Search

The elevated temperature strength of multicomponent Al-Si alloys is greatly affected by the volume fraction and the interconnectivity of hard phases formed upon solidification. In the present investigation, such influences were examined for two Al-Si-Cu-Ni alloys with different total volume fractions of hard phases. To control the microstructural features related to the size of the phase, the specimens were prepared with and without ultrasonic melt treatment (UST) at different cooling rates. The microstructures of the alloys were composed of primary Si, eutectic Si, (Al,Si)3(Zr,Ni,Fe), Al9FeNi and Al3(Cu,Ni)2 phases. The microstructural features, such as the size and aspect ratio of each phase, changed with UST and cooling rate, and accordingly, the elevated temperature strength at 350 oC was changed. The alloy with a high volume fraction of about 30 vol.% exhibited increased elevated temperature strength at 350 oC when ultrasonic melt treated, and the alloy having a volume fraction as low as about 18 vol.% exhibited the opposite results. Considering the microstructural features of the multi-component Al-Si alloy, a hexagonal shear-lag model was suggested, based on the well-known shearlag model proposed by Nardone and Prewo (Scr. Metall. 20;1986:43-48). Using the 2-D microstructural factors such as the size, aspect ratio of the phase and secondary dendrite arm spacing, the elevated temperature strength was calculated and compared with the measured value. Based on the hexagonal shear-lag model, the influence of microstructural factors on the elevated temperature strength was discussed for multi-component Al-Si-Cu-Ni alloys.

The effect of ultrasonic melt treatment (UST) on the solidification microstructure of an Al–5Ti–1B alloy containing high-volume fractions of Al3Ti and TiB2 particles is investigated for various UST times with different melt holding times. The as-cast Al–5Ti–1B alloy is composed of TiB2 and polygonal Al3Ti particles (present prior to UST), plate-like Al3Ti particles, and Al grains (formed during UST and/or solidification). The UST causes a size reduction and homogeneous distribution of the TiB2-agglomerated region containing many submicron-sized TiB2 particles pushed to the grain boundaries. The UST slightly decreases the size and improves the distribution of polygonal Al3Ti particles enriched in the TiB2-agglomerated region. Unlike the TiB2 and polygonal Al3Ti particles, which exhibit a minor refining effect, the plate-like Al3Ti particles show a significant refinement with UST application. The UST has a significant effect on the size distribution of Al grains by inducing the formation of medium-sized grains at the expense of small and large grains; however, it only has a slight effect on grain refinement. The degree of microstructure modification increases with increasing UST time but decreases with melt holding time after UST. The mechanisms for the refinement and dispersion of the TiB2 and Al3Ti particles and Al grains are discussed considering fragmentation, nucleation, and growth behaviors induced by the UST and subsequent solidification.

This work probes the effect of ultrasonic melt treatment (UST) on primary intermetallic particles and α-Al using pure Al and Al–Zr alloys (Al–0.3Zr–0.1Ti, Al–0.5Zr, Al–0.5Zr–0.5Mg–0.9Si) solidified at various cooling rates of 0.2–70 K s−1. The application of UST is shown to decrease the size and increase the number density and volume fraction of D023-structured primary Al3Zr and Al3(Zr,Ti) particles with a high nucleation potency for α-Al formation. High-resolution transmission electron microscopy analysis reveals that the cavitation-induced wetting and dispersion of γ-Al2O3 inoculant particles contribute to the refinement of primary intermetallic particles. The grain size of Al–Zr alloys increases with increasing cooling rate because of the concomitantly reduced formation of primary intermetallic inoculant particles. The UST-induced refinement of primary Al3Zr particles and the increased number density lead to grain refinement in Ti-free Al–Zr alloys. For the Ti-containing Al–Zr alloy, UST-induced grain refinement is achieved only at a very low cooling rate of 0.2 K s−1, possibly because of the side effects of UST on the growth-restricting influence of Ti. The fast cooling–induced solidification enables significant age-hardening by L12-Al3Zr nanoprecipitation (~5 nm) and is not affected by UST. Thus, this study shows that UST can be used to reduce the degree of grain coarsening of age-hardenable Al–Zr alloys at high cooling rates.

Purpose: This study aimed to explore the knowledge of and attitude toward breastfeeding among medical staff working in the neonatal intensive care unit and obstetric unit.Methods: A cross-sectional survey design was used. The questionnaire focused on participants’ knowledge of and attitude toward breastfeeding and their characteristics. A total of 123 participants, including nurses and physicians working in the neonatal intensive care unit and obstetric unit, completed the questionnaire. Data were analyzed using descriptive statistics, chi-square test, Fisher exact test, and Spearman correlation coefficient.Results: One-third the of participants reported that they had obtained formal education related to breastfeeding within the last year, 44% of participants obtained information related to breastfeeding from books, while 30.9% of participants learned from coworkers. Over 93% of the participants reported a need for formal breastfeeding education. The rate of correct answers for breastfeeding knowledge was 59.2%, and there were no significant differences between the nurse and physician groups. Breastfeeding attitude was positive with a score of 60.0, and nurses working in the obstetric unit scored higher than other nurse or physician groups (p=0.014). A significant correlation between knowledge of and attitude toward breastfeeding was found in medical staff attending to preterm infant mothers (p

Ultrasonic melt treatment (UST) is known for refining microstructures including intermetallic compound (IMC)s, and it is expected that the microstructural benefits induced by UST may reduce the tim...

The number of English Language Learners (ELLs) has been growing worldwide. ELLs are at risk for reading disabilities due to dual difficulties with linguistic and cultural factors. This raises the need for finding practical and efficient reading interventions for ELLs to improve their literacy development and English reading skills. The purpose of this study is to examine the evidence-based reading interventions for English Language Learners to identify the components that create the most effective and efficient interventions. This article reviewed literature published between January 2008 and March 2018 that examined the effectiveness of reading interventions for ELLs. We analyzed the effect sizes of reading intervention programs for ELLs and explored the variables that affect reading interventions using a multilevel meta-analysis. We examined moderator variables such as student-related variables (grades, exceptionality, SES), measurement-related variables (standardization, reliability), intervention-related variables (contents of interventions, intervention types), and implementation-related variables (instructor, group size). The results showed medium effect sizes for interventions targeting basic reading skills for ELLs. Medium-size group interventions and strategy-embedded interventions were more important for ELLs who were at risk for reading disabilities. These findings suggested that we should consider the reading problems of ELLs and apply the Tier 2 approach for ELLs with reading problems., English language learners, Evidenced-based intervention, Meta-analysis, Reading.

Ultrasonic melt treatment (UST) was applied to Al-7Si-2Cu-1Mg melt at various temperatures of 620, 650, 700 and 785 °C. MgAl2O4 particles which were often found to be densely populated along oxide films, became effectively dispersed and well-wetted by UST. Transmission electron microscopy work combined with crystallography analysis clearly indicates that MgAl2O4 particles can act as α-Al nucleation site with the aid of UST. However, with UST, grain refinement occurred only at temperature of 620 °C and the grain size increased from 97 to 351 μm with increase of melt temperature to 785 °C for UST. In quantitative analysis of grain size and MgAl2O4 particle diameter, it was found that ultrasonic de-agglomeration decreased mean particle size of the MgAl2O4 particles, significantly reducing size from 1.2 to 0.4 μm when temperature increased from 620 to 785 °C. Such a size reduction with increased number of MgAl2O4 particles does not always guarantee grain refinement. Thus, in this work, detailed condition for achieving grain refinement by UST is discussed based on quantitative measurement. Furthermore, we tried to suggest the most valid grain refinement mechanism among the known mechanisms by investigation of the relationship between grain size and particle size with variation of melt temperature.

Interfacial and emulsifying properties of fractionated cricket powder were assessed to identify whether emulsification properties originate from protein or chitin particles. Fractions extracted in alkaline water, containing high protein and mineral contents, increased the surface pressure of heptane-water interfaces with near-saturation equilibrium surface pressure of 31 mN/m. Dynamic surface pressure profiles indicated adsorption of protein clusters to the interface. Emulsification capacity of protein fraction was 50% greater than that of the source cricket flour, although oil-in-water emulsions prepared with 1–2% (w/w) protein fraction formed a cream layer within one day of storage. Emulsified layers persisted for up to 20 days, and light scattering measurements described a stable population with surface-volume-mean diameter of approximately 3 μm. Chitin-rich fractions milled to a particle size of 0.5–200 μm contributed negligible surface pressure, and its emulsification capacity was 5% of the value for the source cricket flour. Emulsions prepared with chitin-rich fractions coexisted with an unstable precipitate layer comprising 60% of the added solid, which was attributed to larger particles with poor emulsifying capability. Stable chitin-stabilized emulsion phases were resistant to creaming, yet volume-mean droplet diameter surpassed 50 μm within 24 h of storage. Both protein and chitin fractions have emulsifying capabilities but would require further processing or secondary additives to achieve desirable storage stability., Graphical abstract Image 1, Highlights • Alkali-extracted proteins and chitin particles were obtained from ground cricket. • Protein fractions demonstrated strong surface activity. • Protein-stabilized emulsions creamed quickly but droplets grew slowly. • Only smallest of micrometer-scale chitin particles participated in emulsification. • Chitin-particle emulsions were prone to rapid droplet growth.

The purpose of study was to examine the physical self-conception and psychological well-being of elderly women participating in senior aerobics. The subjects of this study were 193 people in the elderly welfare center and seniors participating in senior aerobics in the northern part of Gyeongido (Uijeongbu, Yangju, Dongducheon, Pocheon). The survey tool used the physical self-concept scale developed by Kim Byung-Joon(2001) and the psychological well-being scale developed by Hwang Young-Joon(2009) as a questionnaire. The 5-point Likert scale was used. The collected data were analyzed by One-way ANOVA, correlation analysis, and multiple regression analysis. The results of this study were as follows ; First, there was no difference in age, physical self-concept and psychological well-being according to general characteristics(age, exercise duration, frequency, intensity). Second, the correlation between physical self-concept and psychological well-being was positively correlated. Third, physical self-concept is related to psychological well-being. Among the sub-factors of physical self-concept, appearance and overall physical factors influenced sub-factors of psychological well-being. The physical self-concept of elderly women who participated in senior aerobics partially affected psychological well-being.

The correlation between primary Si and silicide refinement induced by ultrasonic treatment (UST) of multicomponent Al–Si alloy containing Ti, Zr, V, and P was investigated. UST significantly refined the primary Si phase owing to cavitation-induced wetting and deagglomeration of MgAl2O4 particles. Lowering the UST finish temperature caused deterioration of the degree of primary Si refinement, instead leading to silicide refinement. Cavitation-induced silicide nucleation on wetted MgAl2O4 consumed the MgAl2O4 particles, particularly in the case of primary Si nucleation. Similarly, the formation of an AlP phase on the silicide phase reduced the nucleation efficiency of the AlP phase. Poisoning of the MgAl2O4 and AlP phases by the silicide phase was responsible for the deterioration in primary Si refinement. Room-temperature tensile strength and high-temperature elongation were increased by UST and were dependent on the size of primary Si.

Aluminum alloys have been widely used in various industries, and continuous improvement in the properties of these alloys is required to meet consumer demand for high-performance devices. This review introduces five recent case studies where the CALPHAD method was applied in the development of high-performance Al alloys. CALPHAD calculations can reasonably predict the solidification microstructure of the Al-7Si-2Cu-1Mg alloy and 4343/3527/4343 brazing sheets, although, some deviations are caused by solid-state diffusion occurring during the actual solidification process. CALPHAD is useful for predicting the complex solidification behavior of Al-(12-18)Si piston alloys and Al-6Mg-9Si-10Cu-10Zn-3Ni natural composites, and the precipitation behavior of the Al matrix. The application of CALPHAD can also provide valuable information on the properties of Al alloys, such as that on the erosion of brazing sheets, fluidity of alloy melts, and refinement of secondary phases by melt treatment.

Antireflection coatings (ARCs) on an optical substrate appear to be highly effective for reducing reflectance for optical and photovoltaic (PV) panel applications. In this perspective, we have prepared and investigated the performance of silica nanoparticles (SNPs) ARC through a sol–gel process for the PV module applications. The ∼160-nm-thick sol–gel prepared SNPs have been coated on a glass substrate using the spin coating technique. The further vapor-phase treatment of hexamethyldisilazane (HMDS) on silica-coated glass results in contamination-resistant due to the existence of trimethylsilyl groups. The resultant-coated glass exhibits improvement in transmission by ∼3 % while reducing the refractive index value up to 1.17. The solar cell tested undercoated glass notifies the increase in current density of 34.24 to 35.17 mA / cm2 and improves the overall efficiency up to 3.13% as compared to the untreated glass. The results obtained in our study suggest an important future direction for the use of HMDS-treated SNPs in an outdoor PV module and solar collector applications.

Background Electronic health record (EHR) systems often face user resistance in hospitals, which results in a failure to acquire their full benefits. To implement the EHR successfully, it is crucial to reduce nurses’ resistance to use the system. This study aimed to investigate the factors associated with nurses’ resistance to use the EHR system. Methods A descriptive correlational study was conducted with nurses working at four university hospitals in Korea using self-administered questionnaires to measure user resistance behavior, resistance to change, perceived usefulness, perceived ease of use, perceived value, colleagues’ opinions, self-efficacy for change, and organizational support for change. Path analysis was performed to examine direct and indirect association with user resistance behavior. Results A total of 223 nurses completed the questionnaires. All seven factors were found to be significantly associated with user resistance, either directly or indirectly. The total effect on user resistance behavior was highest in resistance to change (0.65), followed by perceived usefulness (− 0.33); both had direct but no indirect effects. Conversely, self-efficacy for change (− 0.25), perceived value (− 0.21), colleagues’ opinions (− 0.16), perceived ease of use (− 0.16), and organizational support for change (− 0.05) had indirect but no direct effects. Conclusions The study examined the factors associated with nurses’ user resistance behavior after the implementation of a new EHR system. These findings could help hospitals develop better EHR implementation strategies to reduce user resistance behavior among the nursing staff.

The effect of Cu/Mg solute combined with ultrasonic melt treatment (UST) on the microstructure and mechanical properties of a hypoeutectic Al-7Si alloy was investigated. Cu up to 4 wt pct and Mg to 1 wt pct were added to the alloy and UST was performed at about 100 °C above the liquidus temperature. UST at such a high temperature was ineffective in refining grain sizes but enhanced the microstructural homogeneity of the alloys with the refinement of α-Al secondary dendrite arm spacing (SDAS). It was found that both the grain size and the SDAS were solute sensitive: In the Al-7Si alloy with UST they insignificantly changed with Cu but decreased with an increase in Mg content. Along with the structural refinement, UST was likely to affect the solute redistribution and the subsequent formation of secondary phases (e.g., eutectic Si and Cu/Mg-rich intermetallic compounds (IMCs)). Quantitative analysis indicated that UST had significantly minimized microsegregation of Cu and Mg solutes, decreasing the amount of the IMCs finely and uniformly distributed. The underlying reason was attributed to the reduction in the size of the SDAS, which enabled the solid-state diffusion to occur more efficiently upon solidification. The most significant increase in the tensile properties was achieved for the Al-7Si-2Cu-1Mg alloy with UST where the SDAS was well refined and the grain size was the smallest among the alloys investigated. The important role of UST on the casting structure refinement and the solute distribution is discussed and the resulting mechanical properties are further explored.

Ultrasonic melt treatment (UST) was applied to an A390 hypereutectic Al–Si alloy in a temperature range of 750–800 °C and its influence on the solidification structure and the consequent increase in strength was investigated. UST at such a high temperature, which is about 100 °C above the liquidus temperature, had little effect on the grain refinement but enhanced the homogeneity of the microstructure with the uniform distribution of constituent phases (e.g. primary Si, α-Al and intermetallics) significantly refined. With the microstructural homogeneity, quantitative analysis confirmed that UST was found to suppress the formation of Cu-bearing phases, i.e., Q-Al5Cu2Mg8Si6, Al2Cu phases that form in the final stage of solidification while notably increasing the average Cu contents in the matrix from 1.29 to 2.06 wt%. A tensile test exhibits an increase in the yield strength of the as-cast alloy from 185 to 208 MPa, which is mainly associated with the solute increment within the matrix. The important role of UST in the microstructure evolution during solidification is discussed and the mechanism covering the microstructure-strengthening interrelationship of the ultrasonically treated A390 alloy is proposed.

A mechanism describing the synergistic effect of ultrasonic melt treatment (UST) and subsequent fast cooling on the refinement of primary Si particles in a hypereutectic Al−Si alloy was investigated by examining inoculant particles via high-resolution transmission electron microscopy, serial sectioning, and melt filtration. The application of UST activated non-wetting MgAl2O4 particles with diameters of ∼0.5 μm to nucleate the primary Si phase. The cavitation-enhanced wetting of MgAl2O4 particles caused the formation of the AlP phase at the MgAl2O4 interface, further improving the nucleation potential. The cavitation-enhanced wetting and dispersion of inclusions (such as MgAl2O4) also resulted in the refinement and de-agglomeration of AlP particles. The UST-induced changes to the inoculant particles ultimately increased their number density, and the observed effects became more pronounced after increasing the degree of undercooling up to 20 K, leading to enhanced refinement of primary Si particles at higher cooling rates (up to 102 K s−1).

Lactic acid bacteria (LAB) are the common probiotics. Here, we investigated the antiviral protective effects of heat-killed LAB strain Lactobacillus casei DK128 (DK128) on influenza viruses. Intranasal treatment of mice with DK128 conferred protection against different subtypes of influenza viruses by lessening weight loss and lowering viral loads. Protection via heat-killed DK128 was correlated with an increase in alveolar macrophage cells in the lungs and airways, early induction of virus specific antibodies, reduced levels of pro-inflammatory cytokines and innate immune cells. Importantly, the mice that were protected against primary viral infection as a result of heat-killed DK128 pretreatment developed subsequent heterosubtypic immunity against secondary virus infection. For protection against influenza virus via heat-killed DK128 pretreatment, B cells and partially CD4 T cells but not CD8 T cells were required as inferred from studies using knockout mouse models. Our study provides insight into how hosts can be equipped with innate and adaptive immunity via heat-killed DK128 treatment to protect against influenza virus, supporting that heat-killed LAB may be developed as anti-virus probiotics.

This paper shows that the addition of transition elements significantly influences the microstructure and tensile properties of Al–12Si alloy cast under ultrasonic melt treatment (UST). The alloys contained primary Si, eutectic Si and a variety of intermetallic compounds (IMCs); the addition of Mn and Ni changed the solidification sequence by forming primary α-Al15(Fe,Mn)4Si2 and e-Al3Ni prior to primary Si formation. The primary Si and primary IMCs competitively consumed the nucleation sites introduced by UST, thereby influencing their refining efficiencies; the efficiency of primary Si refinement by UST increased with increasing the fraction of primary Si formed prior to IMC formation, whereas it deteriorated with increasing primary IMC fraction. The refining efficiency of eutectic Si and eutectic IMCs was not affected by the type and fraction of the primary phase. Using a Ti sonotrode for UST caused Ti contamination, resulting in grain refinement by forming Ti(Al,Si)3 particles and increasing the amount of Ti solutes. Regardless of transition elements content, the application of UST improved the tensile strength at 25 °C and 350 °C. The refinement of IMCs caused by UST allowed the alloy to contain more IMCs without deterioration of room-temperature tensile strength. This enhanced the increment of high-temperature tensile strength by IMCs. Ductility of heavily alloyed systems was also improved by UST.

High-temperature stress often leads to differential RNA splicing, thus accumulating different types and/or amounts of mature mRNAs in eukaryotic cells. However, regulatory mechanisms underlying plant precursor mRNA (pre-mRNA) splicing in the environmental stress conditions remain elusive. Herein, we describe that a U5-snRNP-interacting protein homolog STABILIZED1 (STA1) has pre-mRNA splicing activity for heat-inducible transcripts including HEAT STRESS TRANSCRIPTION FACTORs and various HEAT SHOCK PROTEINs for the establishment of heat stress tolerance in Arabidopsis (Arabidopsis thaliana). Our cell-based splicing reporter assay demonstrated STA1 acts on pre-mRNA splicing for specific subsets of stress-related genes. Cellular reconstitution of heat-inducible transcription cascades supported the view that STA1-dependent pre-mRNA splicing plays a role in DREB2A-dependent HSFA3 expression for heat-responsive gene expression. Further genetic analysis with a loss-of-function mutant sta1-1, STA1-expressing transgenic plants in Col background, and STA1-expressing transgenic plants in the sta1-1 background verified that STA1 is essential in expression of necessary genes including HSFA3 for two-step heat stress tolerance in plants. However, constitutive overexpression of the cDNA version of HSFA3 in the sta1-1 background is unable to execute plant heat stress tolerance in sta1-1. Consistently our global target analysis of STA1 showed that its splicing activity modulates a rather broad range of gene expression in response to heat treatment. The findings of this study reveal that heat-inducible STA1 activity for pre-mRNA splicing serves as a molecular regulatory mechanism underlying the plant stress tolerance to high-temperature stress.

The effects of ultrasonic melt treatment (UST) on the microstructure and tensile properties of three multicomponent Al Si alloys with different Si contents (12, 15, and 18 wt%Si) and solution treatments were systematically investigated at room and elevated (350 °C) temperatures. The microstructures of these alloys consisted of primary Si, eutectic Si, Mg2Si, and various types of aluminides, but the average size and area fraction of the primary Si increased with Si content. The application of UST caused a transformation from dendritic to equiaxed cells and a reduction in grain size, with a significant reduction in the size of all secondary phases (i.e., Si, Mg2Si and aluminides). Both the strength and ductility at room and elevated temperatures were greatly improved by UST, mainly due to microstructure refinement. Improvements in the high-temperature tensile strength as a result of UST increased with increasing Si contents, due to the enhanced refinement of primary Si by UST with increasing Si contents. The spherodization of rigid phases induced by solution treatment can improve the strength and ductility at room temperature, but can also cause a loss of strength at elevated temperatures due to the relaxation of the interconnected network structure of rigid phases caused by their spherodization.

The purpose of this study was to present the current technology using the ubiquitous technology such as IoT and the elderly health exercise plan to make healthy ageing. IOT is applied in various fields and IOT needs to be applied in fitness field. In particular, in the current society where the elderly population is increasing, suggesting the exercise plan for the elderly health using ubiquitous technology can be “Healthy Ageing” by habitualizing exercise, maintaining and promoting exercise using the convenient and effective system of the ubiquitous era. First, the elderly exercise system plan of this study is to provide home sports care service by combining electronic devices and sports. Second is the training of trainers for home training. Third, we can provide connected fitness services such as the hospitals, nearby offline exercise service center using IoT. Forth, it is to connect fitness measure that the government provides by bus.

Proteins are one of the essential components of nutritional food materials and an excellent source for food-grade nanomaterials. This review focuses on select examples of nanoparticles assembled naturally, found in food-relevant materials, major approaches in assembling nanoscale structure from proteins, and general applications of protein nanoparticles in food or nutrition. Animal-sourced casein and non-animal grain storage proteins and legume storage proteins are discussed in terms of their structural assemblies. Protein solubility is a key factor in assembling protein nanoparticles with desired functional properties. Desolvation is the most common technique to prepare protein nanoparticles for insoluble proteins. Well-hydrated protein assemblies have been extensively studied through electrostatic complexes, assembled with fatty acid and starch, reassembled protein structure, and nanogels. These protein-based nanoparticles have been utilized for filler materials of films, encapsulation of bioactive molecules, and stabilization of emulsions. Most studies exploiting protein-based nanoparticles have focused on developing technologies in extraction of proteins from sources and assembly of nanoparticles in different environmental conditions.

Proteins are one of the essential components of nutritional food materials and an excellent source for food-grade nanomaterials. This review focuses on select examples of nanoparticles assembled naturally, found in food-relevant materials, major approaches in assembling nanoscale structure from proteins, and general applications of protein nanoparticles in food or nutrition. Animal-sourced casein and non-animal grain storage proteins and legume storage proteins are discussed in terms of their structural assemblies. Protein solubility is a key factor in assembling protein nanoparticles with desired functional properties. Desolvation is the most common technique to prepare protein nanoparticles for insoluble proteins. Well-hydrated protein assemblies have been extensively studied through electrostatic complexes, assembled with fatty acid and starch, reassembled protein structure, and nanogels. These protein-based nanoparticles have been utilized for filler materials of films, encapsulation of bioactive molecules, and stabilization of emulsions. Most studies exploiting protein-based nanoparticles have focused on developing technologies in extraction of proteins from sources and assembly of nanoparticles in different environmental conditions.

The combined effects of ultrasonic melt treatment (UST) with the cooling rate on the microstructural evolution in a multicomponent Al-14Si-CuNiMg casting alloy was investigated. UST was applied to a melt at 800°C, followed by casting into a steel step mold at cooling rates in the range of 4-32 K/s. UST in the fully liquid state significantly reduced the sizes of the primary phases (the phases formed before Al) crystallized in the initial stage of solidification, and the structural refinement by UST became more pronounced for a faster cooling. With trace additions of Ti, V and Zr, the primary phase is most likely (Al,Si)3(Zr,Ni,Fe), and primary Si and then Al3Ni are sequentially formed upon solidification. AlP particles, well-known nucleants for primary Si, were also found to exist inside the (Al,Si)3(Zr,Ni,Fe) and Al3Ni which exhibited a very low lattice misfit with AlP (~0.7 and 4.7%, respectively). This importantly suggests that AlP can nucleate all the primary phases while it has the highest efficiency of structural refinement by UST for (Al,Si)3(Zr,Ni,Fe) phase that first nucleated in the molten metal. The nucleation of the primary phases was quantified using an analytical model based on exponential statistics. The hierarchical refinement operated by UST is further discussed.

The effects of ultrasonic melt treatment (UST) on the microstructure and mechanical properties of Al-12.2Si-3.3Cu-2.4Ni-0.8Mg-0.1Fe (wt%) piston alloy were systematically investigated. Rigid colonies consisting of primary Si, eutectic Si, Mg 2 Si and various aluminides (e-Al 3 Ni, δ-Al 3 CuNi, π-Al 8 FeMg 3 Si 6 , γ-Al 7 Cu 4 Ni, Q-Al 5 Cu 2 Mg 8 Si 6 and θ-Al 2 Cu) were observed in the as-cast alloys. The sizes of the secondary phases, eutectic cell and grain were significantly decreased by UST because of the enhanced nucleation of each phase under ultrasonic irradiation. The yield strength, tensile strength and elongation at 25 °C were significantly improved by UST mainly because of the refinement of the microstructures. Both tensile strength and elongation at 350 °C were also improved by UST despite the unchanged yield strength.

Aluminum matrix composites with a high volume fraction of B4C and TiB2 were fabricated by a novel processing technique - a quick spontaneous infiltration process. The process combines a pressureless infiltration with the combustion reaction of Al-Ti-B4C-CuO in molten aluminum. The process is realized in a simple and economical way in which the whole process is performed in air in a few minutes. To verify the rapidity of the process, the infiltration kinetics was calculated based on the Washburn equation in which melt flows into a porous skeleton. However, there was a noticeable deviation from the calculated results with the experimental results. Considering the cross-sections of the samples at different processing times, a new infiltration model (two step infiltration) consisting of macro-infiltration and micro-infiltration is suggested. The calculated kinetics results in light of the proposed model agree well with the experimental results.

A trace addition of Zr to a multicomponent Al-14Si-3Cu-4.5Ni casting alloy has often been found to form a coarse plate-like Zr-rich intermetallic compound with a size of a few tens of μm at the beginning of solidification. Evaluation of the phase composition has confirmed that the Zr-rich intermetallic phase consists of multicomponent constituent elements, mainly Al, Si, Ni and Fe, and is present in a form of (Al,Si)3(Zr,Ni,Fe). The existence of such a complex (Al,Si)3(Zr,Ni,Fe) phase has not yet been predicted by phase equilibria calculation of the multicomponent Al-14Si-CuNiMg systems. In this paper, transmission electron microscopy studies combined with electron backscattered diffraction pattern analysis reveals the crystallography information of the (Al,Si)3(Zr,Ni,Fe) phase for the first time and identifies it as a modified Al3Zr-D023 crystal (tetragonal, I4/mmm(139)) with slightly changed lattice parameters of a = b = 3.275 A and c = 15.475 A. The primary (Al,Si)3(Zr,Ni,Fe) phase is found to nucleate directly onto AlP particles. The mechanical properties of the Zr-rich intermetallics were also investigated using nanoindentation at both room and elevated temperatures and were compared to those of the Si phase.

A melt-assisted solid flame synthesis approach was applied to synthesize boron nanoparticles in argon gas and air atmospheres. For this purpose, we investigated the characteristics of a thermally induced combustion wave in B 2 O 3 + α Mg mixtures ( α = 1.0–1.5 mol) in argon and air atmospheres. Utilizing stoichiometrically insufficient amounts of magnesium ensured that a large portion of molten B 2 O 3 remained in the sample, which reduced the combustion parameters and favored the formation of boron nanoparticles. Under these conditions the combustion temperature and burning velocity were controlled in the range of 1300–1580 °C and 0.065–0.18 cm/s, respectively, and boron nanoparticles in a ∼20–200 nm size range were obtained. The characteristics of boron nanoparticles (morphology, purity, specific surface area, oxidation activity, etc.) were analyzed and a reaction pathway leading to boron nanoparticles synthesis was proposed.

Arabidopsis BIK1 negatively regulates EIN3-depedent gene expression as an immediate cellular response. BIK1 localizes to the plasma membrane and its autophosphorylation and kinase activity involves in EIN3 repression. BOTRYTIS INDUCED KINASE1 (BIK1) is a multifunctional receptor-like kinase that involves in ethylene-mediated plant defense signaling. The loss of function BIK1 becomes insensitive to ethylene, but it still accumulates a higher level of ETHYLENE INSENSITIVE3 (EIN3) that serves as the key transcription activator in ethylene signaling. To unequivocally elucidate BIK1 function on EIN3 regulation in ethylene signaling, we took a combined approach of transient expression assay and stable expression analysis of BIK1. In our cell-based functional assay BIK1 destabilized EIN3 and down-regulated EIN3-dependent transcription. Membrane localization and autophosphorylation of BIK1 were required for full repression of EIN3 function, but its kinase activity potential compromised such regulatory action. Consistently, the analysis of transgenic plants verified BIK1 function on EIN3 repression. Our findings have clarified that autophosphorylated BIK1 in the plasma membrane negatively regulates EIN3-dependent gene expression. Thus, ethylene insensitivity in bik1 appears to be an indirect or a feedback long-term response.

The aim of this study was to manufacture functional high protein fermented beverage, using whey protein concentrate (WPC) and Lactobacillus plantarum DK211 isolated from kimchi, and to evaluate the physicochemical, functional, and sensory properties of the resulting product. The fermented whey beverage (FWB) was formulated with whey protein concentrate 80 (WPC 80), skim milk powder, and sucrose; and fermented with Lactobacillus plantarum DK211 as single, or mixed with Lactococcus lactis R704, a commercial starter culture. The pH, titratable acidity, and viable cell counts during fermentation and storage were evaluated. It was found that the mixed culture showed faster acid development than the single culture. The resulting FWB had high protein (9%) and low fat content (0.2%). Increased viscosity, and antioxidant and antimicrobial activity were observed after fermentation. A viable cell count of 10(9) CFU/mL in FWB was achieved within 10 h fermentation, and it remained throughout storage at 15℃ for 28 d. Sensory analysis was also conducted, and compared to that of a commercial protein drink. The sensory scores of FWB were similar to those of the commercial protein drink in most attributes, except sourness. The sourness was highly related with the high lactic acid content produced during fermentation. The results showed that WPC and vegetable origin lactic acid bacteria isolated from kimchi might be used for the development of a high protein fermented beverage, with improved functionality and organoleptic properties.

The number of Healthy Family Support Centers has dramatically increased and the services for healthy families such as family education, family counsel, family culture and family care have increased during the past ten years since the Framework Act on Healthy Families was enacted. This growth is largely credited to Healthy Family Specialists. At a time when the family policy delivery system is changing, it is most urgent to enhance the capability of Healthy Family Specialists. In this study, we aim to investigate the current capability of Healthy Family Specialists and suggest the education plan for their empowerment. We collected data from 151 Healthy Family Support Centers by mail and e-mail in June 2014. There were total of 1,001 subjects for analysis(781 by mail and 220 by e-mail). We analyzed the capabilities of Healthy Family Specialist by service areas according to work-related characteristics and possession of a license. Our findings revealed that the capabilities of Healthy Family Specialist varied depending on the service year and whether or not having a licence. These results suggest that the education program for empowerment will provide a differentiated content according to the service year and whether or not having a license. This study contributes to a better understanding of Healthy Family Specialists` current capability and provides insights on how to enhance their capability in order to change the family policy delivery system.