821 research outputs found
Recent advances in deuterium permeation induced transmutation experiments using nano-structured Pd/CaO/Pd multilayer thin film
Permeation induced transmutation reactions, which we originally found in the nanostructured Pd multilayer film composed of Pd and CaO thin film and Pd substrate, have been observed in our laboratory and other research institutes. Recently, Toyota R&D centre reported almost complete replication experiments on the transmutation of Cs into Pr at ICCF-17. We observed transmutation reactions of Cs into Pr, Ba into Sm, W into Pt up to now. Especially, transmutation of Cs into Pr has been confirmed by "in-situ" measurements using x-ray fluorescence spectrometry (XRF) at SPring-8 in Japan. Experimental data that indicates the presence of transmutation have been accumulated and the underlying mechanism for inducing low energy transmutation reactions is gradually becoming clear, although systematic experimental study is still insufficient. The permeation induced transmutation technology would be expected as an innovative nuclear transmutation method for radioactive waste and a new energy source if we would be able to increase the amount of transmutation products. We have been trying to increase the amount of transmutation products these years for the practical application. The following factors are assumed to be important for inducing deuterium permeation transmutation. 1) Local Deuteron Density 2) Electronic Structure Based on this assumption, we applied an electrochemical method to increase the local deuteron density near the surface of the nano-structured Pd multilayer film. We also tried to increase the transmutation products by changing surface electronic state. These recent experimental methods gave us increased transmutation products, gamma-ray emissions, and new implications on Deuterium Permeation Induced Transmutation
Photon radiation calorimetry for anomalous heat generation in NiCu multilayer thin film during hydrogen gas desorption
In order to investigate the anomalous heat effect (AHE) in NiCu multilayer
thin film, photon radiation calorimetry has been developed. Three types of
photon detectors are employed to cover a wide range of wavelengths from 0.3 nm
to 5.5 um, i.e., photon energies from 0.2 to 1.8 eV. In the present work, the
usefullness of the calorimetry is demonstrated for excess heat measurements
with samples of Ni pure, NiCu composite layers, and Cu layer deposited on the
Ni substrate. Direct comparisons of photon radiation spectra with and without
H2 easily showed sample-specific differences in excess heat power. The samples
of NiCu composite layer produced larger excess heat. By incorporating the
measured radiant power into a heat flow model, the excess heat was deduced to
be 4 - 6 W. The energy generated in 80 hours reached to 520 +/- 120 kJ: the
generated energy per hydrogen was at least 460 +/- 108 keV/H atom. This is
definitely not a chemical reaction, but producing energy at the level of
nuclear reactions.Comment: 6 pages, 6 figure
Effects of MDMA on Extracellular Dopamine and Serotonin Levels in Mice Lacking Dopamine and/or Serotonin Transporters
3,4-Methylendioxymethamphetamine (MDMA) has both stimulatory and hallucinogenic properties which make its psychoactive effects unique and different from those of typical psychostimulant and hallucinogenic agents. The present study investigated the effects of MDMA on extracellular dopamine (DAex) and serotonin (5-HTex) levels in the striatum and prefrontal cortex (PFC) using in vivo microdialysis techniques in mice lacking DA transporters (DAT) and/or 5-HT transporters (SERT). subcutaneous injection of MDMA (3, 10 mg/kg) significantly increased striatal DAex in wild-type mice, SERT knockout mice, and DAT knockout mice, but not in DAT/SERT double-knockout mice. The MDMA-induced increase in striatal DAex in SERT knockout mice was significantly less than in wildtype mice. In the PFC, MDMA dose-dependently increased DAex levels in wildtype, DAT knockout, SERT knockout and DAT/SERT double-knockout mice to a similar extent. In contrast, MDMA markedly increased 5-HTex in wildtype and DAT knockout mice and slightly increased 5-HTex in SERT-KO and DAT/SERT double-knockout mice. The results confirm that MDMA acts at both DAT and SERT and increases DAex and 5-HTex
Enhanced Hyperthermia Induced by MDMA in Parkin Knockout Mice
MDMA (3,4-methylenedioxymethamphetamine) is reportedly severely toxic to both dopamine (DA) and serotonin neurons. MDMA significantly reduces the number of DA neurons in the substantia nigra, but not in the nucleus accumbens, indicating that MDMA causes selective destruction of DA neurons in the nigrostriatal pathway, sparing the mesolimbic pathway. Parkinson’s disease (PD) is a neurodegenerative disorder of multifactorial origin. The pathological hallmark of PD is the degeneration of DA neurons in the nigrostriatal pathway. Mutations in the parkin gene are frequently observed in autosomal recessive parkinsonism in humans. Parkin is hypothesized to protect against neurotoxic insult, and we attempted to clarify the role of parkin in MDMA-induced hyperthermia, one of the causal factors of neuronal damage, using parkin knockout mice. Body temperature was measured rectally before and 15, 30, 45, and 60 min after intraperitoneal injection of MDMA (30 mg/kg) at an ambient temperature of 22 ± 2°C. Significantly enhanced hyper-thermia after MDMA injection was observed in heterozygous and homozygous parkin knockout mice compared with wildtype mice, suggesting that parkin plays a protective role in MDMA neurotoxicity
Bubble burst as jamming phase transition
Recently research on bubble and its burst attract much interest of
researchers in various field such as economics and physics. Economists have
been regarding bubble as a disorder in prices. However, this research strategy
has overlooked an importance of the volume of transactions. In this paper, we
have proposed a bubble burst model by focusing the transactions incorporating a
traffic model that represents spontaneous traffic jam. We find that the
phenomenon of bubble burst shares many similar properties with traffic jam
formation by comparing data taken from US housing market. Our result suggests
that the transaction could be a driving force of bursting phenomenon.Comment: 9 pages,12 figure
Interhemispheric Interactions between the Human Primary Somatosensory Cortices
In the somatosensory domain it is still unclear at which processing stage information reaches the opposite hemispheres. Due to dense transcallosal connections, the secondary somatosensory cortex (S2) has been proposed to be the key candidate for interhemispheric information transfer. However, recent animal studies showed that the primary somatosensory cortex (S1) might as well account for interhemispheric information transfer. Using paired median nerve somatosensory evoked potential recordings in humans we tested the hypothesis that interhemispheric inhibitory interactions in the somatosensory system occur already in an early cortical processing stage such as S1. Conditioning right S1 by electrical median nerve (MN) stimulation of the left MN (CS) resulted in a significant reduction of the N20 response in the target (left) S1 relative to a test stimulus (TS) to the right MN alone when the interstimulus interval between CS and TS was between 20 and 25 ms. No such changes were observed for later cortical components such as the N20/P25, N30, P40 and N60 amplitude. Additionally, the subcortically generated P14 response in left S1 was also not affected. These results document the existence of interhemispheric inhibitory interactions between S1 in human subjects in the critical time interval of 20–25 ms after median nerve stimulation
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