Fabrication of the High-Entropy Alloys and Recent Research Trends: A Review

High-entropy alloys (HEAs), which are defined as a single phase crystalline solid solution with the composition of each constituent element in the range of 5-35 at%, have been the subject of intensive study in the last decade. Most of the HEA research is focused on alloy design, microstructural characterization, and Mechanical testing, not manufacturing, processing, and industrialization, although the properties, microstructures, and performance are strongly dependent on processing. In this review article, we aim to describe the manufacturing processes applied to HEAs. The manufacturing process of HEAs can be classified into three main routes. First, liquid processing that includes arc melting, Bridgman solidification, atomization, and laser cladding is the most commonly used methods because the processing facilities are already widespread in many laboratory and the liquid processing can be easily scaled-up for commercialization. Second, mechanical alloying. i.e. powder metallurgy, is a process starting from a solid particle state and employing sintering procedures for bulk manufacturing. In particular, the mechanical alloying has been used for achieving super saturated solid solution which cannot be obtaiend using the conventional liquid prcesses. Third, the HEAs can be manufactured by mixing elements of the vapor state, which includes sputter deposition, atomic layer deposition, and vapor phase deposition. Explanation and comparison between various manufacturing methods of the HEAs are systematically described and demonstrated in this review.114Nsciescopuskc

Effect of ZnO/K2O ratio on the crystallization sequence and microstructure of lithium disilicate glass-ceramics

The effect of ZnO/K2O (Z/K) ratio on the crystallization sequence and microstructure of lithium disilicate (Li2Si2O5: LS2) glass-ceramics was carefully investigated for the SiO2-Li2O-K2O-ZnO-P2O5 system. The Z/K ratios of precursor glasses were varied from 0 to 3.5 while the nucleating agent of P2O5 and glass modifiers of ZnO plus K2O were fixed to have 1.5 and 4.5 mol% relative to LS2, respectively. For the samples prepared by two-stage heat treatments of 500 degrees C for 1 h and 800 degrees C for 2 h in air, the LS2 nucleation rate was increased with increasing the Z/K ratio due to the variation in crystallization sequence from type II (Li2SiO3: LS) to type I (LS + LS2) in addition to an amorphous phase separation in base glass. Consequently, with increasing the Z/K ratio, the LS2 crystalline phase within the glass matrix continuously changed from larger acicular ones to smaller equiaxed ones.N

The Rice Floral Repressor Early flowering1 Affects Spikelet Fertility By Modulating Gibberellin Signaling

al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.Background: Gibberellic acid (GA; or gibberellin) affects the development of floral organs, especially anthers and pollen, and perturbation of development of male floral organs can cause sterility. Many studies of GA signaling have concentrated on anther development, but the effect of GA on grain production remains to be examined. Results: Using a cross of Milyang23 (M23), which has a functional allele of Early flowering1 (EL1), and H143, which has a nonfunctional el1 allele, we generated heterogeneous inbred family-near isogenic lines (HNILs) that are homozygous for EL1 [HNIL(M23)] or el1 [HNIL(H143)]. Here, we found that HNIL(H143) exhibited anther deformities and low pollen viability. The expression of GAMYB, a major activator of GA signaling, and its downstream genes CYP703A3 and KAR, mainly involved in pollen formation, increased abnormally during spikelet development; this activation of GA signaling may cause the sterility. To confirm the negative effect of the el1 mutation on spikelet fertility, we examined a line carrying a T-DNA insertion el1 mutant [hereafter ZH11(el1)] and its parental cultivar Zhonghua11 (ZH11). ZH11(el1) showed nearly identical defects in anther development and pollen viability as HNIL(H143), leading to decreased seed setting rate. However, the elite japonica cultivar Koshihikari, which has a nonfunctional el1 allele for early flowering in long days, produces fertile spikelets and normal grain yields, like other elite japonica cultivars. This indicates that as-yet-unknown regulator(s) that can overcome the male sterile phenotype of the el1 mutation must have been introduced into Koshihikari. Conclusions: The el1 mutation contributes to early flowering in japonica rice under long days but fails to limit GA signaling, thus negatively affecting spikelet fertility, which results in a loss of grain yield. Thus, EL1 is essential for photoperiod sensitivity in flowering as well as spikelet fertility in grain production.OAIID:oai:osos.snu.ac.kr:snu2015-01/102/0000003606/9ADJUST_YN:YEMP_ID:A002118DEPT_CD:517CITE_RATE:3.919FILENAME:2015-8 el1-fertility (rice).pdfDEPT_NM:식물생산과학부SCOPUS_YN:YCONFIRM:

Two NADPH: Protochlorophyllide Oxidoreductase (POR) Isoforms Play Distinct Roles in Environmental Adaptation in Rice

Abstract Background NADPH: protochlorophyllide oxidoreductase (POR) is an essential enzyme that catalyzes the photoreduction of protochlorophyllide to chlorophyllide, which is ultimately converted to chlorophyll in developing leaves. Rice has two POR isoforms, OsPORA and OsPORB. OsPORA is expressed in the dark during early leaf development; OsPORB is expressed throughout leaf development regardless of light conditions. The faded green leaf ( fgl ) is a loss-of-function osporB mutant that displays necrotic lesions and variegation in the leaves due to destabilized grana thylakoids, and has increased numbers of plastoglobules in the chloroplasts. To investigate whether the function of OsPORA can complement that of OsPORB, we constitutively overexpressed OsPORA in fgl mutant. Results In the 35S:OsPORA/fgl (termed OPAO) transgenic plants, the necrotic lesions of the mutant disappeared and the levels of photosynthetic pigments and proteins, as well as plastid structure, were recovered in developing leaves under natural long days in the paddy field and under short days in an artificially controlled growth room. Under constant light conditions, however, total chlorophyll and carotenoid levels in the developing leaves of OPAO plants were lower than those of wild type. Moreover, the OPAO plants exhibited mild defects in mature leaves beginning at the early reproductive stage in the paddy field. Conclusions The physiological function of OsPORB in response to constant light or during reproductive growth cannot be completely replaced by constitutive activity of OsPORA, although the biochemical functions of OsPORA and OsPORB are redundant. Therefore, we suggest that the two OsPORs have differentiated over the course of evolution, playing distinct roles in the adaptation of rice to the environment