Effects of doping elements in ¢-FeSi2 prepared utilizing cast iron scrap chips

In this work, the thermoelectric properties of p- and n-type ¢-FeSi2, prepared utilizing cast iron scrap chips, have been characterized by measuring the Seebeck coefficient, electrical conductivity and thermal conductivity at temperatures ranging from room temperatures to 800°C. In a previous study, the upgrade recycling of cast iron scrap chips into ¢-FeSi2 thermoelectric materials was proposed as an eco-friendly and costeffective production process. By doping with different substitution concentrations of Co, Mn and Al, the conduction type and properties of ¢FeSi2 can be modified and improved using cast iron scrap chips as a starting material. The effects of the doping elements are discussed for preparing ¢-FeSi2 utilizing cast iron scrap chips. Cast iron scrap chips could be preferable as a starting material to replace pure Fe for n- and ptype ¢-FeSi2 thermoelectric materials. An optimum composition for n-type ¢-FeSi2 0.94C.I.-0.06Co-1.86Si shows that the largest ZT value of 0.22 occurs at 700°C, whereas for p-type ¢-FeSi2 0.92C.I.-0.08Mn-1.86Si, the largest ZT value of 0.17 occurs at 800°C

High-pressure and high-temperature synthesis of heavy lanthanide sesquisulfides Ln2S3 ( Ln=Yb and Lu)

Detailed pressure-temperature phase diagrams of heavy lanthanide sesquisulfides Ln2S3 (Ln = Yb and Lu) have been investigated by in-situ x-ray diffraction experiments under high pressure and high temperature using synchrotron radiation and multi-anvil press. Based on the results of the in-situ observation, the single γ-phase (Th3P4-type structure, I3d) samples of Ln2S3 (Ln = Yb and Lu) have been synthesized under high pressure. The physical properties of the compounds were studied by electrical resistivity, specific heat, and magnetic susceptibility measurements between 2 K and 300 K

Quantitative measurement of portal blood flow by magnetic resonance phase contrast: comparative study of flow phantom and Doppler ultrasound in vivo.

A non-invasive method for measuring portal blood flow by magnetic resonance (MR) phase contrast was evaluated in a flow phantom and 20 healthy volunteers. In a flow phantom study, the flow volumes and mean flow velocities measured by MR phase contrast showed close correlations with those measured by electromagnetic flowmetry. In 20 healthy volunteers, the cross-sectional areas, flow volumes and mean flow velocities measured by MR phase contrast correlated well with those measured by the Doppler ultrasound method. Portal blood flow averaged during the imaging time could be measured under natural breathing conditions by using a large number of acquisitions without the limitations imposed on the Doppler ultrasound method. MR phase contrast is considered to be useful for the non-invasive measurement of portal blood flow.</p

Effects of acute exercise on expressions of functional receptors on CD56dim and CD56bright natural killer cells

PURPOSE: Mobilization and cytotoxicity of natural killer (NK) cells are regulated by cell surface receptors such as adhesion molecules and activating/inhibitory receptors. In this study, we examined the effects of acute exercise on the expression of these cell surface molecules and receptors. METHODS: Six healthy male college students (22.8 ± 0.8 years olds) exercised on the cycle ergometer for 30 min at intensities corresponding to the individual onset of blood lactate accumulation level (70-85%VO2max). Venous blood samples were collected at rest (PRE); just before the end of exercise (END) and 30 (POST 30), 60 (POST 60), 120 (POST 120) and 180 (POST 180) min post exercise. The densities of cell surface molecules and receptors on CD56dim and CD56bright NK cells were determined by flow cytometry. One-way ANOVA and MANOVA were used for statistical analyses. RESULTS: At PRE, expressions of CD16, CD56, CD44, CD62L, CD314, CD335, CD159a and CX3CR1 differed between CD56dim and CD56bright NK cells. Expressions of adhesion molecules CD62L and CX3CR1 changed significantly in both subsets during and after exercise. The expressions of CD62L tended to decrease at END, and then they increased significantly at POST 30. These changes were mainly due to the proportional changes in CD62Lnegative cells. The opposite patterns of changes were seen in the expressions of CX3CR1. Additionally, the expressions of CX3CR1 decreased at POST 120 and 180 only in CD56dim NK cells. The changes in the expressions of CD44 were similar to those seen in the expressions of CD62L. Although changes in the expression of adhesion molecules were statistically significant, they were relatively unclear in histogram analyses. With regard to the expressions of NK cell activating/inhibitory receptors, most changes were observed in CD56dim NK cells. The expressions of CD16 decreased at END and returned at POST 30. The expressions of CD212 dropped from END to POST 30. In contrast, the expressions of CD335 increased from END to POST 30. Exceptionally, changes in the expressions of CD226 were found in both subsets. The expressions decreased at POST180. CONCLUSION: These results suggest that acute exercise influences the expressions of cell surface molecules and receptors. Changes were mainly observed at END and POST 30 in CD56dim NK cell. However, the delayed changes were also seen in some receptors. The changes in several receptors were related to cell mobilization. In contrast, the changes in other receptors were not directly related to mobilization and cytotoxicity

Preparation of eco-friendly Fe2VAl-based thermoelectric materials using cast iron scrap chips as a source material

This study investigates the upgraded recycling of cast-iron scrap chips in synthesising Heusler alloys Fe2VAl for thermoelectric materials. It mainly examines the microstructure and the thermoelectric performance of the products. The thermoelectric performance showed positive results, as the maximum power factor, the PF value, of p-type 2C.I.-V-Al prepared using cast-iron scrap chips (the prefix ‘C.I.’ presumably stands for ‘cast-iron scrap chips’) was 1604 µWm−1K−2 at 200°C, the highest PF value. Meanwhile, the undoped 2C.I.-V-Al prepared using cast-iron scrap chips showed an approximate two-fold improvement in the power factor value, with 967 µWm−1K−2 at 200°C, a higher PF value than those previously reported. Unfortunately, in this study, the n-type 2C.I.-V-Al specimen made from cast-iron scrap chips could not be fabricated due to the effect of unavoidable impurities in the cast-iron scrap chips. The use of cast-iron scrap chips to produce undoped and p-type 2C.I.-V-Al alloys can contribute towards eco-friendly and cost-effective production processe

The effect of leg hyperthermia using far infrared rays in bedridden subjects with type 2 diabetes mellitus

We examined the effect of leg hyperthermia on oxidative stress in bedridden subjects with type 2 diabetes mellitus using 15-min sessions of far infrared rays over a two-week period. Four subjects (male 1, female 3) incapacitated by a stroke were recruited for this study. All patients were admitted to Takahashi Central Hospital and ate the same hospital meals. Fasting plasma glucose, HbA1c, tumor necrosis factor (TNF)alpha, free fatty acid, leptin, adiponectin and plasma 8-epi-prostaglandin F2alpha (8-epi-PGF2alpha) levels as a marker of oxidative stress were measured on admission, just before and 2 weeks after local heating of the leg. Results showed that plasma total 8-epi-PGF2alpha levels were decreased significantly while TNFalpha levels were increased significantly. On the other hand, glucose, HbA1c, free fatty acid, leptin and adiponectin levels were not changed during the study period. These results suggest that repeated leg hyperthermia may protect against oxidative stress.</p