310 results on '"Takahiro Miki"'
Search Results
152. Recycling and Dissipation of Metals
- Author
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Tetsuya Nagasaka, Kenichi Nakajima, Takahiro Miki, Osamu Takeda, and Kazuyo Matsubae
- Subjects
Lead (geology) ,Materials science ,chemistry ,Waste management ,Impurity ,Metallurgy ,chemistry.chemical_element ,Zinc ,Dissipation ,Copper - Published
- 2016
153. Refractory Metals Recovery from Industrial Wastes
- Author
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Mitsutaka Hino, Hironori Murase, Takahiro Miki, Tran Van Long, and Sasaki Yasushi
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Metallurgy ,Oil refinery ,Refractory metals ,Environmental science ,Environmental pollution ,Lubricant ,Natural mineral ,Combustion ,Industrial waste - Abstract
Refractory metals like Mo and V are alloyed in the special steels like heat-resisting, tool, ship and pipe steels for the improvement of their physical and mechanical properties. Most of refractory metals are refined as by-products in the other metals production processes. Recently, it becomes difficult to open new mines up for the environmental pollution issues, and as the results, it pays attention to recover them from industrial wastes as Mo and V resources instead of new mines development, because these wastes contain higher MoS2 in spent lubricant, MoO3 in oil refining catalysis and V2O5 in an domestic heavy oil combustion ash than the natural minerals containing them. In the present work, it was tried that these refractory metals was recovered as Fe-alloys because more than 80% of refractory metals are used as steel alloying elements and the energy consumption for reduction and production to Fe-alloys are less than that of pure refractory metals production.
- Published
- 2016
154. Involvement of the endogenous hydrogen sulfide/Cav3.2 T-type Ca2+channel pathway in cystitis-related bladder pain in mice
- Author
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Atsufumi Kawabata, Takahiro Miki, Maho Matsunami, Toshifumi Tsujiuchi, Kanae Nishiura, Tomoka Ozaki, Yuko Hayashi, Fumiko Sekiguchi, Hiroyuki Nishikawa, Yasumasa Okawa, and Lisa Kubo
- Subjects
Pharmacology ,Mibefradil ,Urinary bladder ,Voltage-dependent calcium channel ,Cyclophosphamide ,Chemistry ,T-type calcium channel ,Nociception ,medicine.anatomical_structure ,Hyperalgesia ,medicine ,medicine.symptom ,Bladder Pain ,medicine.drug - Abstract
Background and purpose Hydrogen sulfide (H(2) S), generated by enzymes such as cystathionine-γ-lyase (CSE) from L-cysteine, facilitates pain signals by activating the Ca(v) 3.2 T-type Ca(2+) channels. Here, we assessed the involvement of the CSE/H(2) S/Ca(v) 3.2 pathway in cystitis-related bladder pain. Experimental approach Cystitis was induced by i.p. administration of cyclophosphamide in mice. Bladder pain-like nociceptive behaviour was observed and referred hyperalgesia was evaluated using von Frey filaments. Phosphorylation of ERK in the spinal dorsal horn was determined immunohistochemically following intravesical administration of NaHS, an H(2) S donor. Key results Cyclophosphamide caused cystitis-related symptoms including increased bladder weight, accompanied by nociceptive changes (bladder pain-like nociceptive behaviour and referred hyperalgesia). Pretreatment with DL-propargylglycine, an inhibitor of CSE, abolished the nociceptive changes and partly prevented the increased bladder weight. CSE protein in the bladder was markedly up-regulated during development of cystitis. Mibefradil or NNC 55-0396, blockers of T-type Ca(2+) channels, administered after the symptoms of cystitis appeared, reversed the nociceptive changes. Further, silencing of Ca(v) 3.2 protein by repeated intrathecal administration of mouse Ca(v) 3.2-targeting antisense oligodeoxynucleotides also significantly attenuated the nociceptive changes, but not the increased bladder weight. Finally, the number of cells staining positive for phospho-ERK was increased in the superficial layer of the L6 spinal cord after intravesical administration of NaHS, an effect inhibited by NNC 55-0396. Conclusion and implications Endogenous H(2) S, generated by up-regulated CSE, caused bladder pain and referred hyperalgesia through the activation of Ca(v) 3.2 channels, one of the T-type Ca(2+) channels, in mice with cyclophosphamide-induced cystitis.
- Published
- 2012
155. Effect of Al2O3 Refractories on Oxygen Content of Molten Fe^|^ndash;Cr Alloy
- Author
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Yuusuke Mizukami, Mitsutaka Hino, and Takahiro Miki
- Subjects
Materials science ,Mechanical Engineering ,Metallurgy ,Alloy ,Metals and Alloys ,chemistry.chemical_element ,engineering.material ,Oxygen ,Chromium ,chemistry ,Mechanics of Materials ,Aluminium ,Materials Chemistry ,engineering ,Oxygen content ,Solid solution - Published
- 2012
156. Recovery of Molybdenum from Copper Slag
- Author
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Tran Van Long, Takahiro Miki, Jose Palacios, Mitsutaka Hino, Mario Sanches, and Yasushi Sasaki
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Materials science ,Metallurgy ,Alloy ,Metals and Alloys ,Slag ,chemistry.chemical_element ,engineering.material ,Condensed Matter Physics ,Copper slag ,Flux (metallurgy) ,chemistry ,Molybdenum ,visual_art ,Molybdenite ,Materials Chemistry ,visual_art.visual_art_medium ,engineering ,Physical and Theoretical Chemistry ,Carbon - Abstract
Slag as by-product of Cu making has been produced in large amounts in Chile, and around 5 million tons of slag are estimated to be disposed every year and 40 to 45 million tons have been accumulated. Typical Chilean Cu slag contains about 0.3 mass% Mo which is the grade of primary mine production of molybdenite and it also contains about 40 mass% of Fe and 1 mass% Cu. Recovery of Mo from Chilean copper slag is quite attractive to secure a stable Mo supply. The feasibility of the recovery of Mo from Cu slag as Fe-Mo alloys by carbon reduction is investigated in the present work. Mo in Cu slag is found to be fully recovered as Fe rich alloy. The recovered Fe rich alloy contains about 0.65mass% Mo and 2.4 mass% Cu. In addition, to use the recovered Fe-Mo alloy in the special steel industry, which is the most important market for molybdenum, Cu in the produced Fe-Mo alloy is successfully decreased from 2.4 mass% to 0.1 mass% by using FeS-Na2S flux. Thus, Mo recovery from Chilean Cu slag can be promising.
- Published
- 2012
157. Henhouse Feeding Style and Salmonella Enteritidis Contamination in Unvaccinated Flocks of Egg Farms, April 1994-March 2001
- Author
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Osamu Watanabe, Masao Ogino, Takayuki Akiyama, Asako Iwamoto, and Takahiro Miki
- Subjects
Veterinary medicine ,General Veterinary ,business.industry ,media_common.quotation_subject ,Salmonella enteritidis ,Outbreak ,Animal husbandry ,Contamination ,Foodborne Illnesses ,Geography ,Hygiene ,Livestock ,Flock ,business ,media_common - Abstract
From April 1994 to March 2001, monitoring tests (surveillance) for contamination of Salmonella Enteritidis (SE) at commercial egg farms and farm traceback inspections for cases of SE foodborne illness were carried out in the Himeji Livestock Hygiene Service Center jurisdiction of Hyogo Prefecture, Japan. SE vaccination was not performed before the outbreak of SE-associated foodborne illness, and SE contamination of a farm was recognized. In the surveillance, the year average percentages of identified SE-positive farms were 6.1% in farms with floor feeding in an open-type henhouse (F-OH) and 12.7% in farms with cage feeding in a windowless-type henhouse (C-WH), but 0% in farms with only cage feeding in an open-type henhouse (C-OH). The highest identified proportion of SE-positive farms among all styles of farms was found (4.3%) in April 1997-March 1999. Farm traceback inspections were performed in 2 of 7 farms feeding by F-OH and in 5 of 9 farms feeding by C-WH in this period. Easier contamination with SE was found for C-WH or F-OH than for C-OH. Ninety percent of the birds (3,632,000 birds at 70 farms) are fed at these easier contamination farms by C-WH (89% of birds in 13% of farms) or F-OH (1% of birds at 10% of farms). Integrated sanitary requirements and SE vaccinations are especially necessary on farms feeding by F-OH or C-WH. Since 1999, these countermeasures have been performed, and SE foodborne illnesses and affected patients in Hyogo Prefecture have gradually decreased.
- Published
- 2012
158. Recovery of Molybdenum from Spent Lubricant
- Author
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Takahiro Miki, Tran Van Long, Mitsutaka Hino, and Yasushi Sasaki
- Subjects
Materials science ,Mechanics of Materials ,Chemistry ,Molybdenum ,Mechanical Engineering ,Metallurgy ,Materials Chemistry ,Metals and Alloys ,chemistry.chemical_element ,Physical and Theoretical Chemistry ,Lubricant ,Condensed Matter Physics - Published
- 2012
159. Linearity enhancement algorithms for I-Q signal generation — DWA and self-calibration techniques
- Author
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Takahiro Miki, S. N. Mohyar, Masahiro Murakami, Osamu Kobayashi, and Haruo Kobayashi
- Subjects
Multi band ,Computer science ,Electronic engineering ,Calibration ,Linearity ,Q code ,Matlab simulation ,Integrated circuit design ,Delta-sigma modulation ,Algorithm ,Signal - Abstract
This paper describes two linearity enhancement algorithms for I-Q signal generation using a multi-bit complex band-pass (BP) ΔΣ DA modulator targeted for communication IC design and testing applications. The first one is a complex multi-band-pass data-weighted-averaging algorithm and the second is a self-calibration algorithm. The generated I, Q signals can be up-converted to a high frequency signal. We present their principles and MATLAB simulation results.
- Published
- 2015
160. ONO-8130, a selective prostanoid EP1 receptor antagonist, relieves bladder pain in mice with cyclophosphamide-induced cystitis
- Author
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Atsufumi Kawabata, Hiroki Okada, Takahiro Miki, Maho Matsunami, Saori Nakamura, and Hidekazu Matsuya
- Subjects
Cyclophosphamide ,medicine.drug_class ,medicine.medical_treatment ,Administration, Oral ,Pain ,Pharmacology ,Dinoprostone ,Drug Administration Schedule ,Mice ,Cystitis ,medicine ,Animals ,Vimentin ,RNA, Messenger ,Prostaglandin E2 ,Bladder Pain ,Pain Measurement ,business.industry ,Urinary Bladder Diseases ,Interstitial cystitis ,medicine.disease ,Receptor antagonist ,Receptors, Prostaglandin E, EP1 Subtype ,Disease Models, Animal ,Anesthesiology and Pain Medicine ,Nociception ,Gene Expression Regulation ,Spinal Cord ,Neurology ,Cyclooxygenase 2 ,Anesthesia ,Hyperalgesia ,Female ,lipids (amino acids, peptides, and proteins) ,Neurology (clinical) ,medicine.symptom ,business ,Signal Transduction ,medicine.drug ,Prostaglandin E - Abstract
Given the previous evidence for involvement of prostanoid EP1 receptors in facilitation of the bladder afferent nerve activity and micturition reflex, the present study investigated the effect of ONO-8130, a selective EP1 receptor antagonist, on cystitis-related bladder pain in mice. Cystitis in mice was produced by intraperitoneal administration of cyclophosphamide at 300mg/kg. Bladder pain-like nociceptive behavior and referred hyperalgesia were assessed in conscious mice. Phosphorylation of extracellular signal-regulated kinase (ERK) in the L6 spinal cord was determined by immunohistochemistry in anesthetized mice. Cyclophosphamide treatment caused bladder pain-like nociceptive behavior and referred hyperalgesia accompanying cystitis symptoms, including increased bladder weight and vascular permeability and upregulation of cyclooxygenase-2 in the bladder tissue. Oral preadministration of ONO-8130 at 0.3-30 mg/kg strongly prevented both the bladder pain-like behavior and referred hyperalgesia in a dose-dependent manner, but had slight effect on the increased bladder weight and vascular permeability. Oral ONO-8130 at 30 mg/kg also reversed the established cystitis-related bladder pain. Intravesical administration of prostaglandin E2 caused prompt phosphorylation of ERK in the L6 spinal cord, an effect blocked by ONO-8130. Our findings strongly suggest that the prostaglandin E2/EP1 system participates in processing of cystitis-related bladder pain, and that EP1 antagonists including ONO-8130 are useful for treatment of bladder pain, particularly in interstitial cystitis. Prostaglandin E2 contributes to cystitis-related bladder pain via EP1 receptors in mice, indicating possible therapeutic usefulness of selective EP1 antagonists.
- Published
- 2011
161. Thermodynamic Analysis for the Controllability of Elements in the Recycling Process of Metals
- Author
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Osamu Takeda, Kazuyo Matsubae, Tetsuya Nagasaka, Takahiro Miki, and Kenichi Nakajima
- Subjects
Work (thermodynamics) ,Engineering ,chemistry.chemical_element ,Impurity ,Pyrometallurgy ,Environmental Chemistry ,Recycling ,Waste management ,business.industry ,Metallurgy ,Temperature ,Slag ,General Chemistry ,Elements ,Copper ,Oxygen ,Controllability ,chemistry ,Metals ,Steel ,visual_art ,Smelting ,visual_art.visual_art_medium ,Tin ,business - Abstract
This study presents the results of chemical thermodynamic analysis on the distribution of elements in the smelting process of metallic materials to examine the controllability of impurities in the pyrometallurgical technique. The results of the present work can give an answer against the frequently given question; "Which impurity element can be removable in metallurgical process?" or "How far can the impurity level be controlled?". The proposed method was applied to estimate the distribution of 29 elements for a copper converter and 26 elements for a steel-making process and shows the distribution tendency of elements among the gas, slag, and metal phases as well as clarifying which metals can be recovered or removed from secondary resources in metallurgical processes. The effects of temperature, oxygen partial pressure, and slag composition on the distribution ratio of elements were also evaluated, and the removal limit or controllability of impurity in these two processes was presented. This study results in thermodynamic features of various elements in the pyrometallurgical process and also shows, even by varying process parameters such as temperature and oxygen partial pressure, no drastic improvement of removal efficiency should be expected, except for lead and tin in copper.
- Published
- 2011
162. Effect of Fe3C on Carburization and Smelting Behavior of Reduced Iron in Blast Furnace
- Author
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Kotaro Sato, Takuro Noguchi, Takahiro Miki, Mitsutaka Hino, and Yasushi Sasaki
- Subjects
Blast furnace ,Materials science ,Hydrogen ,Cementite ,business.industry ,Mechanical Engineering ,Metallurgy ,Metals and Alloys ,Iron oxide ,chemistry.chemical_element ,Direct reduced iron ,Steelmaking ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,Smelting ,Materials Chemistry ,business ,Blast furnace gas - Abstract
Suppression of CO2 discharged from iron- and steel- making companies is an example of the biggest issues for the protection of global environment and sustainable growth of steelmaking industry. One of the efforts made to decrease the emission of CO2 in ironmaking process is blowing of hydrogen gas into blast furnace. Hydrogen gas can reduce iron oxide and form harmless H2O. Cementite (Fe3C) may be formed by introduction of hydrogen into blast furnace and play an important role on carburization and smelting behavior of reduced iron. The conditions that Fe3C was formed were experimentally determined by changing CO–CO2–H2 gas composition in the present work. As the result, it was found that there is a possibility of Fe3C formation by hydrogen gas introduction into blast furnace. Therefore, the effect of Fe3C on smelting behavior of reduced iron was also observed, and it was confirmed that the presence of Fe3C will have positive effect on enhancing carburization and smelting of reduced iron.
- Published
- 2011
163. Equilibrium between Ti and O in Molten Fe–Ni, Fe–Cr and Fe–Cr–Ni Alloys Equilibrated with ‘Ti3O5’ Solid Solution
- Author
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Mitsutaka Hino, Takahiro Miki, and Seong Ho Seok
- Subjects
Materials science ,Scanning electron microscope ,Mechanical Engineering ,Metallurgy ,Metals and Alloys ,Analytical chemistry ,chemistry.chemical_element ,Ni oxide ,chemistry ,Mechanics of Materials ,Phase (matter) ,Materials Chemistry ,Sem eds analysis ,Solubility ,Dissolution ,Solid solution ,Titanium - Abstract
The Ti deoxidation equilibrium of Fe–Ni, Fe–Cr and Fe–Cr–Ni alloys saturated with ‘Ti3O5’ and Ti2O3 phase was clarified in previous researches. Solubility of Fe, Cr and/or Ni oxides in ‘Ti3O5’ phase equilibrated with liquid Fe–Ni, Fe–Cr and Fe–Cr–Ni alloys at 1823 K to 1923 K were measured by SEM–EDS. It was confirmed that the solubility of Fe, Cr and/or Ni oxide in ‘Ti3O5’ phase at low Ti content increase with decrease of Ti content in alloys. Titanium content that dissolution of Fe, Cr and/or Ni oxide into ‘Ti3O5’ phase becomes apparent increases with increase of Cr and/or Ni content of the alloys. The activity of Ti deoxidation product, ‘Ti3O5’ phase, equilibrated with Fe–Ni, Fe–Cr and Fe–Cr–Ni alloys was also evaluated by Redlich-Kister type polynomial. Equilibrium between Ti and O at low Ti content of those alloys was analyzed using the activity of ‘Ti3O5’ phase.
- Published
- 2011
164. Prevention of Fluorine Elution from Electric Arc Furnace Reducing Slag into Water
- Author
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Yuuki Nagaike, Mitsutaka Hino, and Takahiro Miki
- Subjects
Waste management ,Elution ,Mechanical Engineering ,Inorganic chemistry ,Metals and Alloys ,Slag ,chemistry.chemical_element ,Electric arc ,chemistry ,Mechanics of Materials ,visual_art ,Phase (matter) ,Materials Chemistry ,visual_art.visual_art_medium ,Fluorine ,Dissolution ,Groundwater ,Electric arc furnace - Abstract
Elution of fluorine from landfill slag by rainwater or groundwater causes serious problems; hence, fixation of fluorine in electric arc furnace reducing slag (EAFRS) is crucial. The phase including fluorine was identified for some EAFRS specimens and confirmed is as (3CaO·2SiO2)·CaF2 in the current work. Experiments to determine the dissolution of fluorine from the EAFRS into water were conducted at pH 4, 7, and 10. It was found that fluorine tended to elute under acidic conditions. Therefore, the elution of fluorine from fluorine-containing substances into water at pH 4 was investigated in detail. It was found that 2(2CaO·SiO2)·CaF2, (3CaO·2SiO2)·CaF2, and CaF2 were unstable, while the 3(3CaO·P2O5)·CaF2 phase was stable; further, fluorine elution from 3(3CaO·P2O5)·CaF2 into water was found to be limited. On the basis of these results, it was concluded that the dissolution of fluorine into water can be suppressed by adding a sufficient amount of P2O5 to EAFRS, so that the formation of unstable fluorine-containing substances is prevented.
- Published
- 2011
165. Magnesium Deoxidation Equilibrium of Molten Fe–Cr–Ni Alloy Expressed by Quadratic Formalism and Redlich-Kister Type Polynomial
- Author
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Ryo Yamamoto, Hiroshi Fukaya, Naoya Satoh, Takahiro Miki, and Mitsutaka Hino
- Subjects
Mechanics of Materials ,Mechanical Engineering ,Materials Chemistry ,Metals and Alloys - Published
- 2011
166. Investigation of Compositional Change of Inclusions in Martensitic Stainless Steel during Heat Treatment by Newly Developed Analysis Method
- Author
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Yasushi Tamura, Atsushi Kumagai, Naoya Satoh, Kunichika Kubota, Toru Taniguchi, Yoichiro Saito, and Takahiro Miki
- Subjects
Materials science ,business.industry ,Scanning electron microscope ,Mechanical Engineering ,Metallurgy ,Metals and Alloys ,Martensitic stainless steel ,engineering.material ,Steelmaking ,law.invention ,Hot working ,Mechanics of Materials ,law ,Materials Chemistry ,Melting point ,engineering ,Inclusion (mineral) ,Crystallization ,Austenitic stainless steel ,business - Abstract
The most important subject in the steelmaking process is the control of non-metallic inclusions. Non-metallic inclusions with a high melting point do not deform during a hot working process because they are relatively hard. Hence, the inclusion composition should be controlled in order to achieve a low melting point to prevent product defects. Therefore, an MnO–SiO2-based inclusion is considered to be one of the preferred systems. Moreover, the heat treatment of austenitic stainless steel has been reported to influence the composition of MnO–SiO2-type inclusions; these inclusions change into MnO–Cr2O3-type, MnO–Nb2O5-type, and MnO–V2O3-type inclusions. In this study, we investigated the influence of heat treatment on the composition of the inclusions in the martensitic stainless steel. In general, a scanning electron microscope–energy dispersive x-ray spectrometer (SEM–EDS) is used for the quantitative analysis of inclusions; however, SEM–EDS cannot simultaneously analyze a large number of inclusions. Therefore, a new technique using the SEM–EDS along with the image analysis software “Particle Analysis” was used for the chemical analysis and the size measurement of a large number of inclusions (hereafter abbreviated as the PA method). The heat-treatment-induced compositional change of the inclusions in martensitic stainless steel was evaluated by using both the analysis methods.
- Published
- 2011
167. Prevention of Chromium Elution from Stainless Steel Slag into Seawater
- Author
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Yusuke Samada, Mitsutaka Hino, and Takahiro Miki
- Subjects
inorganic chemicals ,Materials science ,business.industry ,Elution ,Mechanical Engineering ,Phosphorus ,fungi ,Metallurgy ,technology, industry, and agriculture ,Metals and Alloys ,Oxide ,chemistry.chemical_element ,Slag ,Steelmaking ,chemistry.chemical_compound ,Chromium ,chemistry ,Mechanics of Materials ,visual_art ,otorhinolaryngologic diseases ,Materials Chemistry ,visual_art.visual_art_medium ,Seawater ,business ,Dissolution - Abstract
Utilization of steelmaking slag is indispensable for sustainable growth of steelmaking industry. Steelmaking slag contains nutrition such as phosphorus, silicon and iron and may be utilized as a fertilizer if elution of environmentally regulated elements is negligible. Chromium is contained in stainless steel slag as an oxide and stabilization of this chromium oxide in the slag is very important in the view of environmental protection.Elution behavior of elements from chromium containing phases into seawater was investigated to observe the stability of phases that may exist in steelmaking slag. It was found that the existence of 2CaO·SiO2 enhanced the dissolution of chromium into seawater. Elution behavior of chromium from especially synthesized stainless steel slag into seawater was investigated. Finally, fixation of chromium was conducted by control of mineralogical phase with SiO2 addition to stainless steel slag. Addition of SiO2 to the slag was very effective for prevention of chromium elution into seawater.
- Published
- 2011
168. Decomposition Behavior of Fe3C under Ar Atmosphere
- Author
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Takahiro Miki and Koutarou Ishii
- Subjects
Blast furnace ,Materials science ,Hydrogen ,business.industry ,Cementite ,Mechanical Engineering ,Metallurgy ,Metals and Alloys ,Iron oxide ,chemistry.chemical_element ,Direct reduced iron ,Decomposition ,Steelmaking ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,Smelting ,Materials Chemistry ,business - Abstract
Suppression of CO2 discharged from iron and steelmaking companies is an example of the biggest issues for the protection of global environment and sustainable growth of steelmaking industry. One of the efforts made to decrease the emission of CO2 in ironmaking process is blowing of hydrogen gas into blast furnace. Hydrogen gas can reduce iron oxide and form harmless H2O. Cementite (Fe3C) may be formed by introduction of hydrogen into blast furnace and play an important role on carburization and smelting behavior of reduced iron. In the present work, Fe3C sample was held at 800–1 100 K under Ar atmosphere to clarify the stability and the behavior of Fe3C phase. It was confirmed that metastable Fe3C phase will decompose under Ar atmosphere at 800 K and rapidly decompose at temperature over 900 K. Also, it was found that composite of nano-size C and Fe will form when Fe3C decompose.
- Published
- 2014
169. Thermodynamic Analysis of Contamination by Alloying Elements in Aluminum Recycling
- Author
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Tetsuya Nagasaka, Takahiro Miki, Kenichi Nakajima, Shinichiro Nakamura, Osamu Takeda, and Kazuyo Matsubae
- Subjects
Conservation of Natural Resources ,Chemistry ,Metallurgy ,Aluminium recycling ,Slag ,Scrap ,General Chemistry ,Partial pressure ,Contamination ,Gibbs free energy ,symbols.namesake ,Impurity ,visual_art ,Alloys ,symbols ,visual_art.visual_art_medium ,Thermodynamics ,Environmental Chemistry ,Total pressure ,Aluminum - Abstract
In previous studies on the physical chemistry of pyrometallurgical processing of aluminum scrap, only a limited number of thermodynamic parameters, such as the Gibbs free energy change of impurity reactions and the variation of activity of an impurity in molten aluminum, were taken into account. In contrast, in this study we thermodynamically evaluated the quantitative removal limit of impurities during the remelting of aluminum scrap; all relevant parameters, such as the total pressure, the activity coefficient of the target impurity, the temperature, the oxygen partial pressure, and the activity coefficient of oxidation product, were considered. For 45 elements that usually occur in aluminum products, the distribution ratios among the metal, slag, and gas phases in the aluminum remelting process were obtained. Our results show that, except for elements such as Mg and Zn, most of the impurities occurred as troublesome tramp elements that are difficult to remove, and our results also indicate that the extent to which the process parameters such as oxygen partial pressure, temperature, and flux composition can be changed in aluminum production is quite limited compared to that for iron and copper production, owing to aluminum's relatively low melting point and strong affinity for oxygen. Therefore, the control of impurities in the disassembly process and the quality of scrap play important roles in suppressing contamination in aluminum recycling.
- Published
- 2010
170. Hemoperfusion With an Immobilized PolymyxinâB Fiber Column Decreases Macrophage and Monocyte Activity
- Author
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Katsuhisa Tanjoh, Takeshi Saito, Takahiro Miki, Jun Sato, Hidehiko Kushi, and Yuichiro Sakagami
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Adult ,Male ,endocrine system ,medicine.medical_specialty ,medicine.medical_treatment ,Thermodilution ,Blood Pressure ,Neopterin ,Monocytes ,Sepsis ,chemistry.chemical_compound ,Internal medicine ,medicine ,Humans ,Macrophage ,Prospective Studies ,Aged ,Polymyxin B ,business.industry ,Macrophages ,Monocyte ,Hematology ,Middle Aged ,medicine.disease ,Hemoperfusion ,Systemic inflammatory response syndrome ,Blood pressure ,medicine.anatomical_structure ,Endocrinology ,chemistry ,Nephrology ,Immunology ,Female ,business ,medicine.drug - Abstract
We investigated whether direct hemoperfusion with a polymyxin B column (DHP-PMX) was able to decrease macrophage and monocyte activity in patients with sepsis. Nineteen patients with sepsis were enrolled in the study. They all had signs of systemic inflammatory response syndrome (SIRS) due to infection and a mean arterial blood pressure > or =65 mm Hg (irrespective of the use of catecholamines). A thermodilution catheter was inserted prior to DHP-PMX for intravenous infusion, and DHP-PMX was performed twice within 24 h for 3 h each time. Serum neopterin was measured four times: before DHP-PMX, and 24, 48, 72 h after it had begun. The serum concentrations of neopterin were 654 +/- 234 nmol/L prior to DHP-PMX vs. 573 +/- 196 nmol/L at 24 h, 452 +/- 161 nmol/L at 48 h, and 372 +/- 139 nmol/L at 72 h, showing a significant decrease from 48 h onwards compared with before treatment. These data suggest that DHP-PMX decreases macrophage and monocyte activity.
- Published
- 2009
171. Evaluation Method of Metal Resource Recoverability of Based on Thermodynamic Analysis
- Author
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Kenichi Nakajima, Osamu Takeda, Tetsuya Nagasaka, and Takahiro Miki
- Subjects
Materials science ,business.industry ,Process (engineering) ,Material flow analysis ,Extraction (chemistry) ,Metals and Alloys ,Slag ,Condensed Matter Physics ,Metal ,Resource (project management) ,Mechanics of Materials ,visual_art ,Pyrometallurgy ,Materials Chemistry ,visual_art.visual_art_medium ,Process engineering ,business ,Resource recovery - Abstract
Currently, several metals are commercially recycled from by-products and wastes by metallurgical processing. However, the metallurgical process has each characteristic, which causes limitation for resource recovery. The combinations of elements in secondary resources, such as by-products and wastes, are often different from those in natural resources. There are even combinations that are not present in natural resources. Conventional metallurgical processes have been optimized for economical and efficient extraction of desired elements only from large amount of ores under constant grade. Therefore, in order to extract metals from secondary resources by the conventional metallurgical process, it is necessary to estimate the recoverability of the constituent elements by taking into account their chemical properties well in advance. In particular, analysis for combination of elements is significantly important. In this study, we developed the evaluation method of metal resources recoverability based on thermodynamic analysis, and made clear the element distribution among gas, slag and metal phases during metal recovery based on thermodynamic analysis. In an application of the method shows that Cu, and precious metals (Ag, Au, Pt, Pd) present in mobile phones can be recovered as metals in the pyrometallurgy process of Cu in a converter. Other elements distributed in the slag phase are difficult to recover. The result of our analysis reflects the trends observed in the distribution of metals in copper metallurgy, thereby indicating the validity of our proposed evaluation method.
- Published
- 2009
172. Evaluation Method of Metal Resource Recyclability Based on Thermodynamic Analysis
- Author
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Osamu Takeda, Kenichi Nakajima, Takahiro Miki, and Tetsuya Nagasaka
- Subjects
Materials science ,Process (engineering) ,Mechanical Engineering ,Material flow analysis ,Metallurgy ,Extraction (chemistry) ,Slag ,Condensed Matter Physics ,Metal ,Resource (project management) ,Mechanics of Materials ,visual_art ,Pyrometallurgy ,visual_art.visual_art_medium ,General Materials Science ,Resource recovery - Abstract
Currently, several metals are commercially recycled from by-products and wastes by metallurgical processing. However, the metallurgical process has each characteristic, which causes limitation for resource recovery. The combinations of elements in secondary resources, such as by-products and wastes, are often different from those in natural resources. There are even combinations that are not present in natural resources. Conventional metallurgical processes have been optimized for economical and efficient extraction of desired elements only from large amount of ores under constant grade. Therefore, in order to extract metals from secondary resources by the conventional metallurgical process, it is necessary to estimate the recoverability of the constituent elements by taking into account their chemical properties well in advance. In particular, analysis for combination of elements is significantly important. In this study, we developed the evaluation method of metal resources recyclability based on thermodynamic analysis, and made clear the element distribution among gas, slag and metal phases during metal recovery based on thermodynamic analysis. In an application of the method shows that Cu, and precious metals (Ag, Au, Pt, Pd) present in mobile phones can be recovered as metals in the pyrometallurgy process of Cu in a converter, while Pb and Zn can be recovered as vapor. Other elements distributed in the slag phase are difficult to recover. The result of our analysis reflects the trends observed in the distribution of metals in copper metallurgy, thereby indicating the validity of our proposed evaluation method.
- Published
- 2009
173. Ti Deoxidation Equilibrium in Molten Fe–Ni Alloys at Temperatures between 1823 to 1923 K
- Author
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Takahiro Miki, Seong Ho Seok, and Mitsutaka Hino
- Subjects
Polynomial (hyperelastic model) ,Ti oxides ,Materials science ,Scanning electron microscope ,Mechanical Engineering ,Alloy ,Metals and Alloys ,Analytical chemistry ,engineering.material ,Gibbs free energy ,Field emission microscopy ,symbols.namesake ,Crystallography ,Electron diffraction ,Mechanics of Materials ,Materials Chemistry ,symbols ,engineering ,Electron backscatter diffraction - Abstract
Equilibrium relation between Ti and O in molten Fe–Ni alloy has been investigated at 1873 to 1923 K. Ti oxide equilibrated with molten Fe–Ni alloy has been determined by EBSD (Electron Backscatter Diffraction) pattern analysis using FE-SEM (Field Emission Scanning Electron Microscope). The present results have been numerically analyzed by the excess Gibbs free energy change of mixing for the Fe–Ni–Ti–O system with Redlich–Kister type polynomial. Redlich–Kister type polynomial parameters concerning Ni and Ti were determined as follows,0ΩNi–Ti = 424280−270.40T J/mol (XTi
- Published
- 2009
174. Ti Deoxidation Equilibrium in Molten Fe–Cr and Fe–Cr–Ni Alloys at Temperatures between 1823 K and 1923 K
- Author
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Takahiro Miki, Mitsutaka Hino, and Seong-Ho Seok
- Subjects
Materials science ,Scanning electron microscope ,Mechanical Engineering ,Alloy ,Metallurgy ,Metals and Alloys ,Analytical chemistry ,chemistry.chemical_element ,Pattern analysis ,engineering.material ,Gibbs free energy ,Field emission microscopy ,symbols.namesake ,Electron diffraction ,chemistry ,Mechanics of Materials ,Materials Chemistry ,engineering ,symbols ,Titanium ,Electron backscatter diffraction - Abstract
Titanium deoxidation equilibria between Ti and O in molten Fe–Cr and Fe–Cr–Ni alloys were investigated at temperatures of 1823 to 1923 K. Titanium oxides equilibrated with molten Fe–Cr and Fe–Cr–Ni alloys have been determined by EBSD (Electron Backscatter Diffraction) pattern analysis using FE-SEM (Field Emission Scanning Electron Microscope). Deoxidation product changes from Ti2O3 to Ti3O5 with decrease of Ti content in Fe–Cr and Fe–Cr–Ni alloys.Binary interaction parameters of Redlich–Kister type polynomial between Cr and O was assessed by using the previous experimental result in the Fe–Cr–O system. Experimental result of titanium deoxidation in molten Fe–Cr alloy has been numerically analyzed by the excess Gibbs free energy change of mixing Fe–Cr–Ti–O system with Redlich–Kister type polynomial. Validity of evaluated parameters between Cr–O (ΩCr–O) and Cr–Ti (ΩCr–Ti) was confirmed by comparison with experimental result for Fe–Cr–Ni alloy.Binary interaction parameters of Redlich–Kister type polynomial in present work were evaluated as follows,0ΩCr–O = −52870−24.10T J/mol (XO
- Published
- 2009
175. Criteria for Direct Hemoperfusion With an Immobilized Polymyxin B Fiber Column Based on Oxygen Metabolism
- Author
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Takahiro Miki, Hidehiko Kushi, Katsuhisa Tanjoh, Takeshi Saito, and Yuichiro Sakagami
- Subjects
Adult ,Male ,medicine.medical_specialty ,Time Factors ,medicine.medical_treatment ,chemistry.chemical_element ,Blood Pressure ,Severity of Illness Index ,Oxygen ,Sepsis ,Oxygen Consumption ,medicine ,Humans ,Aged ,Polymyxin B ,Retrospective Studies ,Aged, 80 and over ,business.industry ,Hematology ,Middle Aged ,Hemoperfusion ,medicine.disease ,Shock, Septic ,Anti-Bacterial Agents ,Surgery ,Mean blood pressure ,Blood pressure ,medicine.anatomical_structure ,chemistry ,Nephrology ,Anesthesia ,Shock (circulatory) ,Vascular resistance ,Female ,medicine.symptom ,Gram-Negative Bacterial Infections ,business ,medicine.drug - Abstract
The optimum time for commencement of direct hemoperfusion with a polymyxin B immobilized fiber column (DHP-PMX) in patients with sepsis remains unclear. We retrospectively studied the response to DHP-PMX in relation to parameters of oxygen metabolism in 48 patients with sepsis who were divided into two groups. In the effective group (N = 36), the mean blood pressure increased by at least 10 mm Hg after DHP-PMX. Patients who did not show such a blood pressure elevation were assigned to the non-effective group (N = 12). Before the start of therapy, various parameters (mixed venous oxygen saturation, oxygen delivery index, oxygen consumption index (VO(2)I), oxygen extraction ratio, gastric mucosal-arterial PCO(2) difference, age, systemic vascular resistance index, Acute Physiology and Chronic Health Evaluation II score, and Sequential Organ Failure Assessment score were measured in both groups. These parameters were then compared between the two groups. Only VO(2)I showed a significant difference between the two groups, and all patients in the effective group had a VO(2)I of 100 mL/min/m(2) or more. Based on these results, DHP-PMX should be introduced during the period when VO(2)I is still equal to or greater than 100 mL/min/m(2).
- Published
- 2008
176. Early Hemoperfusion With a Polymyxin B Column Improves Gastric Intramucosal pH in Sepsis
- Author
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Hidehiko Kushi, Takahiro Miki, Jun Sato, Katsuhisa Tanjoh, Yuichiro Sakagami, and Takeshi Saito
- Subjects
Adult ,Male ,medicine.medical_specialty ,Time Factors ,Manometry ,medicine.medical_treatment ,Early goal-directed therapy ,Gastroenterology ,Sepsis ,Internal medicine ,medicine ,Humans ,Prospective Studies ,Aged ,Polymyxin B ,Septic shock ,business.industry ,Central venous pressure ,Hematology ,Hydrogen-Ion Concentration ,Middle Aged ,medicine.disease ,Hemoperfusion ,Shock, Septic ,Anti-Bacterial Agents ,Blood pressure ,Gastric Mucosa ,Nephrology ,Anesthesia ,Shock (circulatory) ,Female ,medicine.symptom ,business ,medicine.drug - Abstract
This study had two purposes. One was to assess gastric intramucosal pH (pHi) after early goal-directed therapy in patients with sepsis and septic shock. The other was to determine whether direct hemoperfusion with a polymyxin B fiber column (DHP-PMX) could improve the pHi if it remained low after early goal-directed therapy. The subjects were 32 patients who underwent early goal-directed therapy within 6 h of a diagnosis of sepsis or septic shock, and who achieved the following conditions: (i) central venous pressure of 8-12 mm Hg; (ii) mean arterial blood pressure >or=65 mm Hg; (iii) urine output >or=0.5 mL/kg/h; and (iv) mixed venous oxygen saturation >or=70%. A gastric tonometer was inserted in each patient and the pHi was measured before DHP-PMX, and at 24, 48, and 72 h after the start of treatment. The pHi was 7.22 +/- 0.04 immediately before DHP-PMX, 7.28 +/- 0.03 (P < 0.05) at 24 h, 7.32 +/- 0.03 (P < 0.01) at 48 h, and 7.34 +/- 0.02 (P < 0.01) at 72 h, showing a significant increase from 24 h onward compared with the pretreatment value. In patients with sepsis and septic shock, the pHi remained low after early goal-directed therapy; however, it was significantly improved from 24 h after the start of DHP-PMX and was normalized from 48 h onwards. These findings suggest that DHP-PMX improves pHi. Because this was a prospective uncontrolled observational study on a limited number of patients, larger multicenter clinical trials are required to more accurately assess the benefits of DHP-PMX.
- Published
- 2008
177. Ionophore Toxicosis in Layer Chicks
- Author
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Mamoru Kameyama, Takuya Nakayama, Yuji Ogura, Osamu Watanabe, Takahiro Miki, and Yoshiyuki Maruo
- Subjects
medicine.medical_specialty ,Endocrinology ,Leg weakness ,Blindness ,Chemistry ,Internal medicine ,medicine ,Ionophore ,Anatomy ,medicine.disease ,Layer (electronics) - Published
- 2008
178. Carburization Degree of Iron Nugget Produced by Rapid Heating of Powdery Iron, Iron Oxide in Slag and Carbon Mixture
- Author
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Yasushi Sasaki, Mitsutaka Hino, Takahiro Miki, and Ko Ichiro Ohno
- Subjects
Decarburization ,Materials science ,Mechanical Engineering ,Metallurgy ,Metals and Alloys ,Iron oxide ,engineering.material ,Direct reduced iron ,Carburizing ,chemistry.chemical_compound ,chemistry ,Iron ore ,Mechanics of Materials ,Smelting ,Cementation (metallurgy) ,Materials Chemistry ,engineering ,Graphite - Abstract
Iron nugget making process by rapid heating reduction of powdery iron ore and pulverized coal mixture is regarded as one of the novel iron-making processes. Iron carburization during smelting reduction is especially important reaction step from the viewpoint of saving energy in this process. If the rate and efficiency of carburization reaction are increased, energy consumption of the process will be reduced to large extent. The purpose of this study is to clarify the carburization degree of iron nugget during smelting reduction of the mixture.The sample was prepared from graphite, electrolytic iron powder and synthetic slag containing iron oxide to simulate iron carburization phenomena during smelting reduction of the mixture in the present work. The sample was quenched immediately after the mixture changed into nugget shape in a rapid heating process. Laser microscope combined with infrared image furnace was used for sample heating and observation of carburization phenomena, and carbon content in the nugget was chemically analyzed after quenching.From above-mentioned investigations, it was revealed that the occurrence of carburization during smelting reduction in the sample mixture is advantageous to obtain higher carbon contain iron nugget.
- Published
- 2008
179. Magnesium Deoxidation Equilibrium of Molten Fe–Ni Alloy Expressed by Quadratic Formalism and Redlich–Kister Type Polynomial
- Author
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Hiroshi Fukaya, Naoya Satoh, Ryo Yamamoto, Takahiro Miki, and Mitsutaka Hino
- Subjects
Magnesium ,Mechanical Engineering ,Numerical analysis ,Metallurgy ,Alloy ,Metals and Alloys ,chemistry.chemical_element ,Iron–nickel alloy ,engineering.material ,Chromium ,Nickel ,Quadratic equation ,chemistry ,Mechanics of Materials ,Materials Chemistry ,engineering ,Chemical equilibrium - Abstract
Magnesium deoxidation equilibrium of molten Fe–Cr–Ni alloy was determined by a chemical equilibrium method at temperature of 1873 to 1973 K. Extreme care was taken of oxygen analysis of the samples. Numerical analysis on Mg deoxidation of molten Fe–Cr–Ni alloy has been carried out by utilizing the model based on Darken's quadratic formalism and Redlich-Kister type polynomial. Magnesium deoxidation equilibrium can be expressed in wide composition region of the Fe–Cr–Ni alloy.
- Published
- 2008
180. Effect of Temperature on Oxygen Activity during Ladle Treatment
- Author
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Johan Björklund, Takahiro Miki, Margareta Andersson, and Per Jönsson
- Subjects
Ladle ,Mechanics of Materials ,Chemistry ,business.industry ,Mechanical Engineering ,fungi ,Metallurgy ,Materials Chemistry ,Metals and Alloys ,chemistry.chemical_element ,business ,Oxygen ,Steelmaking - Abstract
The effect of temperature on oxygen activity in steel was studied in plant trials where temperature and oxygen activity were measured at two depths and at the same time during different parts of la ...
- Published
- 2008
181. Temperature Dependence of Ti Deoxidation Equilibria of Liquid Iron in Coexistence with ‘Ti3O5’ and Ti2O3
- Author
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Woo-Yeol Cha, Mitsutaka Hino, Yasushi Sasaki, and Takahiro Miki
- Subjects
Mechanical Engineering ,Alloy ,Metals and Alloys ,Analytical chemistry ,chemistry.chemical_element ,engineering.material ,Flory–Huggins solution theory ,Oxygen ,Titanium oxide ,Crystallography ,chemistry ,Electron diffraction ,Mechanics of Materials ,Materials Chemistry ,engineering ,Saturation (chemistry) ,Equilibrium constant ,Titanium - Abstract
The equilibrium relation between Ti and O in liquid Fe has been measured only at 1 873 K on the condition of various kinds of titanium oxides saturation in our previous paper. The present work deals with the equilibrium between Ti and O in liquid Fe saturated with 'Ti 3 O 5 ' and Ti 2 O 3 at 1 823 K and 1 923 K for full understanding temperature dependence. Also, equilibrium phase changes of titanium oxides with various Ti contents in molten Fe have been identified as the equilibrium titanium oxides with electron backscatter diffraction (EBSD) pattern analysis technique. The present results have been thermodynamically evaluated combining with previous results on the various thermodynamic values as a function of temperature. The equilibrium constants and the interaction parameters of Wagner's formalism were given as a function of temperature in the present work as follows. Ti 2 O 3 (s) = 2Ti + 3O [-10.61, 0.28
- Published
- 2008
182. Aluminum Deoxidation Equilibrium of Molten Fe–Ni Alloy Coexisting with Alumina or Hercynite
- Author
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Mitsutaka Hino, Takayuki Uenishi, Takahiro Miki, Hirotoshi Kandori, and Atsutaka Hayashi
- Subjects
Materials science ,Hercynite ,Mechanical Engineering ,Metallurgy ,Alloy ,Metals and Alloys ,chemistry.chemical_element ,Iron–nickel alloy ,engineering.material ,Metal ,Nickel ,chemistry ,Mechanics of Materials ,Aluminium ,Critical point (thermodynamics) ,visual_art ,Materials Chemistry ,engineering ,visual_art.visual_art_medium ,Chemical equilibrium - Abstract
Aluminum deoxidation equilibrium of molten Fe–Ni alloy was determined by chemical equilibrium method at temperature of 1873 to 1973 K. Also, critical point in molten Fe–40mass%Ni alloy that coexisted with Al2O3 and FeO·Al2O3 was determined experimentally at 1973 K. Solvent extraction method was applied to improve the analytical accuracy of the low aluminum content in molten Fe–Ni alloy. The relation between aluminum and oxygen contents in molten Fe–Ni alloy equilibrated with Al2O3 or FeO·Al2O3 was estimated in the whole alloy composition range at 1873 to 1973 K by utilizing the metallic solution model based on Darken's quadratic formalism and Redlich–Kister type polynomial.
- Published
- 2008
183. Association between facial expression and PTSD symptoms among young children exposed to the Great East Japan Earthquake: A pilot study
- Author
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Takahiro Miki, Takeo Fujiwara, Claude M. Chemtob, and Rie Mizuki
- Subjects
young children ,Facial expression ,medicine.medical_specialty ,natural disaster ,lcsh:BF1-990 ,Poison control ,Human factors and ergonomics ,Suicide prevention ,Facial emotion reactivity ,Facial Action Coding System ,Facial Expression ,lcsh:Psychology ,natural disasters ,Injury prevention ,medicine ,Earthquakes ,Psychology ,Post-Traumatic Stress Disorders ,Association (psychology) ,Psychiatry ,General Psychology ,Clinical psychology ,Psychopathology ,Original Research - Abstract
Emotional numbing is a symptom of post-traumatic stress disorder (PTSD) characterized by a loss of interest in usually enjoyable activities, feeling detached from others, and an inability to express a full range of emotions. Emotional numbing is usually assessed through self-report, and is particularly difficult to ascertain among young children. We conducted a pilot study to explore the use of facial expression ratings in response to a comedy video clip, and to assess emotional reactivity among preschool children directly exposed to the Great East Japan Earthquake. This study included 23 child participants. Child PTSD symptoms were measured using a modified version of the Parent’s Report of the Child’s Reaction to Stress scale. Children were filmed while watching a 2-minute video compilation of natural scenes (‘baseline video’) followed by a 2-minute video clip from a television comedy (‘comedy video’). Children’s facial expressions were processed using Noldus FaceReader software, which implements the Facial Action Coding System (FACS). We investigated the association between PTSD symptom scores and facial emotion reactivity using linear regression analysis. Children with higher PTSD symptom scores showed a significantly greater proportion of neutral facial expressions, controlling for sex, age and baseline facial expression (p < .05). This pilot study suggests that facial emotion reactivity could provide an index against which emotional numbing could be measured in young children, using facial expression recognition software. This pilot study adds to the emerging literature on using experimental psychopathology methods to characterize children’s reactions to disasters.
- Published
- 2015
184. Kinetics of Circulating Damage-Associated Molecular Patterns in Sepsis
- Author
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Toshiaki Iba and Takahiro Miki
- Subjects
lcsh:Immunologic diseases. Allergy ,Adult ,Male ,medicine.medical_specialty ,Time Factors ,Article Subject ,Immunology ,Inflammation ,Biology ,Procalcitonin ,Sepsis ,Histone H3 ,Internal medicine ,medicine ,Immunology and Allergy ,Nucleosome ,Humans ,Interleukin 6 ,Aged ,Receiver operating characteristic ,General Medicine ,Plasma levels ,Middle Aged ,medicine.disease ,Kinetics ,Endocrinology ,ROC Curve ,biology.protein ,Female ,medicine.symptom ,lcsh:RC581-607 ,Biomarkers ,Research Article - Abstract
Circulating levels of conventional biomarkers and damage-associated molecular patterns were examined in 30 severe sepsis patients (20 survivors and 10 nonsurvivors). Plasma levels of interleukin 6, CRP, and procalcitonin reached their peaks on Day 0 (onset of sepsis) or Day 1 and declined rapidly thereafter despite the persistent severity. In contrast, elevated levels of histone H3, nucleosome, and high-mobility group protein Box 1 remained for longer periods of time. The peak level of histone H3 in the nonsurvivors was higher than that of the survivors (p<0.05on Day 7). The cutoff value of the histone H3 on Day 7 for death was 0.08 AU and the area under the receiver operating characteristic curve showed discriminative powers of 0.74. Measurement of circulating levels of the histone H3 provides additional information to that of the conventional indicators of inflammation for determining the severity of sepsis.
- Published
- 2015
185. Numerical analysis for optical frequency comb generated by semiconductor Mach-Zehnder modulator
- Author
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Hiroshi Yasaka, Koichiro Abe, Nobuhide Yokota, Takahiro Miki, and Eiichi Yamada
- Subjects
Physics ,Silicon photonics ,business.industry ,Physics::Optics ,Electro-optic modulator ,Optical modulation amplitude ,Waveguide (optics) ,Slot-waveguide ,Optical modulator ,Optics ,Optical transistor ,Optoelectronics ,Semiconductor optical gain ,business - Abstract
We investigated an optical frequency comb generated by an InP-based semiconductor Mach-Zehnder (MZ) modulator by using a numerical model that takes into account the nonlinear change of a refractive index and an optical absorption induced by an applied voltage in the modulator. Such nonlinearities are negligible for conventional LiNbO3-based MZ modulators but not negligible for semiconductor MZ modulators. The numerical model quantitatively reproduced our experimental data reported previously. We found that the nonlinearities play an important role to obtain the flat 9-channel optical frequency comb block with an intensity deviation of less than 1 dB, when a moderate RF drive voltage of < 5 V was used. This result was sustained regardless of an RF drive voltage ratio between two arms in the MZ modulator.
- Published
- 2015
186. Hydrometallurgical extraction of zinc from CaO treated EAF dust in ammonium chloride solution
- Author
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Romchat Chairaksa-Fujimoto, Tetsuya Nagasaka, Katsuya Maruyama, and Takahiro Miki
- Subjects
Environmental Engineering ,Hydrometallurgy ,Health, Toxicology and Mutagenesis ,Metallurgy ,chemistry.chemical_element ,02 engineering and technology ,Zinc ,Pollution ,020501 mining & metallurgy ,chemistry.chemical_compound ,0205 materials engineering ,chemistry ,Halogen ,Environmental Chemistry ,Ammonium chloride ,Leaching (metallurgy) ,Selective leaching ,Waste Management and Disposal ,Dissolution ,Electric arc furnace ,Nuclear chemistry - Abstract
Zinc in Electric Arc Furnace dust or EAF dust mainly exists as ZnFe2O4 and ZnO. While ZnO can be simply dissolved into either an acidic or alkaline solution, it is difficult to dissolve ZnFe2O4. In our previous work, we introduced a process called "CaO treatment", a preliminary pyrometallurgical process designed to transform the ZnFe2O4 in the EAF dust into ZnO and Ca2Fe2O5. The halogens and others heavy metals were favorably vaporized during CaO treatment with no essential evaporation loss of zinc and iron, leaving CaO treated dust which consisted mainly of ZnO and Ca2Fe2O5 and no problematic ZnFe2O4 compound. In this work, the selective leaching of zinc over iron and calcium in the CaO treated dust was investigated using an NH4Cl solution. The effects of temperature, reaction time and NH4Cl concentration on dissolution behavior were examined. While most of the zinc in the CaO treated dust was extracted after 2 h at 70 °C with 2 M NH4Cl, only about 20% of calcium was leached in NH4Cl solution. However, the iron did not dissolve and remained as Ca2Fe2O5 in residue. It was confirmed that zinc can be effectively recovered using NH4Cl solution.
- Published
- 2015
187. Innovations in steelmaking technology and hidden phosphorus flows
- Author
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Elizabeth Webeck, Eiji Yamasue, Tadahiro Inazumi, Tetsuya Nagasaka, Takahiro Miki, and Kazuyo Matsubae
- Subjects
Flexibility (engineering) ,Engineering ,Environmental Engineering ,Waste management ,business.industry ,media_common.quotation_subject ,02 engineering and technology ,010501 environmental sciences ,Environmental economics ,Geopolitics ,01 natural sciences ,Pollution ,Steelmaking ,020501 mining & metallurgy ,Resource policy ,0205 materials engineering ,Environmental Chemistry ,Production (economics) ,Quality (business) ,business ,Technology innovation ,Waste Management and Disposal ,Resource utilization ,0105 earth and related environmental sciences ,media_common - Abstract
This article will outline the historical transition in the flow of phosphorus in steelmaking technology, and examine the current and future phosphorus flow in steel production and the peripheral steelmaking processes. History provides many instances of innovative changes in steelmaking processes driven by various issues associated with raw materials which emerged over time, such as supply, quality and cost issues. The major steel countries with a long history, including Sweden and Japan, have shown flexibility in their ability to adapt to the changes in the value of resources and geopolitical conditions over times, and have enacted survival resource utilization measures over many centuries, leading to improvements in their respective steelmaking processes. Considering these success stories, it stands to reason that the ideal state of steelmaking is one with a clear stance with regard to resource policy.
- Published
- 2015
188. Activity measurement of the constituents in molten Fe–B and Fe–B–C alloys
- Author
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Takahiro Miki, Kenjirou Tsujita, Mitsutaka Hino, and Shiro Ban-Ya
- Subjects
Chemistry ,General Chemical Engineering ,Alloy ,Thermodynamics ,General Chemistry ,engineering.material ,Entropy of mixing ,Ternary alloy ,Computer Science Applications ,Gibbs free energy ,symbols.namesake ,Molten state ,Activity measurements ,symbols ,engineering - Abstract
The distribution ratios of Fe and B between molten Fe–B alloy and molten Ag were measured at temperatures between 1573 and 1923 K. Also, distribution ratios of Fe and B between molten Fe–B–C satd. alloys and molten Ag were measured at 1873 K. It was found that the excess Gibbs free energy of mixing in molten Fe–B and Fe–B–C alloys can be expressed by utilizing the Redlich–Kister polynomial. The activity curves of the elements in molten Fe–B alloy and Fe–B–C alloy were estimated.
- Published
- 2006
189. Hemoperfusion With an Immobilized Polymyxin B Fiber Column Reduces Circulating Interleukin-8 Concentrations
- Author
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Jun Nakahara, Katsuhisa Tanjoh, Kazuhiko Okamoto, Takahiro Miki, Yayoi Kawahara, Takeshi Saito, and Hidehiko Kushi
- Subjects
Adult ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Urology ,Sepsis ,Humans ,Medicine ,In patient ,Prospective Studies ,Interleukin 8 ,Aged ,Polymyxin B ,business.industry ,Interleukin-8 ,Membranes, Artificial ,Hematology ,Middle Aged ,medicine.disease ,Hemoperfusion ,Respiration, Artificial ,Anti-Bacterial Agents ,Surgery ,Systemic inflammatory response syndrome ,Blood pressure ,Nephrology ,Female ,SOFA score ,business ,medicine.drug - Abstract
In the present study, we examined whether the performance of hemoperfusion with an immobilized polymyxin B fiber column (DHP-PMX) reduces circulating interleukin-8 concentration in patients with sepsis. Fifteen patients with sepsis satisfying the following criteria were enrolled in the study: (i) signs of systemic inflammatory response syndrome caused by infection; and (ii) mean arterial blood pressure > or =60 mm Hg (irrespective of the use of catecholamines). A thermodilution catheter was inserted prior to DHP-PMX for appropriate intravenous infusion, and the DHP-PMX was carried out twice at 24 h intervals (for 3 h each time). Circulating interleukin-8 concentration was measured seven times. The sequential organ failure assessment (SOFA) score was calculated twice. Circulating interleukin-8 concentration was 55 +/- 15.7 pg/mL before DHP-PMX, while it was 101 +/- 58.8 pg/mL immediately after the first session of treatment. It was 24 +/- 9.0 pg/mL before the second session of DHP-PMX, and it was 28 +/- 8.0 pg/mL immediately after the second session. The IL-8 level was 17 +/- 4.3 pg/mL at 48 h afterward, and 18 +/- 4.3 pg/mL at 72 h afterward, showing a significant decrease from 48 h onwards, compared with before treatment (P < 0.05). The SOFA score was 9 +/- 1.5 and the APACHE II score was 19 +/- 2.0 before DHP-PMX, while the SOFA score was 7.0 +/- 0.9 at 72 h afterward, showing a significant decrease compared with before treatment (P < 0.05). The present findings indicate that DHP-PMX indirectly reduces circulating interleukin-8 concentration and improves SOFA score.
- Published
- 2006
190. Behavior of Ironmaking Slag Permeation to Carbonaceous Material Layer
- Author
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Kousuke Saito, Yasushi Sasaki, Ko Ichiro Ohno, Takahiro Miki, and Misutaka Hino
- Subjects
Packed bed ,Materials science ,Mechanical Engineering ,Metals and Alloys ,Slag ,chemistry.chemical_element ,Mineralogy ,Permeation ,Surface tension ,Contact angle ,chemistry ,Chemical engineering ,Mechanics of Materials ,visual_art ,Materials Chemistry ,visual_art.visual_art_medium ,Wetting ,Layer (electronics) ,Carbon - Abstract
To investigate the slag permeation to packed bed of carbonaceous materials, the measurement of molten slag's densities, surface tensions and dynamic contact angle on carbonaceous materials at relatively low temperatures (from 1 673 to 1 773 K) are carried out by applying the sessile droplet method. The interfacial compositions of slags and carbonaceous materials were examined by SEM/EDX. SiC at carbonaceous material surface was not observed. The variation of measured density, contact angle and surface tension with time were found to be almost negligible with given slag composition and at given temperature. It is reported that carbonaceous material wettability at the temperature of more than 1 873 K was strongly dependent on the slag composition as well as carbon properties. The almost constant contact angel with time in this study can be attributed to the negligible formation of SiC at carbonaceous material surface. The slag permeation model has been developed along with the measurement of physical properties. The maximum retention height of liquid layer on the sphere packing layer is expressed by H c =A/L c +L c /2, where A is constant and H c and L c are the dimensionless slag layer retention height and the dimensionless sphere's diameter, respectively. Slag layer retention height on the carbonaceous material packing layer is evaluated using the measured physical properties. The proposed characteristic length λ(=√ -γL cosθ/pg) in the model can be used to characterize the slag permeation behaviour.
- Published
- 2006
191. Equilibrium between Titanium and Oxygen in Liquid Fe-Ti Alloy Coexisted with Titanium Oxides at 1873 K
- Author
-
Woo-Yeol Cha, Mitsutaka Hino, Yasushi Sasaki, Takahiro Miki, and Tetsuya Nagasaka
- Subjects
Chemistry ,Mechanical Engineering ,Alloy ,Metals and Alloys ,chemistry.chemical_element ,Thermodynamics ,engineering.material ,Flory–Huggins solution theory ,Oxygen ,Gibbs free energy ,Titanium oxide ,Formalism (philosophy of mathematics) ,symbols.namesake ,Mechanics of Materials ,Materials Chemistry ,symbols ,engineering ,Equilibrium constant ,Titanium - Abstract
The equilibrium between Ti and Q has been investigated in molten Fe-Ti alloy saturated with various kinds of titanium oxides at 1 873 K. The present results have been thermodynamically analyzed applying Wagner's formalism as well as Darken's quadratic formalism with the excess Gibbs free energy change of mixing described by Redlich-Kister type polynomial. The equilibrium constants and the interaction parameters of Wagner's formalism were given as follows at 1 873 K in the present work. Ti 2 O 3 (s)=2Ti+3O (0.5
- Published
- 2006
192. Identification of Titanium Oxide Phases Equilibrated with Liquid Fe-Ti Alloy Based on EBSD Analysis
- Author
-
Yasushi Sasaki, Woo-Yeol Cha, Takahiro Miki, and Mitsutaka Hino
- Subjects
Materials science ,Mechanical Engineering ,Alloy ,Metallurgy ,Metals and Alloys ,Crucible ,chemistry.chemical_element ,engineering.material ,Titanium oxide ,Electron diffraction ,chemistry ,Mechanics of Materials ,Phase (matter) ,Materials Chemistry ,engineering ,Equilibrium constant ,Electron backscatter diffraction ,Titanium - Abstract
There are huge quantities of uncertainties on the Ti deoxdiation equilibrium constants and their interaction parameters in the literatures including the recommended values by the Japan Society for the Promotion of Science (JSPS). The main reason of such uncertainties among the previous works is due to the insufficient information of titanium oxide phase in equilibrium with liquid Fe–Ti alloy. The measurement of the equilibrium phase changes of titanium oxides with various Ti contents in molten Fe–Ti alloy has been carried out in the present study. Molten Fe–Ti alloys with various Ti contents have been equilibrated with ‘Ti3O5’ crucibles at 1 873 K. The kinds of Ti oxide at the interface of ‘Ti3O5’ crucible contacted with molten Fe–Ti alloys have been identified as the equilibrium titanium oxides with the electron backscatter diffraction (EBSD) pattern analysis technique. After the ‘Ti3O5’ crucible reacted with molten Fe–Ti alloys adequately and both of them were quenched.The present result on the stable region of equilibrium titanium oxides with Ti contents in Fe–Ti alloy was in good agreement with the thermodynamically calculated results based on the free energies of titanium oxides formation and the activity of Ti in Fe–Ti alloy.
- Published
- 2006
193. Hemoperfusion with an Immobilized Polymyxin B Column Reduces the Blood Level of Neutrophil Elastase
- Author
-
Kazuhiko Okamoto, Katsuhisa Tanjoh, Hidehiko Kushi, Jun Nakahara, Takahiro Miki, and Takeshi Saito
- Subjects
Adult ,Male ,Blood level ,endocrine system ,Time Factors ,Neutrophile ,medicine.medical_treatment ,Sepsis syndrome ,Sensitivity and Specificity ,Sepsis ,Humans ,Medicine ,Aged ,Polymyxin B ,Antibacterial agent ,Aged, 80 and over ,Chromatography ,biology ,business.industry ,Membranes, Artificial ,Hematology ,General Medicine ,Middle Aged ,medicine.disease ,Hemoperfusion ,Nephrology ,Neutrophil elastase ,Immunology ,biology.protein ,Female ,Adsorption ,Leukocyte Elastase ,business ,medicine.drug - Abstract
Background: We investigated whether direct hemoperfusion with an immobilized polymyxin B column (DHP with PMX) could reduce the blood level of neutrophil elastase. Methods: 20 sepsis patients were enrolled in the study. DHP with PMX was performed twice within a 24-hour period. Neutrophil elastase was measured 7 times. Results: Neutrophil elastase was 468 ± 75.1 µg/l, while it was 1,531 ± 201.7 µg/l immediately after the first session, declined to 351 ± 73.9 µg/l before the second session of DHP with PMX, and increased again to 599.3 ± 112.7 µg/l immediately after the second session, 328 ± 73.7 µg/l at 24 h, 264 ± 39.3 µg/l at 48 h, and 230 ± 36.1 µg/l at 72 h after DHP with PMX. The levels from 48 h onwards were significantly lower compared with that before treatment. Conclusion: DHP with PMX has an overall effect that reduces circulating neutrophil elastase levels.
- Published
- 2006
194. Allosteric activation of cytochrome P450 3A4 by efavirenz facilitates midazolam binding.
- Author
-
Tomohiko Ichikawa, Hirofumi Tsujino, Takahiro Miki, Masaya Kobayashi, Chiaki Matsubara, Sara Miyata, Tadayuki Uno, Taku Yamashita, Kohei Takeshita, and Yasushige Yonezawa
- Subjects
CYTOCHROME P-450 ,ALLOSTERIC regulation ,EFAVIRENZ ,MIDAZOLAM ,DRUG interactions - Abstract
1. The purpose of this study is to investigate the heteroactivation mechanism of CYP3A4 by efavirenz, which enhances metabolism of midazolam in vivo, in terms of its binding to CYP3A4 with in vitro spectroscopic methods. 2. Efavirenz exhibited a type II spectral change with binding to CYP3A4 indicating a possible inhibitor. Although dissociation constant (K
d ) was approximated as 520 µM, efavirenz enhanced binding affinity of midazolam as a co-existing drug with an estimated iKd value of 5.6 µM which is comparable to a clinical concentration. 3. Efavirenz stimulated the formation of 1'-hydroxymidazolam, and the product formation rate (Vmax ) concentration-dependently increased without changing the Km . Besides, an efavirenz analogue, [6-chloro-1,4-dihydro-4-(1-pentynyl)-4-(trifluoromethyl)-2H-3,1-benzoxazin-2-one] (efavirenz impurity) slightly facilitated the binding affinity of midazolam in a concentration-dependent manner. These results propose that efavirenz affects midazolambinding via binding to the peripheral site which is apart from the active site of CYP3A4. 4. A molecular dynamics simulation also suggested the bound-efavirenz was repositioned to effector-binding site. As a consequence, our spectroscopic studies clarified the heteroactivation of CYP3A4 caused by efavirenz with a proper affinity to the peripheral site, and we concluded the method can be a useful tool for characterising the potential for drug-drug interactions. [ABSTRACT FROM AUTHOR]- Published
- 2018
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195. Electrostatically Actuated Micromirror Array Assembled by Using Solder Flip Chip Bonding and Electro-Thermal Fuse-Away Tethers
- Author
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Takahiro Miki, Koji Ishikawa, Qiang Yu, and Hiroki Mamiya
- Subjects
Microelectromechanical systems ,Materials science ,business.industry ,Process (computing) ,Rotation ,Finite element method ,Soldering ,Electrode ,Fuse (electrical) ,Electronic engineering ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Flip chip - Abstract
We propose a new electrostatically-actuated micromirror array. Using solder flip chip bonding technology, the desired electrode gap and the mirror rotation range can be easily created and enlarged. The use of solder assembly technology also provides us not only design flexibility but also precise gap height and mirror position control. In the mirror assembly process, a new MEMS transfer method using temporary fuse-away tethers is used to achieve robust and clean batch assembly. The mirror array is designed through FEM analysis and design optimization using a surface response method. The driving power of the optimized mirror system is reduced to one-third that of the initial design. The testing results of the fabricated mirror device show consistency with the predicted mirror performance and assembly precision.
- Published
- 2005
196. Numerical Analysis on Si Deoxidation of Molten Fe, Ni, Fe-Ni, Fe-Cr, Fe-Cr-Ni, Ni-Cu and Ni-Co Alloys by Quadratic Formalism
- Author
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Mitsutaka Hino and Takahiro Miki
- Subjects
Materials science ,business.industry ,Mechanical Engineering ,Numerical analysis ,Metallurgy ,Metals and Alloys ,Thermodynamics ,Steelmaking ,Gibbs free energy ,Metal ,Formalism (philosophy of mathematics) ,symbols.namesake ,Quadratic equation ,Mechanics of Materials ,visual_art ,Materials Chemistry ,visual_art.visual_art_medium ,symbols ,business - Abstract
Numerical analysis on Si deoxidation of molten Fe, Ni, Fe-Ni, Fe-Cr, Fe-Cr-Ni, Ni-Cu and Ni-Co alloys have been carried out. The excess Gibbs free energy change of mixing has described with Redlich-Kister type polynomial using the relation derived from Darken's quadratic formalism. Excellent agreement between present work and experimental results was found for equilibrium Si and O contents in molten Fe, Ni, Fe-Ni, Fe-Cr, Fe-Cr-Ni, Ni-Cu and Ni-Co alloys. Si deoxidation equilibrium of not only one component metal but also alloys can be analyzed numerically using the formula determined in the present work. Also, interaction parameters of Redlich-Kister type polynomial can be easily converted into interaction coefficients with Taylor's series, which are widely used in steelmaking processes.
- Published
- 2005
197. A Time Scale Separation Method for the Coordination of Voltage Controls for SVC and SVR
- Author
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Naoto Yorino, Takahiro Miki, Yuuki Yamato, Yoshifumi Zoka, and Hiroshi Sasaki
- Subjects
Distribution system ,Engineering ,Control theory ,business.industry ,Scale separation ,Voltage control ,Energy Engineering and Power Technology ,Static VAR compensator ,Voltage regulation ,Electrical and Electronic Engineering ,business ,Voltage - Published
- 2004
198. Kinetic Analysis of Iron Carburizaiton during Smelting Reduciton
- Author
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Ko Ichiro Ohno, Mitsutaka Hino, and Takahiro Miki
- Subjects
Blast furnace ,Chemistry ,Mechanical Engineering ,Metallurgy ,Kinetic analysis ,Metals and Alloys ,Energy consumption ,Direct reduced iron ,engineering.material ,Lower energy ,Iron ore ,Mechanics of Materials ,Smelting ,Materials Chemistry ,engineering ,Formation rate - Abstract
The most serious issues in the world are a large amount of energy consumption and generation of greenhouse effect gas from iron-making industry. The main factors of energy consumption are reduction of iron ore and carburization of reduced iron at high temperature. If it is possible to accelerate the rates of iron ore smelting reduction and the succeeding carburization at low temperature, the technology will be very valuable to lower energy consumption in the blast furnace. It is well known that phenomena during smelting reduction are very complicated and the mechanism has not yet been clarified. Therefore, "in-situ" observation of smelting reduction and carburization of iron sample were carried out in our previous work. It was confirmed from the results that iron was carburized without a direct contact with carbonaceous material during smelting reduction. The mechanisms of this unique carburization were discussed and it was obtained a conclusion that formation rate of Fe-C particles caused by smelting reduction mainly determined the overall rate of iron carburization reaction.
- Published
- 2004
199. Dissolution Behavior of Nutrition Elements from Steelmaking Slag into Seawater
- Author
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Mitsutaka Hino, Kiyoteru Shitogiden, Tetsuya Nagasaka, Takayuki Futatsuka, and Takahiro Miki
- Subjects
Period (periodic table) ,business.industry ,Chemistry ,Mechanical Engineering ,Metallurgy ,Metals and Alloys ,Slag ,Artificial seawater ,Steelmaking ,chemistry.chemical_compound ,Mechanics of Materials ,visual_art ,Carbon dioxide ,Materials Chemistry ,visual_art.visual_art_medium ,Seawater ,business ,Dissolution ,Solid solution - Abstract
Suppression of CO 2 and waste such as slags discharged from iron- and steelmaking processes are some of the typical biggest issues for the protection of global environment and sustainable growth of steelmaking industry. Utilization of active phytoplankton growth will be one of the best options to stabilize and suppress carbon dioxide at high-efficiency. Inorganic minerals such as C, O, N, Si, P and Fe are necessary for phytoplankton multiplication. It is crucial for supply of nutrition into seawater effectively for phytoplankton multiplication to understand the dissolution behavior of some elements from steelmaking slags into seawater. Firstly, the morphology of the precipitated phases in steelmaking slags during cooling period was investigated in the present work. Secondary, the dissolution behavior of some elements from steelmaking slags and pure substances such as 4CaO . P 2 O 5 (8.5mass% P), 3CaO . P 2 O 5 (10.0 mass% P) and 2CaO . SiO 2 -3CaO . P 2 O 5 (2.8mass% P) solid solution phase into artificial seawater has also been studied. Thirdly, the dissolution mechanism of elements from steelmaking slags was discussed by using stability diagrams of Si, P and Fe in seawater.
- Published
- 2004
200. Dissolution Behavior of Environmentally Regulated Elements from Steelmaking Slag into Seawater
- Author
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Tetsuya Nagasaka, Takayuki Futatsuka, Kiyoteru Shitogiden, Takahiro Miki, and Mitsutaka Hino
- Subjects
business.industry ,Chemistry ,Mechanical Engineering ,Metallurgy ,Metals and Alloys ,Slag ,Artificial seawater ,Steelmaking ,chemistry.chemical_compound ,Mechanics of Materials ,Ground granulated blast-furnace slag ,visual_art ,Carbon dioxide ,Materials Chemistry ,visual_art.visual_art_medium ,Seawater ,business ,Dissolution ,Earth (classical element) - Abstract
Steelmaking slag contains nutrition such as Si, P and Fe for acceleration of phytoplankton growth. Phytoplankton can fixate carbon dioxide more than any other creatures on the earth. Hence, suppression of CO 2 can be achieved by educing the potential of steelmaking slag as the nutrition for their propagation. When it is considered to supply nutrition from steelmaking slag to seawater, we must avoid hazardous elements dissolution from steelmaking slag into seawater. In the present work, the dissolution behavior of Ca, Mg, Mn and F from steelmaking slags into artificial seawater was studied continuously with our previous paper. The dissolution mechanism of elements from steelmaking slags was discussed again by using stability diagram in seawater.
- Published
- 2004
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