Simultaneously optimizing the interdependent thermoelectric parameters in Ce(Ni1−x_{1-x}Cux_x)2_2Al3_3

Substitution of Cu for Ni in the Kondo lattice system CeNi$_2$Al$_3$ results in a simultaneous optimization of the three interdependent thermoelectric parameters: thermoelectric power, electrical and thermal conductivities, where the electronic change in conduction band induced by the extra electron of Cu is shown to be crucial. The obtained thermoelectric figure of merit $zT$ amounts to 0.125 at around 100 K, comparable to the best values known for Kondo compounds. The realization of ideal thermoelectric optimization in Ce(Ni$_{1-x}$Cu$_x$)$_2$Al$_3$ indicates that proper electronic tuning of Kondo compounds is a promising approach to efficient thermoelectric materials for cryogenic application.Comment: 4 pages, 4 figures. Accepted for publication in Physical Review

Approximate span programs

Span programs are a model of computation that have been used to design quantum algorithms, mainly in the query model. It is known that for any decision problem, there exists a span program that leads to an algorithm with optimal quantum query complexity, however finding such an algorithm is generally challenging. We consider new ways of designing quantum algorithms using span programs. We show how any span program that decides a function f can also be used to decide “threshold” versions of the function f, or more generally, approximate a quantity called the span program witness size, which is some property of the input related to f. We achieve these results by relaxing the requirement tha

Ki-Energy (Life-Energy) Protects Isolated Rat Liver Mitochondria from Oxidative Injury

We investigated whether ‘Ki-energy’ (life-energy) has beneficial effects on mitochondria. The paradigm we developed was to keep isolated rat liver mitochondria in conditions in which they undergo heat deterioration (39°C for 10 min). After the heat treatment, the respiration of the mitochondria was measured using a Clarke-type oxygen electrode. Then, the respiratory control ratio (RC ratio; the ratio between State-3 and State-4 respiration, which is known to represent the integrity and intactness of isolated mitochondria) was calculated. Without the heat treatment, the RC ratio was >5 for NADH-linked respiration (with glutamate plus malate as substrates). The RC ratio decreased to 1.86–4.36 by the incubation at 39°C for 10 min. However, when Ki-energy was applied by a Japanese Ki-expert during the heat treatment, the ratio was improved to 2.24–5.23. We used five preparations from five different rats, and the significance of the differences of each experiment was either P < 0.05 or P < 0.01 (n = 3–5). We analyzed the degree of lipid peroxidation in the mitochondria by measuring the amount of TBARS (thiobarbituric acid reactive substances). The amount of TBARS in heat-treated, no Ki-exposed mitochondria was greater than that of the control (no heat-treated, no Ki-exposed). However, the amount was reduced in the heat-treated, Ki-exposed mitochondria (two experiments; both P < 0.05) suggesting that Ki-energy protected mitochondria from oxidative stress. Calcium ions may play an important role in the protection by Ki-energy. Data also suggest that the observed Ki-effect involves, at least, near-infrared radiation (0.8–2.7 μm) from the human body

Five Decades of Research on Mitochondrial NADH-quinone Oxidoreductase (complex I)

NADH-quinone oxidoreductase (complex I) is the largest and most complicated enzyme complex of the mitochondrial respiratory chain. It is the entry site into the respiratory chain for most of the reducing equivalents generated during metabolism, coupling electron transfer from NADH to quinone to proton translocation, which in turn drives ATP synthesis. Dysfunction of complex I is associated with neurodegenerative diseases such as Parkinson’s and Alzheimer’s, and it is proposed to be involved in aging. Complex I has one non-covalently bound FMN, eight to 10 iron-sulfur clusters, and protein-associated quinone molecules as electron transport components. Electron paramagnetic resonance (EPR) has previously been the most informative technique, especially in membrane in situ analysis. The structure of complex 1 has now been resolved from a number of species, but the mechanisms by which electron transfer is coupled to transmembrane proton pumping remains unresolved. Ubiquinone-10, the terminal electron acceptor of complex I, is detectable by EPR in its one electron reduced, semiquinone (SQ) state. In the aerobic steady state of respiration the semi-ubiquinone anion has been observed and studied in detail. Two distinct protein-associated fast and slow relaxing, SQ signals have been resolved which were designated SQNf and SQNs. This review covers a five decade personal journey through the field leading to a focus on the unresolved questions of the role of the SQ radicals and their possible part in proton pumping

Investigation on the Corrosion of Coated Steel Plates with Impact Defect using Divided Steel Plates

A method utilizing divided steel plates was used to investigate the corrosion of coated steel plates with impact defect while continuously submerged in 3% NaCl solution. The polarization behavior of circular divided steel plates was first compared to that of undivided ones. Half-cell potential and polarization resistance results show similar trend in divided and undivided form especially at the later stages of exposure. The method of using circular divided steel plates was then used to monitor the macrocell as well as microcell corrosion in coated steel plates induced with defect. The test results show that the defect causes macrocell corrosion to occur between the defect and sound portions. The impact defect also caused the reduction in the polarization resistance and consequently higher microcell corrosion at the neighbouring sound coated portions