87 research outputs found

    Quality Changes and Freezing Time Prediction During Freezing and Thawing of Ginger

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    Effects of different freezing rates and four different thawing methods on chemical composition, microstructure, and color of ginger were investigated. Computer simulation for predicting the freezing time of cylindrical ginger for two different freezing methods (slow and fast) was done using ANSYS¼ Multiphysics. Different freezing rates (slow and fast) and thawing methods significantly (P \u3c 0.05) affected the color and composition of essential oil in ginger. Fresh ginger was found to contain 3.60% gingerol and 18.30% zingerone. A maximum yield of 7.43% gingerol was obtained when slow frozen gingers when thawed by infrared method. Maximum zingerone content of 38.30% was achieved by thawing slow frozen gingers using infrared-microwave method. Microscopic examination revealed that structural damage was more pronounced in slow frozen gingers than fast frozen gingers. Simulated freezing curves were in good agreement with experimental measurements (r = 0.97 for slow freezing and r = 0.92 for fast freezing). Slow freezing damaged ginger’s cellular structure. Data obtained will be helpful in selecting appropriate thawing method to increase desirable essential oil components in ginger. Computer simulation for predicting freezing time may help in developing proper storage system of ginger

    Structure, spin correlations and magnetism of the S=1/2S = 1/2 square-lattice antiferromagnet Sr2_2CuTe1−x_{1-x}Wx_xO6_6 (0≀x≀10 \leq x \leq 1)

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    Quantum spin liquids are highly entangled magnetic states with exotic properties. The S=1/2S = 1/2 square-lattice Heisenberg model is one of the foundational models in frustrated magnetism with a predicted, but never observed, quantum spin liquid state. Isostructural double perovskites Sr2_2CuTeO6_6 and Sr2_2CuWO6_6 are physical realizations of this model, but have distinctly different types magnetic order and interactions due to a d10/d0d^{10}/d^0 effect. Long-range magnetic order is suppressed in the solid solution Sr2_2CuTe1−x_{1-x}Wx_xO6_6 in a wide region of x=0.05−0.6x = 0.05-0.6, where the ground state has been proposed to be a disorder-induced spin liquid. Here we show that the spin-liquid-like x=0.2x = 0.2 and x=0.5x = 0.5 samples have distinctly different local spin correlations, which suggests they have different ground states. Furthermore, the previously ignored interlayer coupling between the square-planes is likely to play a role in the suppression of magnetic order on the W-rich side at x≈0.6x \approx 0.6. These results highlight the complex magnetism of Sr2_2CuTe1−x_{1-x}Wx_xO6_6 and hint at a new quantum critical point at x≈0.3x \approx 0.3.Comment: 19+8 pages, 6+8 figure

    Structure, Spin Correlations, and Magnetism of the S = 1/2 Square-Lattice Antiferromagnet Sr2CuTe1-xWxO6 (0 ≀ x ≀ 1)

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    Quantum spin liquids are highly entangled magnetic states with exotic properties. The S = 1/2 square-lattice Heisenberg model is one of the foundational models in frustrated magnetism with a predicted, but never observed, quantum spin liquid state. Isostructural double perovskites Sr2CuTeO6 and Sr2CuWO6 are physical realizations of this model but have distinctly different types of magnetic order and interactions due to a d10/d0 effect. Long-range magnetic order is suppressed in the solid solution Sr2CuTe1-xWxO6 in a wide region of x = 0.05-0.6, where the ground state has been proposed to be a disorder-induced spin liquid. Here, we present a comprehensive neutron scattering study of this system. We show using polarized neutron scattering that the spin liquid-like x = 0.2 and x = 0.5 samples have distinctly different local spin correlations, which suggests that they have different ground states. Low-temperature neutron diffraction measurements of the magnetically ordered W-rich samples reveal magnetic phase separation, which suggests that the previously ignored interlayer coupling between the square planes plays a role in the suppression of magnetic order at x ≈ 0.6. These results highlight the complex magnetism of Sr2CuTe1-xWxO6 and hint at a new quantum critical point between 0.2 &lt; x &lt; 0.4.</p

    Structure and Magnetism of the Rh4+-containing perovskite oxides La0.5Sr0.5Mn0.5Rh0.5O3 and La0.5Sr0.5Fe0.5Rh0.5O3

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    Synchrotron X-ray powder diffraction data indicate that La0.5Sr0.5Mn0.5Rh0.5O3 and La0.5Sr0.5Fe0.5Rh0.5O3 adopt distorted perovskite structures (space group Pnma) with A-site and B-site cation disorder. A combination of XPS and 57Fe Mössbauer data indicate the transition metal cations in the two phases adopt Mn3+/Rh4+ and Fe3+/Rh4+ oxidation state combinations respectively. Transport data indicate both phases are insulating, with ρ vs. T dependences consistent with 3D variable-range hopping. Magnetisation data reveal that La0.5Sr0.5Mn0.5Rh0.5O3 adopts a ferromagnetic state below Tc ∌ 60 K, which is rationalized on the basis of coupling via a dynamic Jahn–Teller distortion mechanism. In contrast, magnetic data reveal La0.5Sr0.5Fe0.5Rh0.5O3 undergoes a transition to a spin-glass state at T ∌ 45 K, attributed to frustration between nearest-neighbour Fe–Rh and next-nearest-neighbour Fe–Fe couplings

    Conductivity and redox stability of new double perovskite oxide Sr 1.6 K 0.4 Fe 1+ x Mo 1− x O 6− ή (x= 0.2, 0.4, 0.6)

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    A series of new perovskite oxides Sr1.6K0.4Fe1+xMo1−xO6−ή (x = 0.2, 0.4, 0.6) were synthesised by solid state reaction method. Synthesis of Sr1.6K0.4Fe1+xMo1−xO6−ή (x = 0.2, 0.4, 0.6) was achieved above 700 °C in 5 % H2/Ar, albeit with the formation of impurity phases. Phase stability upon redox cycling was only observed for sample Sr1.6K0.4Fe1.4Mo0.6O6−ή. Redox cycling of Sr1.6K0.4Fe1+xMo1−xO6−ή (x = 0.2, 0.4, 0.6) demonstrates a strong dependence on high temperature reduction to achieve high conductivities. After the initial reduction at 1200 °C in 5 %H2/Ar, then re-oxidation in air at 700 °C and further reduction at 700 °C in 5 %H2/Ar, the attained conductivities were between 0.1 and 58.4 % of the initial conductivity after reduction 1200 °C in 5 %H2/Ar depending on the composition. In the investigated new oxides, sample Sr1.6K0.4Fe1.4Mo0.6O6−ή is most redox stable also retains reasonably high electrical conductivity, ~70 S/cm after reduction at 1200 °C and 2–3 S/cm after redox cycling at 700 °C, indicating it is a potential anode for SOFCs

    CD34+ cell mobilization, blood graft composition, and posttransplant recovery in myeloma patients compared to non‐HodgkinÊŒs lymphoma patients: results of the prospective multicenter GOA study

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    BACKGROUNDAutologous stem cell transplantation is an established treatment option for patients with multiple myeloma (MM) or non‐HodgkinÊŒs lymphoma (NHL).STUDY DESIGN AND METHODSIn this prospective multicenter study, 147 patients with MM were compared with 136 patients with NHL regarding the mobilization and apheresis of blood CD34+ cells, cellular composition of infused blood grafts, posttransplant recovery, and outcome.RESULTSMultiple myeloma patients mobilized CD34+ cells more effectively (6.3 × 106/kg vs. 3.9 × 106/kg, p = 0.001). The proportion of poor mobilizers (peak blood CD34+ cell count 100 days) nonrelapse mortality (NRM; 6% vs. 0%, p = 0.003).CONCLUSIONSNon‐HodgkinÊŒs lymphoma and MM patients differ in terms of mobilization of CD34+ cells, graft cellular composition, and posttransplant recovery. Thus, the optimal graft characteristics may also be different.</p
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