Structures and Magnetic Properties of Tm1-yYyMn1-xCoxO3

The structure and magnetic properties of Tm1−y Y y Mn1−x Co x O3 with 0 ≦ x ≦ 0.5 and 0 ≦ y ≦ 0.3 were investigated by X-ray diffraction, specific heat and magnetization measurements. Thulium manganite TmMnO3 prepared by solid-state synthesis at ambient pressure is hexagonal and antiferromagnetic with a Nèel temperature T N of 86 K. The substitution of Y for Tm in TmMnO3 does not greatly affect the fundamental hexagonal structure. The magnetization and specific heat measurement results for Tm1−y Y y MnO3 can be qualitatively explained in terms of the dilution effect of Tm by Y. On the other hand, the structure of TmMn1−x Co x O3 changes gradually from hexagonal to orthorhombic with the substitution of Co for Mn; hexagonal and orthorhombic phases coexist in samples for x ≦ 0.3 whereas TmMn0.6Co0.4O3 is almost a single orthorhombic phase. The magnetization of TmMn0.6Co0.4O3 in a field of 250 Oe increases rapidly at about 60K with decreasing temperature. The difference between zero-field-cooled (ZFC) and field-cooled (FC) magnetizations increases remarkably at about 60 K. Moreover, the temperature dependences of the ZFC and the FC magnetizations exhibit peaks at about 40 and 30K, respectively. Thus, TmMn1−x Co x O3 exhibits complex magnetic properties

Study on nutrient supply in relation to feeding system of buffalo in Chitwan, Nepal

Livestock farming in Nepal, especially buffalo farming alone contributes a major share in livelihoods of farmers. Stall feeding of buffalo is common in Chitwan with occasional grazing. This raises questions about status of nutrients supplied to maintain productivity as feed resources varied in forest and crop land according to the season. A study was carried out in Chitwan from April 2015 to March 2016 to find out the status of nutrient supply in relation to the feeding system of buffalo. Total fifteen farms were selected from three villages, the amount of feedstuff fed to the animals was measured every month and the nutrient contents of the feed were analyzed. The mean concentrations of DM, CP, TDN, Ca and P were 641g/kg, 75.0 g/kg, 462 g/kg, 4.9 g/kg and 4.2 g/kg. A significant difference of CP contents among the villages was observed (72.0 g/kg, 70.7 g/kg and 81.2 g/kg (P<0.01), and the highest content of CP, TDN, Ca and P were found in July (P<0.05)). The study showed variation in nutrient supplied, irrespective of the status and condition of buffalo in the farms which need to be considered to maintain productivity of the animals

Effect of Prelithiation Process for Hard Carbon Negative Electrode on the Rate and Cycling Behaviors of Lithium-Ion Batteries

Two prelithiation processes (shallow Li-ion insertion, and thrice-repeated deep Li-ion　insertion and extraction) were applied to the hard carbon (HC) negative electrode (NE) used in　lithium-ion batteries (LIBs). LIB full-cells were assembled using Li(Ni0.5Co0.2Mn0.3)O2 positive　electrodes (PEs) and the prelithiated HC NEs. The assembled full-cells were charged and discharged　under a low current density, increasing current densities in a stepwise manner, and then constant　under a high current density. The prelithiation process of shallow Li-ion insertion resulted in the　high Coulombic efficiency (CE) of the full-cell at the initial charge-discharge cycles as well as in a　superior rate capability. The prelithiation process of thrice-repeated Li-ion insertion and extraction　attained an even higher CE and a high charge-discharge specific capacity under a low current density.　However, both prelithiation processes decreased the capacity retention during charge-discharge　cycling under a high current density, ascertaining a trade-off relationship between the increased CE　and the cycling performance. Further elimination of the irreversible capacity of the HC NE was　responsible for the higher utilization of both the PE and NE, attaining higher initial performances,　but allowing the larger capacity to fade throughout charge-discharge cycling

Electrochemical Impedance Spectroscopy on the Performance Degradation of LiFePO4/Graphite Lithium-Ion Battery Due to Charge-Discharge Cycling under Different C-Rates

Lithium-ion batteries (LIBs) using a LiFePO4 cathode and graphite anode were assembled in　coin cell form and subjected to 1000 charge-discharge cycles at 1, 2, and 5 C at 25 C. The performance　degradation of the LIB cells under di erent C-rates was analyzed by electrochemical impedance　spectroscopy (EIS) and scanning electron microscopy. The most severe degradation occurred at 2 C　while degradation was mitigated at the highest C-rate of 5 C. EIS data of the equivalent circuit model　provided information on the changes in the internal resistance. The charge-transfer resistance within　all the cells increased after the cycle test, with the cell cycled at 2 C presenting the greatest increment　in the charge-transfer resistance. Agglomerates were observed on the graphite anodes of the cells　cycled at 2 and 5 C; these were more abundantly produced in the former cell. The lower degradation　of the cell cycled at 5 C was attributed to the lowered capacity utilization of the anode. The larger cell　voltage drop caused by the increased C-rate reduced the electrode potential variation allocated to the　net electrochemical reactions, contributing to the charge-discharge specific capacity of the cells

A Zebrafish Chemical Suppressor Screening Identifies Small Molecule Inhibitors of the Wnt/β-catenin Pathway

SummaryGenetic screening for suppressor mutants has been successfully used to identify important signaling regulators. Using an analogy to genetic suppressor screening, we developed a chemical suppressor screening method to identify inhibitors of the Wnt/β-catenin signaling pathway. We used zebrafish embryos in which chemically induced β-catenin accumulation led to an “eyeless” phenotype and conducted a pilot screening for compounds that restored eye development. This approach allowed us to identify geranylgeranyltransferase inhibitor 286 (GGTI-286), a geranylgeranyltransferase (GGTase) inhibitor. Our follow-up studies showed that GGTI-286 reduces nuclear localization of β-catenin and transcription dependent on β-catenin/T cell factor in mammalian cells. In addition to pharmacological inhibition, GGTase gene knockdown also attenuates the nuclear function of β-catenin. Overall, we validate our chemical suppressor screening as a method for identifying Wnt/β-catenin pathway inhibitors and implicate GGTase as a potential therapeutic target for Wnt-activated cancers

Suitable binder for Li‑ion battery anode produced from rice husk

Rice husk (RH) is a globally abundant and sustainable bioresource composed of lignocellulose and　inorganic components, the majority of which consist of silicon oxides (approximately 20% w/w in　dried RH). In this work, a RH-derived C/SiOx composite (RHC) was prepared by carbonization at　1000 °C for use in Li-ion battery anodes. To find a suitable binder for RHC, the RHC-based electrodes　were fabricated using two different contemporary aqueous binders: polyacrylic acid (PAA) and a　combination of carboxymethyl cellulose and styrene butadiene rubber (CMC/SBR). The rate and　cycling performances of the RHC electrodes with respect to the insertion/extraction of Li ions were　evaluated in a half-cell configuration. The cell was shorted for 24 h to completely lithiate the RHC.　Impedance analysis was conducted to identify the source of the increase in the resistance of the　RHC electrodes. The RHC electrode fabricated using PAA exhibited higher specific capacity for Li-ion　extraction during the cycling test. The PAA binder strengthened the electrode and alleviated the　increase in electrode resistance caused by the formation of the interphase film. The high affinity of　PAA for SiOx　in RHC was responsible for the stabilization of the anodic performance of Li-ion batteries

Role of SiOx in rice-husk-derived anodes for Li-ion batteries

The present study investigated the role of SiOx in a rice-husk-derived C/SiOx anode on the rate and cycling performance of a Li-ion battery. C/SiOx active materials with different SiOx contents (45, 24, and 5 mass%) were prepared from rice husk by heat treatment and immersion in NaOH solution. The C and SiOx specific capacities were 375 and 475 mAh g(-1), respectively. A stable anodic operation was achieved by pre-lithiating the C/SiOx anode. Full-cells consisting of this anode and a Li(Ni-0.5,Co-0.2,Mn-0.3) O-2 cathode displayed high initial Coulombic efficiency (similar to 85%) and high discharge specific capacity, indicating the maximum performance of the cathode (similar to 150 mAh g(-1)). At increased current density, the higher the SiOx content, the higher the specific capacity retention, suggesting that the time response of the reversible reaction of SiOx with Li ions is faster than that of the C component. The full-cell with the highest SiOx content exhibited the largest decrease in cell specific capacity during the cycle test. The structural decay caused by the volume expansion of SiOx during Li-ion uptake and release degraded the cycling performance. Based on its high production yield and electrochemical benefits, degree of cycling performance degradation, and disadvantages of its removal, SiOx is preferably retained for Li-ion battery anode applications

Effects of Excessive Prelithiation on Full-Cell Performance of Li-Ion Batteries with a Hard-Carbon/Nanosized-Si Composite Anode

The effects of excessive prelithiation on the full-cell performance of Li-ion batteries (LIBs) with a hard-carbon/nanosized-Si (HC/N-Si) composite anode were investigated; HC and N-Si simply mixed at mass ratios of 9:1 and 8:2 were analyzed. CR2032-type half- and full-cells were assembled to evaluate the electrochemical LIB anode behavior. The galvanostatic measurements of half-cell configurations revealed that the composite anode with an 8:2 HC/N-Si mass ratio exhibited a high capacity (531 mAh g(-1)) at 0.1 C and superior current-rate dependence (rate performance) at 0.1-10 C. To evaluate the practical LIB anode performance, the optimally performing composite anode was used in the full cell. Prior to full-cell assembly, the composite anodes were prelithiated via electrochemical Li doping at different cutoff anodic specific capacities (200-600 mAh g(-1)). The composite anode was paired with a LiNi0.5Co0.2Mn0.3O2 cathode to construct full-cells, the performance of which was evaluated by conducting sequential rate and cycling performance tests. Prelithiation affected only the cycling performance, without affecting the rate performance. Excellent capacity retention was observed in the full-cells with prelithiation conducted at cutoff anodic specific capacities greater than or equal to 500 mAh g(-1)