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Mitarai O, Xiao C, McColl D, Dreval M, Hirose A, Peng M. Plasma current start-up by the outer ohmic heating coils in the Saskatchewan TORus Modified (STOR-M) iron core tokamak. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:033508. [PMID: 25832230 DOI: 10.1063/1.4915316] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A plasma current up to 15 kA has been driven with outer ohmic heating (OH) coils in the STOR-M iron core tokamak. Even when the inner OH coil is disconnected, the outer OH coils alone can induce the plasma current as primary windings and initial breakdown are even easier in this coil layout. This result suggests a possibility to use an iron core in a spherical tokamak to start up the plasma current without a central solenoid. The effect of the iron core saturation on the extension of the discharge pulse length has been estimated for further experiments in the STOR-M tokamak.
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Onchi T, McColl D, Dreval M, Wolfe S, Xiao C, Hirose A. Design and implementation of fast charging circuit for repetitive compact torus injector. FUSION ENGINEERING AND DESIGN 2014. [DOI: 10.1016/j.fusengdes.2014.06.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Mills L, Hirose A, Dhillon S, Fortin-Pellerin E, Savard W, Khoo N, Hornberger L. EVOLUTION OF CARDIAC OUTPUT AND FUNCTION THROUGH PERINATAL TRANSITION. Can J Cardiol 2014. [DOI: 10.1016/j.cjca.2014.07.120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Mitarai O, Ding Y, Hubeny M, Lu Y, Onchi T, McColl D, Xiao C, Hirose A. Plasma current sustainment after iron core saturation in the STOR-M tokamak. FUSION ENGINEERING AND DESIGN 2014. [DOI: 10.1016/j.fusengdes.2014.02.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Nishimoto M, Nakamae H, Nakamae M, Hirose A, Hagihara K, Koh H, Nakane T, Terada Y, Hino M. Feasibility of umbilical cord blood transplantation with a myeloablative, reduced toxicity-conditioning regimen. Bone Marrow Transplant 2014; 49:980-1. [PMID: 24710565 DOI: 10.1038/bmt.2014.60] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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McBrien A, Howley L, Yamamoto Y, Hutchinson D, Hirose A, Sekar P, Jain V, Motan T, Trines J, Savard W, Hornberger LK. Changes in fetal cardiac axis between 8 and 15 weeks' gestation. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2013; 42:653-658. [PMID: 24273201 DOI: 10.1002/uog.12478] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 03/25/2013] [Accepted: 03/28/2013] [Indexed: 06/02/2023]
Abstract
OBJECTIVES To document changes in the normal embryonic/fetal cardiac axis in the late first and early second trimesters of pregnancy. METHODS Images from 188 fetal echocardiograms performed prospectively between 8 and 15 weeks' gestation in 166 healthy pregnancies and in 10 pregnancies with severe fetal heart disease were reviewed. For each echocardiogram, three measurements of the cardiac axis were taken in the axial plane at the level of the four-chamber view. Differences in mean embryonic/fetal cardiac axis at different gestational ages in the healthy pregnancies were compared. RESULTS The mean ± SD embryonic/fetal cardiac axis was 25.5 ± 11.5° from 8 + 0 to 9 + 6 weeks (Group 1), 40.4 ± 9.2° from 10 + 0 to 11 + 6 weeks (Group 2), 49.2 ± 7.4° from 12 + 0 to 12 + 6 weeks (Group 3), 50.6 ± 5.7° from 13 + 0 to 13 + 6 weeks (Group 4) and 48.6 ± 7.3° from 14 + 0 to 14 + 6 weeks (Group 5). Groups 1 and 2 were significantly different from each other and all other groups (P < 0.05). The results for 22 cases with repeat measurements from 8 + 0 to 11 + 6 and 12 + 0 to 14 + 6 weeks confirmed that the embryonic/fetal cardiac axis increased significantly (P < 0.001). In the cases with severe congenital heart disease, the cardiac axis was > 90th centile in four cases and < 10th centile in two cases. CONCLUSIONS The embryonic cardiac axis is relatively midline at 8 weeks and levorotates in the late first trimester. By 12 weeks' gestation, the normal leftward fetal cardiac axis is established and remains stable until at least 14 + 6 weeks. Observation of an abnormal cardiac axis in some cases of severe congenital heart disease prior to 15 weeks' gestation may assist in prenatal detection.
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Alhashemi H, Colen T, Hirose A, Alrajaa N, Jain V, Savard W, Stickland M, Davidge S, Hornberger LK. Exploring the Relationship Between Increased Arterial Stiffness and Myocardial Hypertrophy in Infants of Diabetic Mothers. Can J Cardiol 2013. [DOI: 10.1016/j.cjca.2013.07.117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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Yamamoto Y, Khoo NS, Brooks PA, Savard W, Hirose A, Hornberger LK. Severe left heart obstruction with retrograde arch flow influences fetal cerebral and placental blood flow. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2013; 42:294-299. [PMID: 23456797 DOI: 10.1002/uog.12448] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 01/19/2013] [Accepted: 02/20/2013] [Indexed: 06/01/2023]
Abstract
OBJECTIVE Decreased middle cerebral artery (MCA) pulsatility index (PI) is a marker of fetal brain-sparing in placental insufficiency and it is also found in fetuses with severe congenital heart disease. This study sought to explore the impact of anatomical subtypes in fetal heart disease on MCA-PI and head growth. METHODS We retrospectively reviewed fetal echocardiograms of pregnancies complicated by fetal hypoplastic left heart syndrome (HLHS; n = 42) with and without anatomic coarctation (n = 28 and n = 10, respectively), isolated severe aortic coarctation (n = 21), D-transposition of the great arteries (TGA; n = 11) and pulmonary outflow tract obstruction without forward flow across the pulmonary valve (POTO; n = 15), comparing observations with gestational age-matched controls (n = 89). No fetus had major extracardiac pathology or aneuploidy. MCA and umbilical artery (UA) PI, the cerebral placental ratio (CPR = MCA-PI/ UA-PI) and neonatal head circumference were obtained and expressed as Z-scores. RESULTS Lower MCA-PI, higher UA-PI and lower CPR were observed in fetal HLHS and isolated coarctation with reversed arch flow (n = 6) (P < 0.001) but not TGA, POTO or isolated coarctation with antegrade arch flow (n = 15) compared with controls. No difference was found between HLHS with anatomical coarctation and those without; however, MCA-PI correlated positively with neonatal head circumference in HLHS with reversed distal arch flow (r = 0.33, P < 0.05). CONCLUSIONS Severe left heart obstruction with reversed aortic arch flow is associated with altered fetal cerebral blood flow, and in these conditions, MCA-PI positively correlates with head growth. Anatomical arch obstruction itself may not be a contributing factor to altered MCA flow in fetal HLHS.
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Li XJ, He LL, Li YS, Yang Q, Hirose A. Direct coating adherent diamond films on Fe-based alloy substrate: the roles of Al, Cr in enhancing interfacial adhesion and promoting diamond growth. ACS APPLIED MATERIALS & INTERFACES 2013; 5:7370-7378. [PMID: 23829602 DOI: 10.1021/am401709j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Direct CVD deposition of dense, continuous, and adherent diamond films on conventional Fe-based alloys has long been considered impossible. The current study demonstrates that such a deposition can be realized on Al, Cr-modified Fe-based alloy substrate (FeAl or FeCrAl). To clarify the fundamental mechanism of Al, Cr in promoting diamond growth and enhancing interfacial adhesion, fine structure and chemical analysis around the diamond film-substrate interface have been comprehensively characterized by transmission electron microscopy. An intermediate graphite layer forms on those Al-free substrates such as pure Fe and FeCr, which significantly deteriorates the interfacial adhesion of diamond. In contrast, such a graphite layer is absent on the FeAl and FeCrAl substrates, whereas a very thin Al-rich amorphous oxide sublayer is always identified between the diamond film and substrate interface. These comparative results indicate that the Al-rich interfacial oxide layer acts as an effective barrier to prevent the formation of graphite phase and consequently enhance diamond growth and adhesion. The adhesion of diamond film formed on FeCrAl is especially superior to that formed on FeAl substrate. This can be further attributed to a synergetic effect including the reduced fraction of Al and the decreased substrate thermal-expansion coefficient on FeCrAl in comparison with FeAl, and a mechanical interlocking effect due to the formation of interfacial chromium carbides. Accordingly, a mechanism model is proposed to account for the different interfacial adhesion of diamond grown on the various Fe-based substrates.
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Hirose A, Maeno Y, Suda K, Fusazaki N, Kado H, Matsuishi T. Serial hemodynamic assessment using Doppler echocardiography in a fetus with left ventricular aneurysm presented as fetal hydrops. J Perinatol 2013; 33:486-9. [PMID: 23719251 DOI: 10.1038/jp.2012.93] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A 22-week fetus presented with a large left ventricular aneurysm, 24 × 21 × 18 mm in size, detected by abnormal four-chamber view, and severe fetal hydrops with pericardial effusion, ascites and skin edema. The aneurysm was thin-walled, hypokinetic, and had enlarged with gestational age, causing compression of the lung. Although the left ventricular function had progressively impaired as expressed by increase in Tei index, hydrops had resolved by 32 weeks of gestation, probably because of maternal digoxin therapy and successful compensation by the right ventricle, as represented by retrograde blood flow in the distal aortic arch via the patent arterial duct. Because of the significant risk of severe cardiorespiratory failure, we transported the mother to a neonatal cardiac surgical center at 38 weeks of gestation. Indeed, the baby showed severe cardiopulmonary failure after birth, showing 100% of cardiothoracic ratio on the chest X-ray film, but was saved by the successful Dor procedure, including surgical resection of the aneurysm at 10 h of life. In this case, serial echocardiographic evaluation can allow us to monitor the hemodynamics and lead to successful postnatal management.
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Ue M, Ikebe N, Munekage K, Ochi T, Hirose A, Kataoka H, Fujimoto S, Kikuchi K, Okuhara Y, Ono M, Saibara T. Hepatocyte destruction with enhanced collagen synthesis: characteristic feature of chronic hepatitis C patients on haemodialysis. J Viral Hepat 2013; 20:350-7. [PMID: 23565618 DOI: 10.1111/jvh.12031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 10/01/2012] [Indexed: 12/09/2022]
Abstract
Hepatitis C virus (HCV) infection is frequent among patients with end-stage renal disease on haemodialysis and is considered to be an independent risk factor for mortality in this setting. However, only a few of these patients are treated with anti-hepatitis virus treatment before the development of end-stage renal disease. Recent guidelines recommend identification of patients with good prognoses who are in need of interferon treatment, but we know little of patients who must be treated urgently. Ninety-eight patients on haemodialysis (48 anti-HCV-positive and 50 anti-HCV-negative patients) were enrolled in this study; HCV RNA was detected in 43 anti-HCV-positive patients. Univariate analysis and multivariate regression analysis were applied to identify variables independently associated with persistent HCV infection. Seven variables were proven to be associated with persistent HCV infection. Among them, type IV collagen 7S and N-terminal propeptide of type III procollagen (P-III-P) were defined as independent variables useful in distinguishing HCV RNA-positive patients from HCV RNA-negative patients with 0.91 sensitivity, 0.91 specificity, 0.89 positive predictive value and 0.93 negative predictive value. Our observations suggest that hepatocyte destruction with enhanced liver fibrosis is a characteristic clinical feature of persistent HCV infection. Type IV collagen 7S of ≥ 5 ng/mL and/or P-III-P of ≥ 5 U/mL would be useful markers to identify patients in need of interferon treatment, which supports the idea of the Kidney Disease: Improving Global Outcomes guidelines that a good prognosis in patients with HCV infection on haemodialysis should prompt consideration for IFN treatment when applicable.
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Nishimoto M, Nakamae H, Koh H, Nakane T, Nakamae M, Hirose A, Hagihara K, Nakao Y, Terada Y, Ohsawa M, Hino M. Risk factors affecting cardiac left-ventricular hypertrophy and systolic and diastolic function in the chronic phase of allogeneic hematopoietic cell transplantation. Bone Marrow Transplant 2012; 48:581-6. [PMID: 23528643 DOI: 10.1038/bmt.2012.179] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chronic impairment of cardiac function can be an important health risk and impair the quality of life, and may even be life-threatening for long-term survivors of allogeneic hematopoietic cell transplantation (HCT). However, risk factors for and/or the underlying mechanism of cardiac dysfunction in the chronic phase of HCT are still not fully understood. We retrospectively investigated factors affecting cardiac function and left-ventricular hypertrophy (LVH) in the chronic phase of HCT. Sixty-three recipients who survived for >1 year after receiving HCT were evaluated using echocardiography. Based on simple linear regression models, high-dose TBI-based conditioning was significantly associated with a decrease in left-ventricular ejection fraction and the early peak flow velocity/atrial peak flow velocity ratio, following HCT (coefficient=-5.550, P=0.02 and coefficient=-0.268, P=0.02, respectively). These associations remained significant with the use of multiple linear regression models. Additionally, the serum ferritin (s-ferritin) level before HCT was found to be a significant risk factor for LVH on multivariable logistic analysis (P=0.03). In conclusion, our study demonstrated that a myeloablative regimen, especially one that involved high-dose TBI, impaired cardiac function, and that a high s-ferritin level might be associated with the development of LVH in the chronic phase of HCT.
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Ichihara H, Nakamae H, Hirose A, Nakane T, Koh H, Hayashi Y, Nisimoto M, Nakamae M, Terada Y, Koh S, Yoshimura T, Aimoto M, Manabe M, Hagiwara K, Hino M. Immunoglobulin Prophylaxis against Cytomegalovirus Infection in Patients at High Risk Ofinfection Following Allogeneic Hematopoietic Cell Transplantation. Ann Oncol 2012. [DOI: 10.1016/s0923-7534(20)32538-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Hirose A, Yamawaki M, Kanno S, Igarashi S, Sugita R, Ohmae Y, Tanoi K, Nakanishi TM. Development of a 14C detectable real-time radioisotope imaging system for plants under intermittent light environment. J Radioanal Nucl Chem 2012. [DOI: 10.1007/s10967-012-2130-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Ichihara H, Nakamae H, Hirose A, Nakane T, Koh H, Hayashi Y, Nishimoto M, Nakamae M, Yoshida M, Bingo M, Okamura H, Aimoto M, Manabe M, Hagihara K, Terada Y, Nakao Y, Hino M. Immunoglobulin prophylaxis against cytomegalovirus infection in patients at high risk of infection following allogeneic hematopoietic cell transplantation. Transplant Proc 2012; 43:3927-32. [PMID: 22172874 DOI: 10.1016/j.transproceed.2011.08.104] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 08/15/2011] [Accepted: 08/31/2011] [Indexed: 11/28/2022]
Abstract
Reports on the efficacy of intravenous immunoglobulin (IVIG) prophylaxis against cytomegalovirus (CMV) infection after allogeneic hematopoietic cell transplantation (HCT) have often sparked controversy. In addition, we are not aware of any study that has examined whether prophylaxis with IVIG affects the incidence of CMV infection in high-risk patients--those who are elderly or have received human leukocyte antigen (HLA) mismatched HCT. In the present open-label, phase II study, we addressed this question. We enrolled 106 patients in the study. The cumulative incidences of CMV infection at 100 days after HCT were similar in the intervention and the control groups (68% and 64%, P=.89; 89% and 87%, P=.79, respectively, for patients 55 years or older and those who received HLA-mismatched HCT). In those who received HLA-mismatched HCT, 1-year overall survival after HCT was 46% in the intervention group and 40% in the control group (P=.31); for age≥55 years, the corresponding values were 46% and 40% (P=.27). Our data showed that prophylaxis with regular polyvalent IVIG did not affect the incidence of CMV infections or survival among older patients or those who receive HLA-mismatched HCT.
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Ono A, Takahashi M, Kawamura T, Kamata E, Hirata-Koizumi M, Hirose A. An evaluation of structure-based toxicity classification and TTC approach for assessing safety of existing industrial chemicals with JECDB. Toxicol Lett 2011. [DOI: 10.1016/j.toxlet.2011.05.351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Hirose A, Ono A, Hirata-Koizumi M, Serizawa H, Sunaga M, Furukawa M, Kamata E, Nishimura T. Repeated dose 28-day oral toxicity studies of single- and multi-walled carbon nanotubes in rats. Toxicol Lett 2011. [DOI: 10.1016/j.toxlet.2011.05.961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Kubota R, Tahara M, Shimizu K, Kobayashi N, Sugimoto N, Hirose A, Nishimura T. Time-dependent biodistribution of C60 in rat after tail-vein administration. Toxicol Lett 2011. [DOI: 10.1016/j.toxlet.2011.05.966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Dreval M, Xiao C, Elgriw S, Trembach D, Wolfe S, Hirose A. Determination of radial location of rotating magnetic islands by use of poloidal soft x-ray detector arrays in the STOR-M tokamak. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2011; 82:053503. [PMID: 21639500 DOI: 10.1063/1.3593110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A technique is presented for determining the radial location of the rotating magnetic islands in the STOR-M tokamak by use of soft x-ray (SXR) detector arrays. The location is determined by examining the difference in the integrated SXR emission intensities through two adjacent lines of sight. A model for calculating dependence of the line integrated SXR emission intensity on the radius, the mode numbers and the magnetic island geometry, has been developed. The SXR difference signal shows phase inversion when the impact parameter of the line of sight sweeps across the magnetic islands. Experimentally, the difference SXR signals significantly reduce noise and suppress the influence of background plasma fluctuations through common mode rejection when a dominant mode exists in the STOR-M tokamak. The radial locations of the m = 2 magnetic islands have been determined under several experimental conditions in the STOR-M discharges. With the decrease in the tokamak discharge current and thus the increase of the safety factor at the edge, the radial location of the m = 2 magnetic islands has been found to move radially inward.
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Asai T, Itagaki H, Numasawa H, Terashima Y, Hirano Y, Hirose A. A compact and continuously driven supersonic plasma and neutral source. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2010; 81:10E119. [PMID: 21033984 DOI: 10.1063/1.3483213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A compact and repetitively driven plasma source has been developed by utilizing a magnetized coaxial plasma gun (MCPG) for diagnostics requiring deep penetration of a large amount of neutral flux. The system consists of a MCPG 95mm in length with a DN16 ConFlat connection port and an insulated gate bipolar transistor (IGBT) inverter power unit. The power supply consists of an array of eight IGBT units and is able to switch the discharge on and off at up to 10 kV and 600 A with a maximum repetitive frequency of 10 kHz. Multiple short duration discharge pulses maximize acceleration efficiency of the plasmoid. In the case of a 10 kHz operating frequency, helium-plasmoids in the velocity range of 20 km/s can be achieved.
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Maley JM, Sham TK, Hirose A, Yang Q, Bradley MP, Sammynaiken R. Chemical reactions and applications of the reductive surface of porous silicon. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2010; 10:6332-6339. [PMID: 21137727 DOI: 10.1166/jnn.2010.2521] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The chemical reactivity of freshly prepared porous silicon is similar to that of a reducing agent on the surface of the nanocrystallites. Ag+ spontaneously reduces to form Ag0 granular coatings on the surface of porous silicon at the expense of the oxidation of silicon hydride and silicon. Atomic Force Microscopy shows that the thickness and topography of the Ag0 coating depend on the concentration of Ag+ with the porous silicon surface being the limiting reagent. In-situ Raman Spectroscopy shows an Ag layer on the silicon and Si:O layer immediately after etching and exposure to Ag+ and O2 respectively. Ag0 coated on the surface and in the pores of the porous silicon proves to be an excellent material for Surface Enhanced Raman Spectroscopy and the natural low electron affinity on the surface of porous silicon replaces the need for a negative bias to prepare very stable diamond coatings on the surface of silicon.
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Nishimura T, Kubota R, Shimizu K, Tahara M, Obama T, Sugimoto N, Kanno J, Hirose A. Tissue distribution of fullerene after injection into rat tail vein to mimic the absorption from the digestive tract. Toxicol Lett 2010. [DOI: 10.1016/j.toxlet.2010.03.1143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Kanno J, Takagi A, Nishimura T, Hirose A. Nanomaterial toxicology—Importance of chronic toxicity assessment. Toxicol Lett 2010. [DOI: 10.1016/j.toxlet.2010.03.1146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Li YS, Tang Y, Yang Q, Maley J, Sammynaiken R, Regier T, Xiao C, Hirose A. Ultrathin W-Al dual interlayer approach to depositing smooth and adherent nanocrystalline diamond films on stainless steel. ACS APPLIED MATERIALS & INTERFACES 2010; 2:335-338. [PMID: 20356176 DOI: 10.1021/am9007159] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The adherence of diamond coated on steel is commonly low and needs to be strengthened with thick intermediate layers. In this paper, a nanoscale W-Al dual metal interlayer has been applied on SS304 substrates to facilitate deposition of continuous, adherent and smooth diamond thin films. During the microwave plasma-enhanced chemical vapor deposition process, the Al inner layer 30 nm thick diffuses into steel surface inhibiting carbon diffusion and graphitization. The W outer layer 20 nm thick is transformed into W carbides, both preventing carbon diffusion and enhancing diamond nucleation. The diamond films synthesized are of high purity and have smooth surfaces and dense structures. Indentation and shear deformation tests indicate high delaminating tolerance of the diamond films.
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Dreval M, Rohraff D, Xiao C, Hirose A. Retarding field energy analyzer for the Saskatchewan Torus-Modified plasma boundary. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2009; 80:103505. [PMID: 19895062 DOI: 10.1063/1.3247902] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The retarding field energy analyzer (RFA) is a simple and reliable diagnostic technique to measure the ion temperature in the scrape-off layer and edge of magnetic fusion devices. Design and operation features of a single-sided (facing the ion flow) RFA for ion temperature measurements in the Saskatchewan Torus-Modified (STOR-M) tokamak are described. Its compact size (21 x 15 x 20 mm3) allows RFA measurements without perturbing plasma significantly. Both ion and electron temperature have been measured by RFA in the STOR-M tokamak. A method is proposed to correct the effects of ion flow on the ion temperature using the simultaneously measured Mach number. The measured electron temperature is consistent with the previously reported Langmuir probe data. Abnormal behavior of the RFA has been observed in both ion and electron modes when RFA is inserted deep into the plasma.
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