Kaolins from an Al-rich clay deposit formed in volcanic tuff, southeastern Korea contain predominant dickite and quartz with accessory diaspore, pyrophyllite, alunite, illite, sulfides and calcite. Intergrowth of blocky crystals with thin ones within stacks suggests that blocky crystals gradually replaced thin ones within the same stacks. Numerous dickite plates with pseudo-hexagonal outline are placed in rows eventually forming a U-shaped stack and a vermiform stack. Individual crystals within the stack are of pseudo-hexagonal form and vermiform, accompanying slips across basal planes. The euhedral dickite with blocky habit has basal planes (001) and edge planes (110) perpendicular to each other, and it shows pseudo-hexagonal crystallites elongated in one direction. Fourier transform infrared spectra at OH-stretching and far-infrared regions show that the dickitic mass contains a small proportion of kaolinite or nacrite, indicating interstratification or at least mixtures of kaolin polytypes. The formation of mixtures of various polytypes that are of kaolinite-dickite, dickite and mixtures of dickite-nacrite could be attributed to hydrothermal processes ranging over a broad spectrum of temperature and fluid chemistry.

Waterproofing treatment is important for the preservation of smectite-rich rocks because of their shrinking and swelling properties. The effects of water repellents on the smectite structure and the water sorption of untreated and treated smectites were studied using X-ray diffraction. The hydrophobic Wacker BS 290 (around 100% silane/siloxane) does not prevent water from sorbing on the interlayer surface of smectite because the hydrophobic silane/siloxane is not intercalated into the interlayer space, but adsorbed onto the external surface of smectite. However, the hydrophilic Wacker BS 1001 (water-soluble emulsified silane/siloxane) prevents water from sorbing onto the interlayer surface beyond 33.3 wt.% because the hydrophobic part of the intercalated surfactant has a poor affinity for water. These results imply that water repellent containing a surfactant is suitable for smectite-rich rocks, but the expansion of smectite by intercalation of the surfactant is likely to influence volume change in smectite-rich rocks. This study notes that smectite within a rock can be one of the most important factors influencing the effectiveness of waterproof treatment. This study proposes that an intensive preliminary examination should be performed before applying water repellents to rocks, and furthermore, encourages development of new chemical reagents suitable for protecting smectite-rich rocks from moisture.

Objectives: The treatment of infected knee arthritis in patients with coexisting joint destruction, including superimposed advanced arthritis or chronic osteomyelitis, is challenging. We investigated the outcomes of 2-stage primary total knee arthroplasty (TKA) for evolutive infected arthritis with coexistent joint destruction. Methods: We retrospectively reviewed the cases of 50 patients from 5 hospitals who presented with infected arthritis of the knee and were treated with 2-stage TKA: debridement and antibiotic-loaded articulating cement spacer (ALCS) insertion as the first stage and TKA as the second stage. We recorded demographics, laboratory results, and radiographic findings including Kellgren-Lawrence classification (KL) for knee arthritis. Outcomes including infection eradication, knee range of motion (ROM), and patient-reported outcome measures were evaluated. Results: The patient cohort had a mean age of 71.8 years (range, 40–86); they were followed for an average of 4.1 years (range, 2.2–13.3). Also, 40 patients showed KL grade 4, whereas 10 patients showed grade 3. A pathogen was identified in 38 cases (73.1%); methicillin-resistant staphylococci infections (N = 16) and Candida spp infections (N = 7) were the 2 most common types. Constrained prostheses were used in 10 cases (20%). Stem augmentations were used in 15 cases (36.0%) and block augmentations were used in 8 cases (19.0%). One patient had recurrent infection after TKA, so the eradication rate was 98%. After 2-stage TKA, the mean knee ROM was 119.4° (range, 80°–140°) and the mean Knee Society (KS) knee score was 90.4, the average KS function score was 84.7, the average Hospital for Special Surgery (HSS) score was 87.2, and the average Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score was 16.7. The KS function scores (P = .029) and the WOMAC scores (P = .022) were significantly better in 17 patients who underwent ALCS insertion within 30 days of infection diagnosis compared to the other 33 patients. Conclusions: The 2-stage primary TKA for patients with infected knee arthritis with coexisting joint destruction showed satisfactory outcomes with a low infection recurrence. However, constrained prostheses or augmentation use may be necessary. Notably, some functional scores were better in the group that underwent ALCS insertion relatively early after the infection diagnosis.

A sediment core (14DH-C01) obtained from the mouth of Gomso Bay, on the west coast of South Korea, was used to obtain high-resolution palynomorph, grain-size, and 14C age data to investigate the Holocene sedimentary environment. The results indicated a transgressive depositional process with four stages controlled by sea-level change, as follows: river-dominated fluvial deposition from the early Holocene to 8.48 cal ka BP; tide-dominated tidal channel fill transgression from 8.48 to 8.08 cal ka BP; tide- to wave-dominated tidal channel fill transgression from 8.08 to 6.98 cal ka BP; and wave-dominated marine transgression from 6.98 cal ka BP to the present. Tidal channel filling was the primary mid-Holocene depositional process, accounting for the high sedimentation rate observed. The different hydrodynamics of the river-dominated, tide-dominated, tide- to wave-dominated, and wave-dominated processes following the changes in sea level may have controlled the transgressive depositional process. This transgressive sedimentary model differs from those of other large river mouth areas (e.g., the Changjiang River) since the mid-Holocene, perhaps resulting from the limited sediment supply in the study area.

We demonstrate the tungsten disulfide (WS2) thin film catalysts prepared by the sulfurization of vacuum deposited WO3 thin films for efficient hydrogen production with over 90% Faradaic efficiency. The 23-nm-thick WS2 thin film catalyst heterojunction with p-type silicon photocathode could exhibit a photocurrent density of 8.3 mA/cm2 at 0 V versus a reversible hydrogen electrode (RHE), a low onset potential of 0.2 V versus RHE when photocurrent density reaches −1 mA/cm2 and long-term stability over 10 h. The enhanced catalytic activities of WS2/p-Si photocathodes compared with the bare p-Si photocathode originate from a number of edge sites in the synthesized polycrystalline thin films, which could act as hydrogen evolution catalyst.

Background: Insomnia is a common psychiatric complaint among elderly individuals. This study investigates the prevalence and sociodemographic correlates of insomnia by considering a community sample of elderly individuals in South Korea.

Methods: A face-to-face household survey was conducted in five regions of South Korea from June 2008 to August 2008. Among a total of 3,074 individuals aged 65 years and over, 2,002 participants were interviewed. The presence of insomnia was defined as having at least one of four sleep complaints that included difficulty in initiating sleep (DIS), difficulty in maintaining sleep (DMS), early morning awakening (EMA), and non-restorative sleep (NRS) more than three times per week in the last month. The Restless Legs Syndrome (RLS) Questionnaire, a short form of the Geriatric Depression scale (GDS), and a medical review of systems were implemented.

Results: Insomnia was found in 29.2% of the participants. DIS, DMS, EMA, and NRS accounted for 19.4%, 21.7%, 19.6%, and 8.0% of the participants respectively. Insomnia accompanied by daytime consequences accounted for 17.1% of the participants. The participants who were females, had no education, lived alone, showed symptoms of RLS or depression, and had a lifetime history of physical illness were significantly more likely to report insomnia. The prevalence of DIS, DMS, EMA, or insomnia increased slightly with age, whereas that of NRS decreased slightly. The lifetime history of head trauma, hyperlipidemia, heart disease, anemia, or depression was significantly related to insomnia.

Conclusion: Sleep problems are common among elderly individuals and are closely related to their lifetime history of physical illness.

12Cr ODS steel samples were prepared by mechanical alloying of the metal powders with 20-30 nm Y2O3 particles followed by isostatic pressing, hot rolling and final heat treatment. Evolutions of oxide particles such as YTaO4 and YCrO3 after each fabrication step were investigated by using TEM with EDS. Crystallographic correlation between oxide particles and the matrix was investigated in a HIPped sample, and interactions between dislocations and oxide particles were observed in hot rolled or heat treated sample. Size distributions of oxide particles were measured by carbon replica samples and it was found that coarsening of oxide particles from 9 to 12 nm occurred during hot rolling process. Additional isothermal annealing at 1250 ˚C revealed that phase transformation of oxide particles from monoclinic YTaO4 to face centered cubic Y3TaO7 was observed.

When a drop is deposited on a superhydrophilic micropillar array, the upper part of the drop (referred to as the bulk) collapses while the bottom part penetrates into the gaps of the array, forming a fringe film. Here we quantify the early stage dynamics of this process using a combination of experiment and theory. We show that the circular front of the fringe film spreads like t1/2, t being time, when coupled to the bulk flow. However, the film is found to advance like t1/3 through faceted zippering in the absence of the bulk. We then show that the spreading of the bulk and the entire drop footprint follows a power law (t1/4) that is different from Washburn's law. This work can be a starting point to completely understand the spreading of liquids on superhydrophilic surfaces and opens questions specific to superwetting behaviour including the criteria to determine whether the fringe film will expand through lateral zipping or advance radially outwards.

High-resolution imaging and quantitative surface analysis of epicuticular waxes and epistomatal chambers of pine species were performed by field emission scanning electron microscopy and white light scanning interferometry. Both juvenile and adult needles were collected from the two-year-old seedlings of Pinus rigida and Pinus densiflora and subjected to surface observations. Epicuticular wax structures developed on the cuticle layer as well as in the epistomatal chambers and appeared to occlude the cavities in the two pine species. The stomata of P. densiflora were characterized by more distinctly raised rings around openings than P. rigida. The most common epicuticular wax structures of the two pine species included tubules with terminal openings and coiled rodlets. Wax platelets were deposited on epistomatal chambers. Either rodlets or tubules seemed to be longer and thicker in P. rigida than those in P. densiflora. White light scanning interferometry revealed quantitative surface profiles, demonstrating more ridged (ca. 4 μm high) stomatal apertures and nearly twofold deeper (ca. 20 μm deep) epistomatal chambers of P. densiflora than those of P. rigida. These results suggest that white light scanning interferometry can be applied to unravel the quantitative surface features of epicuticular sculptures on plant leaves.

A method allowing for the stable growth of carbon nanotubes (CNTs) on the surface of a fibrous metal mesh substrate (SUS304) was developed with the assistance of the microwave plasma-enhanced chemical vapor deposition process. The controlled addition of up to ∼13% of O2 to the CH4 plasma reacting gas flow was found to promote the growth of the CNTs by oxidizing the amorphous carbon and removing the active H2 radicals. However, excessive amounts of O2 (i.e., fraction of O2 > ∼13%) and H2 were found to play a negative role in the growth of the CNTs. The control of the density and length of the CNTs was also achieved by varying the H2 plasma reduction time and CH4 plasma reacting time, respectively. Longer H2 reduction pretreatment of the catalytic metal islands resulted in the formation of a less dense CNT forest with craters. When the growth time of the CNTs was increased to ∼20 min, their length was increased to ∼10 μm. However, when the growth time of the CNTs exceeded 20 min, their length was significantly decreased, indicating that the continuous presence of O2 in the CH4 plasma destroys the preformed CNTs due to the oxidation reaction.

We developed a new Cu–Zn wetting layer for Pb-free solders. By adding Zn to the Cu wetting layer, intermetallic growth in the Sn–Ag–Cu (SAC) solder interfaces was delayed. Cu3Sn intermetallic compounds and microvoids were not observed in the SAC/Cu–Zn interfaces after aging. The drop reliability of the SAC solder/Cu–Zn joints was excellent.

Vertically-aligned Mn (10%)-doped Fe3O4 (Fe2.7Mn0.3O4) nanowire arrays were produced by the reduction/substitution of pre-grown Fe2O3 nanowires. These nanowires were ferromagnetic with a Verwey temperature of 129 K. X-ray magnetic circular dichroism measurements revealed that the Mn2+ ions preferentially occupy the tetrahedral sites, substituting for the Fe3+ ions. We observed that the Mn substitution decreases the magnetization, but increases the electrical conductivity. We developed highly sensitive gas sensors using these nanowire arrays, operating at room temperature, whose sensitivity showed a correlation with their bond strength of diatomic/triatomic molecules. Based on the fact that the sensitivity was highest toward water vapor, an excellent-performance humidity sensor was fabricated.

Quality Si thin films were grown by the metal-induced growth (MIG) method. Metal (Co, Ni, or mixing of Co and Ni) was thermally evaporated on a 200 nm-SiO2 coated Si wafer. Si sputtering was performed at 600 – 620 °C in a dc magnetron system. The reaction of Si and metal first formed a silicide (CoSi2 or NiSi2) layer and further Si sputtering grew a Si film above it. The grown Si films were practically fabricated for Schottky photodiodes and electrically measured under one sun scan illumination (100 mW/cm2).

Silicon carbide (SiC) microtubes were synthesized and characterized via a vapor–solid (VS) reaction of carbon fiber (Csolid) and SiO(gas). The synthesis mechanisms were investigated. The precursor led complete conversion of [SiO(gas) + C(solid)] into [SiC(solid) + CO(gas)] through overall reaction under inert gas flow at and above 1350 °C. Carbon fibers with small surface area (0.7–2.0 m2 g−1) were gradually converted to SiC microtubes with large specific surface area (45–63 m2 g−1). Inner surface of SiC microtubes indicated a villus-like morphology, which consisted of submicron-sized SiC villi. The outer surface of the SiC microtubes was smooth. Inner surface morphology of SiC microtubes was dependent upon synthesizing temperature. Thickness of villus-like layer in SiC microtubes increased with increasing synthesizing temperature, showing 0.25 and 0.5 at 1350 and 1400 °C, respectively. Both VS and gas–liquid–solid (VLS) growth mechanisms were investigated in synthesis of SiC fiber as a reaction byproduct, and the reaction was governed by both growth mechanisms.

The structural properties of GaN epitaxial layers grown on patterned sapphire substrates by MOCVD have been investigated using HRXRD(high-resolution X-ray diffraction), GIXRD(grazing incidence X-ray diffraction) and PL(photoluminescence). For X-ray characterizations rocking curves for GaN (10·5), (00·2), (11·4) and (11·0) reflections for which incidence angles of X-rays are 32.0°, 17.3°, 11.0° and 0.34°, respectively, were measured. For (10·5), (00·2) and (11·4) reflections FWHMs of the rocking curves for a patterned substrate were broader than those for a unpatterned substrate, for (11·0) reflection, however, FWHM for a patterned substrate was much narrower than that for a unpatterned substrate. The normalized FWHM for all reflections decreases as the incidence angle of X-ray decreases. The results indicate that the crystalline quality in the surface region of the epilayer on a patterned substrate was especially improved because the penetration depth of X-ray depends on the incidence angle. The intensity of PL peak of the epilayer for a patterned substrate increased compared to that for a unpatterned substrate, and the increase in PL intensity is attributed to the reduction in dislocation density at the surface region revealed the by X-ray results.