Miwako Ito

Grain-size dependent demagnetizing factors in permanent magnets

The coercive field of permanent magnets decreases with increasing grain size. The grain size dependence of coercivity is explained by a size dependent demagnetizing factor. In Dy free Nd2Fe14B magnets, the size dependent demagnetizing factor ranges from 0.2 for a grain size of 55 nm to 1.22 for a grain size of 8300 nm. The comparison of experimental data with micromagnetic simulations suggests that the grain size dependence of the coercive field in hard magnets is due to the non-uniform magnetostatic field in polyhedral grains.

Influence of Amylose Content on Cookie and Sponge Cake Quality and Solvent Retention Capacities in Wheat Flour

ABSTRACT Reduced amylose wheat (Triticum aestivum L.) produces better quality noodles and bread less prone to going stale, while little is known about the relationships between amylose content and the quality of soft wheat baking products such as sugar snap cookies (SSC) and Japanese sponge cakes (JSC). Near-isogenic lines developed from wheat cultivar Norin 61, differing in their level of granule-bound starch synthase (Wx protein) activity, were used to produce wheat grains and ultimately flours of different amylose contents. These were tested with regard to their effect on soft wheat baking quality and solvent retention capacities (SRC). Amylose content was strongly correlated to cookie diameter (r = 0.969, P < 0.001) and cake volume (r = 0.976, P < 0.001), indicating that the soft wheat baking quality associated with SSC diameter and JSC volume were improved by an incremental increases in amylose content. Among the four kinds of SRC tests (water, sodium carbonate, sucrose and lactic acid), the water SRC...

Deoxynivalenol Distribution in Flour and Bran of Spring Wheat Lines with Different Levels of Fusarium Head Blight Resistance

The level of the fungal toxin deoxynivalenol (DON) in milled flour and its partitioning between flour and bran of 15 spring wheat (Triticum aestivum) lines with different levels of Fusarium head blight (FHB; mainly caused by Fusarium graminearum) resistance was investigated in Hokkaido, Japan between 2004 and 2007. The DON levels in flour (DONf) and bran (DONb) showed positive linear relationships with DON levels in whole kernels (DONk) (R2 = 0.94, n = 60, P ≤ 0.01 and R2 = 0.93, n = 60, P ≤ 0.01, respectively). Results indicated that the DON partitioning ratio between flour and bran is primarily related to the level of DONk, and the DON level was approximately doubled in DONb and halved in DONf for any level of DONk. Only one pattern of DON partitioning supported the conventional strategy to select FHB-resistant lines.

Coercivity enhancement in Ce-Fe-B based magnets by core-shell grain structuring

Ce-based R2Fe14B (R= rare-earth) nano-structured permanent magnets consisting of (Ce,Nd)2Fe14B core-shell grains separated by a non-magnetic grain boundary phase, in which the relative amount of Nd to Ce is higher in the shell of the magnetic grain than in its core, were fabricated by Nd-Cu infiltration into (Ce,Nd)2Fe14B hot-deformed magnets. The coercivity values of infiltrated core-shell structured magnets are superior to those of as-hot-deformed magnets with the same overall Nd content. This is attributed to the higher value of magnetocrystalline anisotropy of the shell phase in the core-shell structured infiltrated magnets compared to the homogeneous R2Fe14B grains of the as-hot-deformed magnets, and to magnetic isolation of R2Fe14B grains by the infiltrated grain boundary phase. First order reversal curve (FORC) diagrams suggest that the higher anisotropy shell suppresses initial magnetization reversal at the edges and corners of the R2Fe14B grains.

Solid-solution stability and preferential site-occupancy in (R-R′)2Fe14B compounds

The rare-earth (R) uniaxial anisotropy of R2Fe14B compounds with magnetic R atoms (e.g., Nd or Pr) is at the origin of the exceptional hard magnetic properties achieved in magnets based on these compounds. The uniaxial anisotropy found in Ce2Fe14B is attributed mainly to the magnetism of Fe. Ce is the most abundant R element and there has been much recent effort to fabricate magnets in which Ce is partially substituted for Nd. In the present neutron study of (R1−xCex)2Fe14B (R = La or Nd), Ce is found to enter the R2Fe14B phase over the entire composition range. The crystallographic parameters decrease with increasing Ce content and the Ce atoms preferentially occupy the smaller 4f sites. It is concluded that Ce in these (RR′)2Fe14B compounds essentially maintains the intermediate valence character found in Ce2Fe14B. It is proposed that, in this intermediate valence state, Ce weakly contributes to uniaxial anisotropy, thus making a link with the fact that significant coercivity is preserved in Ce-substitu...

Dough properties and bread-making quality-related characteristics of Yumechikara near-isogenic wheat lines carrying different Glu-B3 alleles

We investigated the relationships of three allelic variations in Glu-B3 (ab, g, and h) with dough properties and bread-making quality-related characteristics using near-isogenic lines (NILs) of ‘Yumechikara’ that commonly carry Glu-A1a, Glu-B1b, Glu-D1d, Glu-A3f, Glu-B3ab and Glu-D3a. Measurement of peak time (PT) in a 2-g mixograph indicated that Glu-B3g was the most effective for a strong dough property, followed by Glu-B3ab, with Glu-B3h being the least effective. The results of measurement of mixing time during bread-making were similar to those for PTs, i.e., the lines carrying Glu-B3g showed the longest mixing time, followed by those of Glu-B3ab, and those of Glu-B3h showed the shortest mixing time. Since two parameters of bread-making quality, loaf volume (LV) and specific loaf volume (SLV), were affected by flour protein contents in all groups of the Glu-B3 genotype, we compared the effects of the three Glu-B3 alleles on those parameters using analysis of covariance (ANCOVA) to remove the effect of protein content. The results indicated that the Glu-B3h group showed the largest SLV, followed by the Glu-B3ab group, and the Glu-B3g group showed the smallest SLV. These results suggest that the introduction of Glu-B3h into ‘Yumechikara’ makes it possible to breed varieties with good bread-making quality-related characteristics.

Mapping of a major QTL associated with protein content on chromosome 2B in hard red winter wheat (Triticum aestivum L.)

A quantitative trait locus (QTL) controlling wheat grain protein content (GPC) and flour protein content (FPC) was identified using doubled haploid (DH) lines developed from a cross between the hard red winter wheat variety ‘Yumechikara’ with a high protein content used for bread making, and the soft red winter wheat ‘Kitahonami’ with a low protein content used for Japanese white salted noodles. A single major QTL, QGpc.2B-yume, was identified on the short arm of wheat chromosome 2B for both the GPC and FPC over 3 years of testing. QGpc.2B-yume was mapped on the flanking region of microsatellite marker Xgpw4382. The DH lines grouped by the haplotype of the closest flanking microsatellite marker Xgpw4382 showed differences of 1.0% and 1.1% in mean GPC and FPC, respectively. Yield-component-related traits were not affected by the haplotype of QGpc.2B-yume, and major North American hard red winter wheat varieties showed the high-protein haplotype. Unlike Gpc-B1 derived from tetraploid wheat, QGpc.2B-yume has no negative effects on yield-component-related traits and should be useful for wheat breeding to increase GPC and FPC.

Evaluation of fresh pasta-making properties of extra-strong common wheat (Triticum aestivum L.)

The relationship between characterictics of flour of common wheat varieties and fresh pasta-making qualitites was examined, and the fresh pasta-making properties of extra-strong varieties that have extra-strong dough were evaluated. There was a positive correlation between mixing time (PT) and hardness of boiled pasta, indicating that the hardness of boiled pasta was affected by dough properties. Boiled pasta made from extra-strong varieties, Yumechikara, Hokkai 262 and Hokkai 259, was harder than that from other varieties and commercial flour. There was a negative correlation between flour protein content and brightness of boiled pasta. The colors of boiled pasta made from Yumechikara and Hokkai 262 grown under the condition of standard manuring culture were superior to those of boiled pasta made from other varieties. Discoloration of boiled pasta made from Yumechikara grown under the condition of heavy manuring culture was caused by increase of flour protein content. On the other hand, discoloration of boiled pasta made from Hokkai 262 grown under the condition of heavy manuring culture was less than that of boiled pasta made from Yumechikara. These results indicate that pasta made from extra-strong wheat varieties has good hardness and that Hokkai 262 has extraordinary fresh pasta-making properties.

Effect of Growing Environment of Soft Wheats on Amylose Content and Its Relationship with Cookie and Sponge Cake Quality and Solvent Retention Capacity

ABSTRACT The effect of growing environments of soft wheat on amylose content and its relationship with baking quality and solvent retention capacities (SRC) was investigated. Near-isogenic soft wheat lines of Norin 61 differing in granule-bound starch synthase (Wx protein) activity and grown in three different regions of Japan: Hokkaido (spring-sown) for 2006 and 2007, Kanto (autumn-sown), and Kyushu (autumn-sown) for 2007 were evaluated. Spring-sown samples produced grains of greater protein content (10.9–12.4%) than autumn-sown samples (7.3–9.1%). In contrast, spring-sown samples of 2007 with higher maturing temperature had lower amylose content (25.5% for Norin 61) compare to the autumn-sown and spring-sown samples of 2006 (27.6–28.4% for Norin 61). Amylose content was strongly correlated to sugar snap cookie (SSCD) diameter (r = 0.957–0.961; n = 10, all samples; P ≤ 0.001, r = 0.701–0.976; n = 7 partial waxy and nonwaxy samples; and Japanese sponge cake (JSCV) volume r = 0.971–0.993; n = 10; P≤ 0.001,...

Mapping a QTL conferring resistance to Fusarium head blight on chromosome 1B in winter wheat (Triticum aestivum L.)

Fusarium head blight (FHB) is one of the most devastating diseases of wheat (Triticum aestivum L.), and the development of cultivars with FHB resistance is the most effective way to control the disease. Yumechikara is a Japanese hard red winter wheat cultivar that shows moderate resistance to FHB with superior bread-making quality. To identify quantitative trait loci (QTLs) for FHB resistance in Yumechikara, we evaluated doubled haploid lines derived from a cross between Yumechikara and a moderate susceptible cultivar, Kitahonami, for FHB resistance in a 5-year field trial, and we analyzed polymorphic molecular markers between the parents. Our analysis of these markers identified two FHB-resistance QTLs, one from Yumechikara and one from Kitahonami. The QTL from Yumechikara, which explained 36.4% of the phenotypic variation, was mapped on the distal region of chromosome 1BS, which is closely linked to the low-molecular-weight glutenin subunit gene Glu-B3 and the glume color gene Rg-B1. The other QTL (from Kitahonami) was mapped on chromosome 3BS, which explained 11.2% of the phenotypic variation. The close linkage between the FHB-resistance QTL on 1BS, Glu-B3 and Rg-B1 brings an additional value of simultaneous screening for both quality and FHB resistance using the glume color.