affect the measurement characteristics of a Korean C-test. Thirty-six learners of Korean as a second language completed a five-passage C-test. Their responses were scored using Partial Credit Modeling, dichotomous item-by-item scoring, and dichotomous morpheme- by-morpheme scoring. Rasch analysis was conducted to compare reliability, person separation, item fit, and interpretability across these scoring approaches. The study also treated each text passage as a “super-item” to evaluate proficiency interpretation at the passage level. All three scoring methods demonstrated high reliability (above .97) and yielded highly correlated proficiency estimates. No single scoring method proved significantly superior in reliability, separation, or model fit. At the super-item level, the passages showed a narrow spread of difficulty indicating limited coverage of proficiency levels. These findings suggest that fine-grained scoring alone cannot compensate for limited test scope. To enhance the diagnostic value and level-referenced interpretation of C-tests, careful selection of text passages spanning a broader proficiency spectrum is essential.

Self-assembled organic layers containing various functional groups between graphene layers were examined as gas barrier films. The formation of well-defined self-assembled layers of functionalized alkane molecules on graphene was confirmed by scanning tunneling microscopy (STM). The roles of these organic layers as gas barrier films could be quantitatively deduced by comparing their water vapor transmission rate (WVTR). The formation of self-assembled layers dramatically improved gas barrier properties by primarily blocking defects and gas molecule pathways. For functionalized alkanes containing hydrophilic groups, more enhanced gas barrier properties were observed compared to those with hydrophobic groups. These results clearly indicate that the primary role of the organic layers in gas barrier films is to block defects and the pathways of water molecules, with a secondary role of delaying the movement of water molecules through hydrogen bonding interactions.

In recent years, high-entropy alloys (HEAs) have attracted considerable attention in materials engineering due to their unique phase stability and mechanical properties compared to conventional alloys. Since the inception of HEAs, CoCrFeMnNi alloys have been widely investigated due to their outstanding strength and fracture toughness at cryogenic temperatures. However, their lower yield strength at room temperature limits their structural applications. The mechanical properties of HEAs are greatly influenced by their processing methods and microstructural features. Unlike traditional melting techniques, powder metallurgy (PM) provides a unique opportunity to produce HEAs with nanocrystalline structures and uniform compositions. The current review explores recent advances in optimizing the microstructural characteristics in CoCrFeMnNi HEAs by using PM techniques to improve mechanical performance. The most promising strategies include grain refinement, dispersion strengthening, and the development of heterogeneous microstructures (e.g., harmonic, bimodal, and multi-metal lamellar structures). Thermomechanical treatments along with additive manufacturing techniques are also summarized. Additionally, the review addresses current challenges and suggests future research directions for designing advanced HEAs through PM techniques.